Registration Dossier

Administrative data

Key value for chemical safety assessment

Effects on fertility

Description of key information

In absence of experimental data on Tar acids, Xylenol fraction (CAS 84989-06-0) an analogue read-across approach was conducted:

WoE - o-cresol (RL1; according to TSCA Health Effects Test Guideline for specific organ/tissue toxicity - Reproduction/Fertility effects (EPA, 1983) and GLP, rat): NOAEL (general toxicity; P/F1): 30 mg/kg bw/day; NOAEL (fertility, P/F1): 450 mg/kg bw/day; NOAEL (offspring; F1/F2): 175 mg/kg bw/day

WoE - p-cresol (RL1; according to TSCA Health Effects Test Guideline for specific organ/tissue toxicity - Reproduction/Fertility effects (EPA, 1983) and GLP, rat): NOAEL (general toxicity; P/F1): 30 mg/kg bw/day; NOAEL (fertility, P/F1): 450 mg/kg bw/day; NOAEL (offspring; F1/F2): 175 mg/kg bw/day

WoE - m-cresol (RL1; according to TSCA Health Effects Test Guideline for specific organ/tissue toxicity - Reproduction/Fertility effects (EPA, 1983) and GLP, rat): NOAEL (general toxicity; P/F1): 30 mg/kg bw/day; NOAEL (fertility, P/F1): 450 mg/kg bw/day; NOAEL (offspring; F1/F2): 175 mg/kg bw/day

WoE - mixed xylenols (RL1; according to OECD 422 and GLP, rat): NOAEL (general toxicity): 100 mg/kg bw/day; NOAEL (reproduction) >=245 mg/kg bw/day

WoE - mixed ethylphenols (RL1; according to OECD 422 and GLP, rat): NOAEL (general toxicity): 100 mg/kg bw/day; NOAEL (reproduction) >=245 mg/kg bw/day

Link to relevant study records

Referenceopen allclose all

Endpoint:
two-generation reproductive toxicity
Type of information:
experimental study
Adequacy of study:
weight of evidence
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study
Qualifier:
according to
Guideline:
other: TSCA Health Effects Test Guideline for Specific Organ/Tissue Toxicity - Reproduction/Fertility Effects (EPA 1983)
Deviations:
no
GLP compliance:
yes
Limit test:
no
Species:
rat
Strain:
Sprague-Dawley
Sex:
male/female
Details on test animals and environmental conditions:
TEST ANIMALS
- Source: Charles River Breeding Laboratories, Kingston NY
- Age at study initiation: 6 weeks (P)
- Weight at study initiation: (P) Males: 189-191 g; Females: 141-142 g;

- Housing:
initially 2 /same sex during acclimatisation period; and then singly except for the cohabitation and lactation periods
- Diet ad libitum
- Water ad libitum
- Acclimation period: 2 weeks


ENVIRONMENTAL CONDITIONS
- Temperature (°F): 68 - 74
- Humidity (%): 40 - 60
- Photoperiod (hrs dark / hrs light): 12/12

Route of administration:
oral: gavage
Vehicle:
corn oil
Details on exposure:
PREPARATION OF DOSING SOLUTIONS:
Dosing formulations were prepared by weighing the amount of test chemical into a volumetric flask and diluting to volume with certified corn oil. The resulting solutions were mixed by repeated inversions and stored at room temperature.
Details on mating procedure:
- M/F ratio per cage: 1/1
-Length of cohabitation: 21 days
- Proof of pregnancy: vaginal plug referred to as day 0 of pregnancy
- After 7 days of unsuccessful pairing replacement of first male by another male with proven fertility.
- Further matings after two unsuccessful attempts: no
- After successful mating each pregnant female was caged singly
- Any other deviations from standard protocol: no
Analytical verification of doses or concentrations:
yes
Details on analytical verification of doses or concentrations:
A standard stock solution was prepared (1 mg/mL propanol), which was used to prepare standards ranging form 10 to 100 ng/µL. With these solutions standard curve was generated using HPLC. Dosing formulation concentrations were veryfied by preparing aliquots which were injectd on HPLC column. The measured concentration of each dosing solution was then calculated from the equitation for the standared curve developed by linear regression.
Duration of treatment / exposure:
Exposure period: 27 weeks
Premating exposure period (males): 10 weeks
Premating exposure period (females): 10 weeks
Duration of test: 29 weeks
Frequency of treatment:
P- and F1-generation: once per day, 5 days per week
F1 generation producing F2: once per day, 7 days per week
Details on study schedule:
At day 28-40 post partum F1 animals were selected to be parents of the F2-generation and were gavaged with their respective formulations for at least 11 weeks on 5 days per week.
The F1 animals were approximately 15-17 weeks of age at the initiation of the mating period.
They were dosed from that time point 7 days/week. Mating procedure was performed as done with the P-generation.
Dose / conc.:
30 mg/kg bw/day
Dose / conc.:
175 mg/kg bw/day
Dose / conc.:
450 mg/kg bw/day
No. of animals per sex per dose:
25 rats/sex/dose
Control animals:
yes, concurrent vehicle
Details on study design:
no further data
Positive control:
no data
Parental animals: Observations and examinations:
Mortality: twice daily
General condition: daily throughout the course of the study including skin and fur, eyes and mucous membranes, respiratory symptoms, circulatory system, autonomic and central nervous system, somatomotor activity, behavior pattern
Body weight dertermination:
male, female: initially and then weekly until mating
female during gestation: day 0, 7, 13, 20, post partum day 0, 4, 7, 14, 21
Food concumption:
measured weekly during pre-breed dosing period for P and F 1 generation;
all other phases of this study determination was made visually
Oestrous cyclicity (parental animals):
no data
Sperm parameters (parental animals):
no data
Litter observations:
STANDARDISATION OF LITTERS
- Performed on day 4 postpartum: yes
- If yes, maximum of 8 pups/litter (4/sex/litter as nearly as possible); excess pups were killed and discarded.


PARAMETERS EXAMINED
The following parameters were examined in F1 / F2 offspring:
number and sex of pups, stillbirths, live births, postnatal mortality, presence of gross anomalies, weight gain, physical or behavioural abnormalities


GROSS EXAMINATION OF DEAD PUPS:
yes, for external and internal abnormalities; possible cause of death was not determined for pups born or found dead.
Postmortem examinations (parental animals):
SACRIFICE
- Male animals: All surviving animals after the completion of the mating period
- Maternal animals: All surviving animals after the F1 and F2 litters have been weanded

GROSS NECROPSY
- Gross necropsy consisted of external and internal examinations including the cervical, thoracic, and abdominal viscera.

HISTOPATHOLOGY
Male and female adult rats of the highest doses groups and the controls.
The tissues as indicated below were prepared for microscopic examination and weighted, respectively:
Pituitary, vagina, uterus, ovaries, testes, epididymides, seminal vesicles, prostate, and other tissues with gross lesions identified as being potentially treatment-related.
A complete histopathological examination was conducted for any parental animal dying on test.
Postmortem examinations (offspring):
All pups dying during lactation are necropsied to investigate the cause of death.
At weaning, postnatal day 21, 1 female and 1 male from each F1 litter is selected on a random basis to become parents of the next generation.
The remaining offspring is examined for gross external abnormalities, euthanized and discarded
Statistics:
Levene's test, ANOVA, t-test corredted by bonferroni method, Kruskal-Wallis test, Mann-Whitney U-test, Fisher's exact test
Reproductive indices:
calculated for P and F1 animals:
Mating index (%):
---for males: number of males impregnation females divided through the total number of males paired multiplied by 100
---for females: number of females with copulation plugs divided through the number of females cohabited multiplied by 100

Fertility index(%):
---for males: number of males producing pregnant females divided through number of males impregnating females multiplied by 100
---for females: number of females with copulation plugs divided through the number of females cohabited multiplied by 100

Gestational Index (%):
number of females with live litters divided through number of females pregnant multiplied by 100

Offspring viability indices:
calculated for F1 and F2 animals:
live birth index (%):
number of pups at birth divided through the total number of pups born multiplied by 100
4-day survival index (%):
number of pups surviving 4 days divided through the total number of live pups at birth multiplied by 100
7-day survival index(%):
number of pups surviving 7 days divided through the total number of live pups at birth multiplied by 100
14-day survival index(%):
number of pups surviving 14 days divided through the total number of live pups at birth multiplied by 100
21-day survival index(%):
number of pups surviving 21 days divided through the total number of live pups at birth multiplied by 100

Lactation index (%):
number of pups surviving 21 days through total number of live pups at 4 days multiplied by 100
Clinical signs:
effects observed, treatment-related
Dermal irritation (if dermal study):
not examined
Mortality:
mortality observed, treatment-related
Body weight and weight changes:
effects observed, treatment-related
Food consumption and compound intake (if feeding study):
not specified
Food efficiency:
not specified
Water consumption and compound intake (if drinking water study):
not specified
Ophthalmological findings:
not examined
Haematological findings:
not examined
Clinical biochemistry findings:
not examined
Urinalysis findings:
not examined
Behaviour (functional findings):
not examined
Immunological findings:
not examined
Organ weight findings including organ / body weight ratios:
not specified
Gross pathological findings:
not specified
Neuropathological findings:
not specified
Histopathological findings: non-neoplastic:
not specified
Histopathological findings: neoplastic:
not examined
Other effects:
not specified
Reproductive function: oestrous cycle:
not specified
Reproductive function: sperm measures:
not specified
Reproductive performance:
no effects observed
Mortality: 
8/28 males and 5/25 females at 450 mg/kg bw; 
1/25 females at 30 mg/kg bw

Clinical signs of toxicity occurred in F0 and F1 males and females at 450 mg/kg bw/day and included hypoactivity, ataxia, twitches, tremors, prostration, urine stains, audible respiration, perinasal encrustation (not in F0 males), and perioral wetness occurred at >= 175 mg/kg bw.

Body weight:
F0 adult males, sign. reduced (p<0.01) week 1 to week 13 in the 450 mg/kg bw group; 
F0 adult females: sign. reduced week 1 (p<0.05) in the 450 mg/kg bw-group, gestational weight gain not significantly different from control group, lactational body weight sign. reduced (p<0.05) at d4 at 450 mg/kg bw group

Gross lesions of parental males and females which died prior to scheduled  sacrifice included diffuse, focal or multifocal color changes in the lung and stained skin for males and lung congestion and congestion in the nasal turbinates and erythrocytes on the skin surface for females. There were no treatment related histologic lesions observed in the examination of organs from parental F0 and F1 adults which survived to scheduled sacrifice.

F0 or F1: No reproductive parameters were affected in either of the two generations (mating index of male and females, fertility index of males and females, gestational index).
Key result
Dose descriptor:
NOAEL
Remarks:
general toxicity
Effect level:
30 mg/kg bw/day
Based on:
test mat.
Sex:
male/female
Basis for effect level:
other: >= 175 mg/kg bw/d: clinical signs of toxicity including hypoactivity, ataxia, twitches, tremors, prostration, urine stains, audible respiration, and perioral wetness; 450 mg/kg bw/d: increased mortality, and reduced body weight gain
Key result
Dose descriptor:
NOAEL
Remarks:
fertility
Effect level:
450 mg/kg bw/day
Based on:
test mat.
Sex:
male/female
Basis for effect level:
other: No reproductive parameters were affected in either of the two generations.
Critical effects observed:
not specified
Clinical signs:
effects observed, treatment-related
Dermal irritation (if dermal study):
not examined
Mortality:
not specified
Body weight and weight changes:
effects observed, treatment-related
Food consumption and compound intake (if feeding study):
not specified
Food efficiency:
not specified
Water consumption and compound intake (if drinking water study):
not specified
Ophthalmological findings:
not examined
Haematological findings:
not examined
Clinical biochemistry findings:
not examined
Urinalysis findings:
not examined
Behaviour (functional findings):
not examined
Immunological findings:
not examined
Organ weight findings including organ / body weight ratios:
not specified
Gross pathological findings:
not specified
Neuropathological findings:
not specified
Histopathological findings: non-neoplastic:
not specified
Histopathological findings: neoplastic:
not examined
Other effects:
no effects observed
Reproductive function: oestrous cycle:
not specified
Reproductive function: sperm measures:
not specified
Reproductive performance:
no effects observed
Clinical signs of toxicity occurred in F0 and F1 males and females at 450 mg/kg bw/day and included hypoactivity, ataxia, twitches, tremors, prostration, urine stains, audible respiration, perinasal encrustation (not in F0 males), and perioral wetness occurred at >= 175 mg/kg bw.

Gross lesions of parental males and females which died prior to scheduled  sacrifice included diffuse, focal or multifocal color changes in the lung and stained skin for males and lung congestion and congestion in the nasal turbinates and erythrocytes on the skin surface for females. There were no treatment related histologic lesions observed in the examination of organs from parental F0 and F1 adults which survived to scheduled sacrifice.

F0 or F1: No reproductive parameters were affected in either of the two generations (mating index of male and females, fertility index of males and females, gestational index).
Key result
Dose descriptor:
NOAEL
Remarks:
general toxicity
Effect level:
30 mg/kg bw/day
Based on:
test mat.
Sex:
male/female
Basis for effect level:
other: >= 175 mg/kg bw/d: clinical signs of toxicity including hypoactivity, ataxia, twitches, tremors, prostration, urine stains, audible respiration, and perioral wetness 450 mg/kg bw/d: increased mortality, and reduced body weight gain
Key result
Dose descriptor:
NOAEL
Remarks:
fertility
Effect level:
450 mg/kg bw/day
Based on:
test mat.
Sex:
male/female
Basis for effect level:
other: No reproductive parameters were affected in either of the two generations.
Critical effects observed:
not specified
Clinical signs:
not specified
Dermal irritation (if dermal study):
not examined
Mortality / viability:
mortality observed, treatment-related
Body weight and weight changes:
not specified
Food consumption and compound intake (if feeding study):
not specified
Food efficiency:
not specified
Water consumption and compound intake (if drinking water study):
not specified
Ophthalmological findings:
not examined
Haematological findings:
not examined
Clinical biochemistry findings:
not examined
Urinalysis findings:
not examined
Sexual maturation:
not specified
Organ weight findings including organ / body weight ratios:
not specified
Gross pathological findings:
not specified
Histopathological findings:
not specified
Other effects:
not specified
Behaviour (functional findings):
not examined
Developmental immunotoxicity:
not examined
Still births in the F1 and F2 generations:
in F1 pups increased at 175  mg/kg/day (7/13 of one dam), but not at 450 mg/kg bw/day (low, mid, high dose versus control: 4/290 born pups, 13/312 born pups with 7/13 on one dam, 6/193 born pups)  
in F2 pups increased at 30 and 450 mg/kg bw, but not at 175 mg/kg/bw (low, mid, high dose versus control: 7/307 born pups, 4/265 born pups,9/163 born pups versus 0/318 born pups)

There was some variability in the number of stillborn in control groups  in F1 and F2 generation (2 versus 0). There was no clear dose-dependent effect in both generations (control/low/mid/high dose: F1 pups: 2/4/13/6; F2 pups: 0/7/4/9). 

F1, F2: Pup survival indices in both generations were not affected by treatment (4-day survival index, 7-day survival index, 14-day  surval index 21-day survival index and lactation index), except live birth indices in F2 (but not F1) which were reduced at 30 and 450 mg/kg  bw, but not at 175 mg/kg/day. Without any other effects especially in the 30 mg/kg bw-group it is unclear whether the effects on live birth indices were substance related. 
Key result
Dose descriptor:
NOAEL
Generation:
F1
Effect level:
175 mg/kg bw/day
Based on:
test mat.
Sex:
male/female
Basis for effect level:
other: based on toxic effects in the F2 litters of the high dose group animals and no clear evidence of toxic effects in F1 pups.
Critical effects observed:
not specified
Clinical signs:
not specified
Dermal irritation (if dermal study):
not examined
Mortality / viability:
mortality observed, non-treatment-related
Description (incidence and severity):
Pup survival indices in both generations were not affected by treatment (4-day survival index, 7-day survival index, 14-day  surval index 21-day survival index and lactation index), except live birth indices in F2 (but not F1) which were reduced at 30 and 450 mg/kg  bw, but not at 175 mg/kg/day. Without any other effects especially in the 30 mg/kg bw-group it is unclear whether the effects on live birth indices were substance related. 
Body weight and weight changes:
not specified
Food consumption and compound intake (if feeding study):
not specified
Food efficiency:
not specified
Water consumption and compound intake (if drinking water study):
not specified
Ophthalmological findings:
not examined
Haematological findings:
not examined
Clinical biochemistry findings:
not examined
Urinalysis findings:
not examined
Sexual maturation:
not specified
Organ weight findings including organ / body weight ratios:
not specified
Gross pathological findings:
not specified
Histopathological findings:
not specified
Other effects:
not examined
Behaviour (functional findings):
not examined
Developmental immunotoxicity:
not examined
Still births in the F1 and F2 generations:
in F1 pups increased at 175  mg/kg/day (7/13 of one dam), but not at 450 mg/kg bw/day (low, mid, high dose versus control: 4/290 born pups, 13/312 born pups with 7/13 on one dam, 6/193 born pups)  
in F2 pups increased at 30 and 450 mg/kg bw, but not at 175 mg/kg/bw (low, mid, high dose versus control: 7/307 born pups, 4/265 born pups,9/163 born pups versus 0/318 born pups)
There was some variability in the number of stillborn in control groups  in F1 and F2 generation (2 versus 0). There was no clear dose-dependent effect in both generations (control/low/mid/high dose: F1 pups: 2/4/13/6;  F2 pups: 0/7/4/9). 

F1, F2: Pup survival indices in both generations were not affected by treatment (4-day survival index, 7-day survival index, 14-day  surval index 21-day survival index and lactation index), except live birth indices in F2 (but not F1) which were reduced at 30 and 450 mg/kg  bw, but not at 175 mg/kg/day. Without any other effects especially in the 30 mg/kg bw-group it is unclear whether the effects on live birth indices were substance related. 
Key result
Dose descriptor:
NOAEL
Generation:
F2
Effect level:
175 mg/kg bw/day
Based on:
test mat.
Sex:
male/female
Basis for effect level:
other: based on toxic effects in the F2 litters of the high dose group animals and no clear evidence of toxic effects in F1 pups.
Critical effects observed:
not specified
Key result
Reproductive effects observed:
no
Conclusions:
Reproductive toxicity was examined in a two-generation toxicity study according to TSCA Health Effects Test Guideline for specific organ/tissue toxicity - Reproduction/Fertility effects. Sprague-Dawley rats were given daily 0, 30, 175, or 450 mg/kg bw/day p-cresol in corn oil by gavage. No effects on fertility were detected despite overt general toxicity including increased mortality and reduced body weight gain at 450 mg/kg bw and at >= 175 mg/kg bw/day hypoactivity ataxia, twitches, tremors, prostration, urine stains, audible respiration and perioral wetness. Thus, the NOAEL(fertility) was 450 mg/kg bw/day and the NOAEL(general toxicity) was 30 mg/kg bw/day. The NOAEL(offspring) is 175 mg/kg bw/day due to toxic effects in the F2 litters of the high dose group animals and no clear evidence of toxic effects in F1 pups.
Endpoint:
two-generation reproductive toxicity
Type of information:
experimental study
Adequacy of study:
weight of evidence
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study
Qualifier:
according to
Guideline:
other: TSCA Health Effects Test Guideline for specific organ/tissue toxicity - Reproduction/Fertility effects (EPA, 1983)
GLP compliance:
yes
Limit test:
no
Species:
rat
Strain:
Sprague-Dawley
Sex:
male/female
Details on test animals and environmental conditions:
TEST ANIMALS
- Source: Charles River Breeding Laboratories, Kingston, NY
- Age at study initiation: 6 wks (P);
- Weight at study initiation: (P) Males: 189.4 - 191.1 g; Females: 141.1- 142.7 g;
- Housing: initially 2/same sex during acclimation period; and then singly except for the cohabitation and lactation periods
- Diet: ad libitum
- Water: ad libitum
- Acclimation period: 14 days


ENVIRONMENTAL CONDITIONS
- Temperature :68 - 74°F
- Humidity (%): 40 - 60
- Photoperiod (hrs dark / hrs light): 12/12
Route of administration:
oral: gavage
Vehicle:
corn oil
Details on exposure:
PREPARATION OF DOSING SOLUTIONS:
Dosing formulations were prepared by weighing the amount of test chemical into a volumetric flask and diluting to volume with certified corn oil. The resulting solutions were mixed by repeated inversions and stored at room temperature.

Details on mating procedure:
- M/F ratio per cage: 1/1
- Length of cohabitation: 21 days
- Proof of pregnancy: vaginal plug / sperm in vaginal smear referred to as day 0 of pregnancy
- After 7 days of unsuccessful pairing replacement of first male by another male with proven fertility.
- Further matings after two unsuccessful attempts: no
- After successful mating each pregnant female was caged singly
- Any other deviations from standard protocol: no
Analytical verification of doses or concentrations:
yes
Details on analytical verification of doses or concentrations:
A standard stock solution was prepared (1mg/mL propanol),which was used to prepare standards ranging fron 10 to 100 ng/µL. With these solutions a standard curve was generated using HPLC. Dosing formulation concentrations were veryfied by preparing aliquots which were injected onto the HPLC column. The measured concentration of each dosing solution was then calculated from the equitation for the standard curve developed by linear regression.
Duration of treatment / exposure:
Exposure period: 27 w
Premating exposure period (males): 10 w
Premating exposure period (females): 10 w
Duration of test: 29 w
Frequency of treatment:
P- and F1-generation: once/day, 5 days/week
F1- generation producing F2: once/day, 7 days/week
Details on study schedule:
At day 28 - 40 post partum F1 animals selected to be parents of the F2 generation were gavaged with their respective formulations for at least 11 weeks 5 days/week.
The F1 animals were approximately 15 to 17 weeks of age at the initiation of the mating period.
They were dosed from that time point 7 days/week. Mating procedure was performed as done with the P-generation
Dose / conc.:
30 mg/kg bw/day (actual dose received)
Dose / conc.:
175 mg/kg bw/day (actual dose received)
Dose / conc.:
450 mg/kg bw/day (actual dose received)
No. of animals per sex per dose:
25 rat/sex/dose
Control animals:
yes, concurrent vehicle
Details on study design:
no further data
Positive control:
no data
Parental animals: Observations and examinations:
Mortality: twice daily
General conditon: daily throughout the course of the study including skin and fur, eyes and mucous membranes, respiratory symptoms, circulatory system, autonomic and central nervous system, somatomotor activity, behavior pattern
Body weight determination
male, female: initially and then weekly until mating
female during gestation: day 0, 7, 13, 20, post partum: day 0, 4, 7, 14, 21
Food consumption
measured weekly during pre-breed dosing period for P and F1 generation; all other phases of this sutdy determination was made visually

















Oestrous cyclicity (parental animals):
no data
Sperm parameters (parental animals):
no data
Litter observations:
STANDARDISATION OF LITTERS
- Performed on day 4 postpartum: yes
- If yes, maximum of 8 pups/litter (4 sex/litter as nearly as possible); excess pups were killed and discarded.


PARAMETERS EXAMINED
The following parameters were examined in F1 / F2 offspring:
number and sex of pups, stillbirths, live births, postnatal mortality, presence of gross anomalies, weight gain, physical or behavioural abnormalities


GROSS EXAMINATION OF DEAD PUPS:
yes, for external and internal abnormalities; possible cause of death/was not determined for pups born or found dead.
Postmortem examinations (parental animals):
SACRIFICE
- Male animals: All surviving animals after the completion of the mating period
- Maternal animals: All surviving animals after the F1 and F2 litters have been weaned

GROSS NECROPSY
- Gross necropsy consisted of external and internal examinations including the cervical, thoracic, and abdominal viscera.
A complete gross necropsy was conducted for any parental animal dying on test.

HISTOPATHOLOGY
Male and female adult rats of the highest dose groups and the controls.
The tissues as indicated below, were prepared for microscopic examination and weighed, respectively:
pituitary, vagina, uterus, ovaries, testes, epididymides, seminal vesicles, prostate and other tissues with gross lesions identified as being potentially treatment-related.
A complete histopathological examination was conducted for any parental animal dying on test.
Postmortem examinations (offspring):
All pups dying during lactation are necropsied to investigate the cause of death.
At weaning, postnatal day 21, 1 female and 1 male from each F1 litter is selected on a random basis to become parents of the next generation.
The remaining offspring is examined for gross external abnormalities, euthanized and discarded.
Statistics:
Levine's test, ANOVA, t-test corrected by Bonferroni method, Kruskal-Wallis test, Mann Whitney U-test, Fishers exact test
Reproductive indices:
calculated for P and F1 animals:
Mating Index (%):
---for males: number of males impregnating females divided through the total number of males paired multiplied by 100
---for females: number of females with copulation plugs divided through the number of females cohabited multiplied by 100

Fertility Index(%):
---for males: number of males producing pregnant females divided through number of males impregnating females multiplied by 100
---for females: number of pregnant females divided through number of plug-positive females multiplied by 100

Gestational Index (%)
number of females with live litters divided through number of females pregnant multiplied by 100
Offspring viability indices:
calculated for F1 and for F2 animals:
live birth index
number of live pups at birth divided through the toal number of pups born
4-Day Survival Index (%):
number of pups surviving 4 days divided through total number of live pups at birth multiplied by 100
7-Day Survival Index(%):
number of pups surviving 7 days divided through total number of live pups at 4 days multiplied by 100
14- Day Survival Index (%):
number of pups surviving 14 days divided through total number of live pups at 7 days multiplied by 100
21-day survival index (%):
number of pups surviving 21 days divided through total number of live pups at 14 days multiplied by 100
Lactation index (%):
number of pups surviving 21 days divided through total number of live pups at 4 days multiplied by 100
Clinical signs:
effects observed, treatment-related
Dermal irritation (if dermal study):
not examined
Mortality:
mortality observed, treatment-related
Body weight and weight changes:
effects observed, treatment-related
Food consumption and compound intake (if feeding study):
not specified
Food efficiency:
not specified
Water consumption and compound intake (if drinking water study):
not specified
Ophthalmological findings:
not examined
Haematological findings:
not examined
Clinical biochemistry findings:
not examined
Urinalysis findings:
not examined
Behaviour (functional findings):
not examined
Immunological findings:
not examined
Organ weight findings including organ / body weight ratios:
not specified
Gross pathological findings:
no effects observed
Neuropathological findings:
not specified
Histopathological findings: non-neoplastic:
no effects observed
Histopathological findings: neoplastic:
not examined
Other effects:
not specified
Reproductive function: oestrous cycle:
not specified
Reproductive function: sperm measures:
not specified
Reproductive performance:
no effects observed
CLINICAL SIGNS AND MORTALITY (PARENTAL ANIMALS)
P, pre-breed period:
450 mg/kg bw
clinical signs: hypoactivity, ataxia, twitches, tremors, prostration, unkempt appearance (males), urine stains, audible respiration, perinasal encrustration, perioral wetness
mortality 7/25 males; 5/25 females
175 mg/kg bw/day
sacrifice due to trauma of 1/25 male
F1, pre-breed period
450 mg/kg bw/day:clinical signs: hypoactivity, ataxia, twitches, tremors, prostration, unkempt appearance (males), urine stains, audible respiration, perinasal encrustration, perioral wetness(also at 175 mg/kg bw/day)
mortality: 450mg/kg bw/day: 3 males and 4 females
F1 breed period,
mortality during gestation: 1 female in control and 30 and 175 mg/kg bw/day groups and 3 females in the 450 mg/kg bw/day group
mortality during lactation : 3 females at 450 mg/kg bw/day group

BODY WEIGHT (PARENTAL ANIMALS)
P, pre-breed period:
450 mg/kg bw/day, male, female: reduced body weight gain
P, breed period
mortality 450 mg/kg bw 2/20 females; 175 mg/kg bw 1/24 female
F1, pre-breed period:
slightly reduced body weight in males (450, and 175, 30 mg/kg bw) and in females (450 and 30 mg/kg bw/day)
F1-breed period
450, 175, 30 mg/kg bw/day: reduced bw in males
450 mg/kg bw/day females: reduced maternal gestational and lactational body weights

REPRODUCTIVE PERFORMANCE (PARENTAL ANIMALS)
P-generation:
reproductive parameters including gestational length were unaffected by treatment
F1-generation:
reproductive parameters including gestational length were unaffected by treatment

ORGAN WEIGHTS, GROSS PATHOLOGY, HISTOPATHOLOGY (PARENTAL ANIMALS).
all groups:
there were no treatment related gross or histological lesions in P, F1 and F2 rats which survived to scheduled sacrifice animals that died prior scheduled:
P and F1 males: lesions in brain, lungsm thymic regions, decrease in number of sperm in epididymides, atrophied seminal vesicles and coagulation glands, epididymitis
P and F1 females: lesions in brain and lungs
Key result
Dose descriptor:
NOAEL
Remarks:
general toxicity
Effect level:
30 mg/kg bw/day
Based on:
test mat.
Sex:
male/female
Basis for effect level:
other: >= 175 mg/kg bw/d: signs of overt toxicity: hypoactivity, ataxia, twitches, tremors, prostration, urine staining, audible respiration and perioral wetness
Key result
Dose descriptor:
NOAEL
Remarks:
fertility
Effect level:
450 mg/kg bw/day
Based on:
test mat.
Sex:
male/female
Basis for effect level:
other: Effects on reproduction function or on morphology of reproductive tissues were not detected.
Critical effects observed:
not specified
Clinical signs:
effects observed, treatment-related
Dermal irritation (if dermal study):
not examined
Mortality:
mortality observed, treatment-related
Body weight and weight changes:
effects observed, treatment-related
Food consumption and compound intake (if feeding study):
not specified
Food efficiency:
not specified
Water consumption and compound intake (if drinking water study):
not specified
Ophthalmological findings:
not examined
Haematological findings:
not examined
Clinical biochemistry findings:
not examined
Urinalysis findings:
not examined
Behaviour (functional findings):
not examined
Immunological findings:
not examined
Organ weight findings including organ / body weight ratios:
not specified
Gross pathological findings:
no effects observed
Neuropathological findings:
not specified
Histopathological findings: non-neoplastic:
no effects observed
Histopathological findings: neoplastic:
not examined
Other effects:
not specified
Reproductive function: oestrous cycle:
not specified
Reproductive function: sperm measures:
not specified
Reproductive performance:
no effects observed
CLINICAL SIGNS AND MORTALITY (PARENTAL ANIMALS)
P, pre-breed period:
450 mg/kg bw
clinical signs: hypoactivity, ataxia, twitches, tremors, prostration, unkempt appearance (males), urine stains, audible respiration, perinasal encrustration, perioral wetness
mortality 7/25 males; 5/25 females
175 mg/kg bw/day
sacrifice due to trauma of 1/25 male
F1, pre-breed period
450 mg/kg bw/day:clinical signs: hypoactivity, ataxia, twitches, tremors, prostration, unkempt appearance (males), urine stains, audible respiration, perinasal encrustration, perioral wetness(also at 175 mg/kg bw/day)
mortality: 450mg/kg bw/day: 3 males and 4 females
F1 breed period,
mortality during gestation: 1 female in control and 30 and 175 mg/kg bw/day groups and 3 females in the 450 mg/kg bw/day group
mortality during lactation : 3 females at 450 mg/kg bw/day group

BODY WEIGHT (PARENTAL ANIMALS)
P, pre-breed period:
450 mg/kg bw/day, male, female: reduced body weight gain
P, breed period
mortality 450 mg/kg bw 2/20 females; 175 mg/kg bw 1/24 female
F1, pre-breed period:
slightly reduced body weight in males (450, and 175, 30 mg/kg bw) and in females (450 and 30 mg/kg bw/day)
F1-breed period
450, 175, 30 mg/kg bw/day: reduced bw in males
450 mg/kg bw/day females: reduced maternal gestational and lactational body weights

REPRODUCTIVE PERFORMANCE (PARENTAL ANIMALS)
P-generation:
reproductive parameters including gestational length were unaffected by treatment
F1-generation:
reproductive parameters including gestational length were unaffected by treatment

ORGAN WEIGHTS, GROSS PATHOLOGY, HISTOPATHOLOGY (PARENTAL ANIMALS).
all groups:
there were no treatment related gross or histological lesions in P, F1 and F2 rats which survived to scheduled sacrifice animals that died prior scheduled:
P and F1 males: lesions in brain, lungsm thymic regions, decrease in number of sperm in epididymides, atrophied seminal vesicles and coagulation glands, epididymidis
P and F1 females: lesions in brain and lungs
Key result
Dose descriptor:
NOAEL
Remarks:
general toxicity
Effect level:
30 mg/kg bw/day
Based on:
test mat.
Sex:
male/female
Basis for effect level:
other: >= 175 mg/kg bw/d: signs of overt toxicity: hypoactivity, ataxia, twitches, tremors, prostration, urine staining, audible respiration and perioral wetness
Key result
Dose descriptor:
NOAEL
Remarks:
fertility
Effect level:
450 mg/kg bw/day
Based on:
test mat.
Sex:
male/female
Basis for effect level:
other: Effects on reproduction function or on morphology of reproductive tissues were not detected.
Critical effects observed:
not specified
Clinical signs:
effects observed, treatment-related
Dermal irritation (if dermal study):
not examined
Mortality / viability:
mortality observed, treatment-related
Body weight and weight changes:
effects observed, treatment-related
Food consumption and compound intake (if feeding study):
not specified
Food efficiency:
not specified
Water consumption and compound intake (if drinking water study):
not specified
Ophthalmological findings:
not examined
Haematological findings:
not examined
Clinical biochemistry findings:
not examined
Urinalysis findings:
not examined
Sexual maturation:
not specified
Organ weight findings including organ / body weight ratios:
not specified
Gross pathological findings:
no effects observed
Histopathological findings:
no effects observed
Other effects:
not specified
Behaviour (functional findings):
not examined
Developmental immunotoxicity:
not examined
F1 offspring:
litter size, sex ratio, litter viability and pup survival were unaffected by treatment
450 mg/kg bw/day, female: reduced female pup body weight
F2-generation:
litter size andsex ratio were unaffected by treatment
450 mg/kg bw/day lactational index was reduced, pups body weight and body weight gain was reduced and pup deaths increased
Pathology:
all groups:
There were no treatment related gross or histological lesions in F1 and F2 rats which survived to scheduled sacrifice.
Key result
Dose descriptor:
NOAEL
Generation:
F1
Effect level:
175 mg/kg bw/day
Based on:
test mat.
Sex:
male/female
Basis for effect level:
other: In F1 the female pups had reduced body weights in the highest dose tested, but pup survival was not affected. In F2 pup body weight, pup body weight gain and pup lactational index were reduced and pup mortality was increased at the highest dose.
Critical effects observed:
not specified
Clinical signs:
effects observed, treatment-related
Dermal irritation (if dermal study):
not examined
Mortality / viability:
mortality observed, treatment-related
Body weight and weight changes:
effects observed, treatment-related
Food consumption and compound intake (if feeding study):
not specified
Food efficiency:
not specified
Water consumption and compound intake (if drinking water study):
not specified
Ophthalmological findings:
not examined
Haematological findings:
not examined
Clinical biochemistry findings:
not examined
Urinalysis findings:
not examined
Sexual maturation:
not specified
Organ weight findings including organ / body weight ratios:
not specified
Gross pathological findings:
no effects observed
Histopathological findings:
no effects observed
Other effects:
not specified
Behaviour (functional findings):
not examined
Developmental immunotoxicity:
not examined
F1 offspring:
litter size, sex ratio, litter viability and pup survival were unaffected by treatment
450 mg/kg bw/day, female: reduced female pup body weight
F2-generation:
litter size andsex ratio were unaffected by treatment
450 mg/kg bw/day lactational index was reduced, pups body weight and body weight gain was reduced and pup deaths increased
Pathology:
all groups:
There were no treatment related gross or histological lesions in F1 and F2 rats which survived to scheduled sacrifice.
Key result
Dose descriptor:
NOAEL
Generation:
F2
Effect level:
175 mg/kg bw/day
Based on:
test mat.
Sex:
male/female
Basis for effect level:
other: In F1 the female pups had reduced body weights in the highest dose tested, but pup survival was not affected. In F2 pup body weight, pup body weight gain and pup lactational index were reduced and pup mortality was increased at the highest dose.
Critical effects observed:
not specified
Key result
Reproductive effects observed:
no
Conclusions:
Two-generation study according to TSCA Health Effects Test Guideline for specific organ/tissue toxicity - Reproduction/Fertility effects (EPA, 1983):
Effects on reproductive function or on morphology of reproductive tissues were not detected even at doses producing overt toxicity in adult rats (hypoactivity, ataxia, twitches, tremors, prostration,urine stains, audible respiration, and perioral wetness). The NOAEL (fertility) was 450 mg/kg bw/day. The NOAEL (toxicity) was 30 mg/kg bw/d. In F1 and F2 , litter size, sex ratio, and litter viablity was unaffected by treatment. In F1 the female pups had reduced body weights in the highest dose tested, but pup survival was not affected. In F2, pup body weight, pup body weight gain and pup lactational index were reduced and pup mortality was increased at the highest dose. Thus the NOAEL (offspring) was 175 mg/kg bw/d.
Endpoint:
two-generation reproductive toxicity
Type of information:
experimental study
Adequacy of study:
weight of evidence
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study
Qualifier:
according to
Guideline:
other: TSCA Health Effects Test Guideline for specific organ/tissue toxicity - Reproduction/Fertility effects (EPA, 1983)
GLP compliance:
yes
Limit test:
no
Species:
rat
Strain:
Sprague-Dawley
Sex:
male/female
Details on test animals and environmental conditions:
TEST ANIMALS
- Source: Charles River Breeding Laboratories, Kingston, NY
- Age at study initiation: 6 wks (P) ;
- Weight at study initiation: (P) Males: 193-194 g; Females: ca. 151 g;
- Housing: initially 2/same sex during acclimation period; and then singly except for the cohabitation and lactation periods
- Diet: ad libitum
- Water: ad libitum
- Acclimation period: 14 days


ENVIRONMENTAL CONDITIONS
- Temperature: 68-74°F
- Humidity (%): 40-60
- Photoperiod (hrs dark / hrs light): 12/12
Route of administration:
oral: gavage
Vehicle:
corn oil
Details on exposure:
PREPARATION OF DOSING SOLUTIONS:
Dosing formulations were prepared by weighing the amount of test chemical into a volumetric flask and diluting to volume with certified corn oil. The resulting solutions were mixed by repeated inversions and stored at room temperature.
Details on mating procedure:
- M/F ratio per cage: 1/1
- Length of cohabitation: 21 days
- Proof of pregnancy: vaginal plug / sperm in vaginal smear referred to as day 0 of pregnancy
- After 7 days of unsuccessful pairing replacement of first male by another male with proven fertility.
- Further matings after two unsuccessful attempts: no
- After successful mating each pregnant female was caged singly
- Any other deviations from standard protocol: no
Analytical verification of doses or concentrations:
yes
Details on analytical verification of doses or concentrations:
A standard stock solution was prepared (1 mg/mL propanol),which was used to prepare standards ranging fron 10 to 100 ng/µL. With these solutions a standard curve was generated using HPLC. Dosing formulation concentrations were veryfied by preparing aliquots which were injected onto the HPLC column. The measured concentration of each dosing solution was then calculated from the equitation for the standard curve developed by linear regression.
Duration of treatment / exposure:
Exposure period: 27 w
Premating exposure period (males): 10 weeks
Premating exposure period (females): 10 weeks
Frequency of treatment:
once per day , 5 d/w
F1 generation producing F2: once per day, 7 days per week
Details on study schedule:
at day 28-40 post partum F1 animals selected to be parents of the F2 generation were gavaged with their respective formulations for at least 11 weeks 5 days/week.
The F1 animals were approximately 15 to 17 weeks of age at the initiation of the mating period. They were dosed from that time point 7 days/week. Mating procedure was performed as done with the P-generation
Dose / conc.:
30 mg/kg bw/day (actual dose received)
Dose / conc.:
175 mg/kg bw/day (actual dose received)
Dose / conc.:
450 mg/kg bw/day (actual dose received)
No. of animals per sex per dose:
25 animals/sex/group
Control animals:
yes, concurrent vehicle
Details on study design:
no further data
Positive control:
no data
Parental animals: Observations and examinations:
Mortality: twice daily
General conditon: daily throughout the course of the study including skin and fur, eyes and mucous membranes, respiratory symptoms, circulatory system, autonomic and central nervous system, somatomotor activity, behavior pattern
Body weight determination
male, female: initially and weekly until mating
female during gestation: day 0, 7, 13, 20; post partum: day 0, 4, 7, 14, 21
Food consumption
measured weekly during pre-breed dosing period for P and F1 generation; all other phases of this sutdy determination was made visually
Oestrous cyclicity (parental animals):
no data
Sperm parameters (parental animals):
no data
Litter observations:
STANDARDISATION OF LITTERS
- Performed on day 4 postpartum: yes
- If yes, maximum of 8 pups/litter (4 sex/litter as nearly as possible); excess pups were killed and discarded.

PARAMETERS EXAMINED
The following parameters were examined in F1 / F2 offspring:
number and sex of pups, stillbirths, live births, postnatal mortality, presence of gross anomalies, weight gain, physical or behavioural abnormalities

GROSS EXAMINATION OF DEAD PUPS:
yes, for external and internal abnormalities; possible cause of death was not determined for pups born or found dead.
Postmortem examinations (parental animals):
SACRIFICE
- Male animals: All surviving animals after the completion of the mating period
- Maternal animals: All surviving animals after the F1 and F2 litters have been weaned

GROSS NECROPSY
- Gross necropsy consisted of external and internal examinations including the cervical, thoracic, and abdominal viscera.
A complete gross necropsy was conducted for any parental animal dying on test.


HISTOPATHOLOGY
Male and female adult rats of the highest dose groups and the controls
The tissues as indicated below, were prepared for microscopic examination and weighed, respectively:
pituitary, vagina, uterus, ovaries, testes, epididymides, seminal vesicles, prostate and other tissues with gross lesions identified as being potentially treatment-related.
A complete histopathological examination was conducted for any parental animal dying on test.
Postmortem examinations (offspring):
All pups dying during lactation are necropsied to investigate the cause of death.

At weaning, postnatal day 21, 1 female and 1 male from each F1 litter is selected on a random basis to become parents of the next generation.
The remaining offspring is examined for gross external abnormalities, euthanized and discarded.
Statistics:
Levene's test for equal variances, analysis of variance (ANOVA), t-test, Kruskal-Wallis test, Mann-Whitney U test Fisher's exact test
Reproductive indices:
calculated for P and F1 animals:
Mating Index (%):
---for males: number of males impregnating females divided through the total number of males paired multiplied by 100
---for females: number of females with copulation plugs divided through the number of females cohabited multiplied by 100

Fertility Index(%):
---for males: number of males producing pregnant females divided through number of males impregnating females multiplied by 100
---for females: number of pregnant females divided through number of plug-positive females multiplied by 100

Gestational Index (%)
number of females with live litters divided through number of females pregnant multiplied by 100
Offspring viability indices:
calculated for F1 and for F2 animals
live birth index (%)
number of live pups at birth divided through the toal number of pups born multiplied by 100
4-Day Survival Index (%):
number of pups surviving 4 days divided through total number of live pups at birth multiplied by 100
7-Day Survival Index(%):
number of pups surviving 7 days divided through total number of live pups at 4 days multiplied by 100
14- Day Survival Index (%):
number of pups surviving 14 days divided through total number of live pups at 7 days multiplied by 100
21-day survival index (%):
number of pups surviving 21 days divided through total number of live pups at 14 days multiplied by 100
Lactation index (%):
number of pups surviving 21 days divided through total number of live pups at 4 days multiplied by 100
Clinical signs:
effects observed, treatment-related
Mortality:
mortality observed, treatment-related
Body weight and weight changes:
effects observed, treatment-related
Food consumption and compound intake (if feeding study):
not specified
Food efficiency:
not specified
Ophthalmological findings:
not examined
Haematological findings:
not examined
Clinical biochemistry findings:
not examined
Urinalysis findings:
not examined
Behaviour (functional findings):
not examined
Immunological findings:
not examined
Organ weight findings including organ / body weight ratios:
not specified
Gross pathological findings:
not specified
Neuropathological findings:
not specified
Histopathological findings: non-neoplastic:
not specified
Histopathological findings: neoplastic:
not examined
Other effects:
no effects observed
Reproductive function: oestrous cycle:
not specified
Reproductive function: sperm measures:
not specified
Reproductive performance:
no effects observed
F0-generation:
Mortality during pre-breed period:
450 mg/kg bw/d males: 12/25 and females: 8/25
Signs of intoxication: 450 mg/kg bw/d, males and females: hypoactivity, ataxia, twitches, tremors, prostration, gasping, rapid respiration, lacrimation, amd perioral wetness occurred immediately after dosing but did not persist until the next day.
Mean weight gain in F0 males and F0 females were equivalent across the groups
Mean body weight, significantly reduced: males: 175 mg-gr., 450 mg-gr., week 13: 489.9 g,470.9 g versus 522 g of controls
 
Reproductive parameters for F0 parents:
Mating index (males and females), fertility index (males and females) and gestational index were not affected by treatment.
Body weight development during gestation and lactation was equivalent across the groups.
Key result
Dose descriptor:
NOAEL
Remarks:
general toxicity
Effect level:
30 mg/kg bw/day
Based on:
test mat.
Sex:
male/female
Basis for effect level:
other: 450 mg/kg bw: increased mortality; 450 and 175 mg/kg bw/d: signs of intoxication
Key result
Dose descriptor:
NOAEL
Remarks:
fertility
Effect level:
450 mg/kg bw/day
Based on:
test mat.
Sex:
male/female
Basis for effect level:
other: There were no treatment related reproductive effects obseved in this study.
Critical effects observed:
not specified
Clinical signs:
effects observed, treatment-related
Mortality:
mortality observed, treatment-related
Body weight and weight changes:
effects observed, treatment-related
Food consumption and compound intake (if feeding study):
not specified
Food efficiency:
not specified
Ophthalmological findings:
not examined
Haematological findings:
not examined
Clinical biochemistry findings:
not examined
Urinalysis findings:
not examined
Behaviour (functional findings):
not examined
Immunological findings:
not examined
Organ weight findings including organ / body weight ratios:
not specified
Gross pathological findings:
not specified
Neuropathological findings:
not specified
Histopathological findings: non-neoplastic:
not specified
Histopathological findings: neoplastic:
not examined
Other effects:
not specified
Reproductive function: oestrous cycle:
not specified
Reproductive function: sperm measures:
not specified
Reproductive performance:
no effects observed
F1-adult-generation
Signs of intoxication: 450 mg/kg bw/d, males and females: hypoactivity, ataxia, twitches, tremors, prostration, gasping, rapid respiration, lacrimation, and perioral wetness
175 mg/kg bw/d: males: perioral wetness females: hypoactivity, ataxia, perioral wetness
Mortality: 450 mg-group: pre-breed period: 8 males and 14 females additionally: 7 males and 9 females died prior to mating, 3 females which were found pregnant diedand another one died during gestation
body weight and weight development females: equivalent across the groups. Males: week 14, low, mid, high dose: 586.6 g, 564.1 g, 494.4 g vs.526.3 g of controls
 
Reproductive parameters for F1 parents: Mating index (males and females), fertility index (males and females) and gestational index were not affected by treatment.
Body weight development during gestation and lactation was equivalent across the groups.
Key result
Dose descriptor:
NOAEL
Remarks:
general toxicity
Effect level:
30 mg/kg bw/day
Based on:
test mat.
Sex:
male/female
Basis for effect level:
other: 450mg/kg bw: increased mortality; 450 and 175 mg/kg bw/d: signs of intoxication
Key result
Dose descriptor:
NOAEL
Remarks:
fertility
Effect level:
450 mg/kg bw/day
Based on:
test mat.
Sex:
male/female
Basis for effect level:
other: There were no treatment related reproductive effects obseved in this study.
Critical effects observed:
not specified
Clinical signs:
not specified
Dermal irritation (if dermal study):
not examined
Mortality / viability:
mortality observed, treatment-related
Body weight and weight changes:
effects observed, treatment-related
Food consumption and compound intake (if feeding study):
not specified
Food efficiency:
not specified
Water consumption and compound intake (if drinking water study):
not specified
Ophthalmological findings:
not examined
Haematological findings:
not examined
Clinical biochemistry findings:
not examined
Urinalysis findings:
not examined
Sexual maturation:
not specified
Organ weight findings including organ / body weight ratios:
not specified
Gross pathological findings:
not specified
Histopathological findings:
not specified
Other effects:
not specified
Behaviour (functional findings):
not examined
Developmental immunotoxicity:
not examined
F1-pups: Live-birth index was comparable across the groups, sex ratio was not affected
Survival Indices: 4-day-, 7-day-, 14-day- and 21-day-survival indices and lactation index were equivalent across the groups.
450 mg/kg bw/d, males (pre-breed period): significantly reduced mean body weights: 139.6 g versus 162 g in controls
Key result
Dose descriptor:
NOAEL
Generation:
F1
Effect level:
ca. 175 mg/kg bw/day
Based on:
test mat.
Sex:
male/female
Basis for effect level:
other: F1 (males) significantly reduced body weights at 450 mg/kg bw group
Critical effects observed:
not specified
F2-pups:
- Live-birth index was comparable across the groups, sex ratio was not affected
- Survival Indices: 4-day-, 7-day-, 14-day- and 21-day-survival indices were equivalent across the groups.
- Lactation index: 450 mg-group: was significantly reduced (75.5 versus 99.4 in controls)
 
Key result
Dose descriptor:
NOAEL
Generation:
F2
Effect level:
175 mg/kg bw/day
Based on:
test mat.
Sex:
male/female
Basis for effect level:
other: Significantly reduced lactation index in the 450 mg/kg bw group
Critical effects observed:
not specified
Key result
Reproductive effects observed:
no

Conclusion:

The A/D ratio (the dose level at which there were no observable effects in offsprings) is less than 1: (30/175) indicating no increased risk to offspring from o-cresol in the absence of parental effects.

Conclusions:
Two-generation reproductive toxicity according to TSCA Health Effects Test Guideline for specific organ/tissue toxicity - Reproduction/Fertility effects (EPA, 1983)
Continued administration of o-cresol by gavage for two generations to Sprague-Dawley rats resulted in general toxicity including increased mortality at 450 mg/kg bw/d and in clinical signs of toxicity including hypoactivity, ataxia, twitches, tremors, prostration, gasping, rapid respiration and perioral wetness at >= 175 mg/kg bw/d (NOAEL (general toxicity) 30 mg/kg bw/d). No reproductive parameters were affected by treatment in either of the two generations (NOAEL (fertility) 450 mg/kg bw/d).
The NOAEL (offspring) is 175 mg/kg bw/d based on significantly reduced body weights in F1 males and in significantly reduced lactation index in F2 at 450 mg/kg bw.
Endpoint:
screening for reproductive / developmental toxicity
Type of information:
experimental study
Adequacy of study:
weight of evidence
Study period:
26 July 2004 - 17 Sept 2004
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study
Reason / purpose:
reference to same study
Qualifier:
according to
Guideline:
OECD Guideline 422 (Combined Repeated Dose Toxicity Study with the Reproduction / Developmental Toxicity Screening Test)
Deviations:
no
GLP compliance:
yes
Limit test:
no
Species:
rat
Strain:
Sprague-Dawley
Sex:
male/female
Details on test animals and environmental conditions:
Test animals
Age: 9weeks (males and females)
Weight at dosing: 333 - 365 g males; 205 - 237g females
Source: Charles River Laboratory, Raleigh, North Carolina, USA
Acclimatisation: 5 days
Diet: Chow (#5002), ad libitum
Water: Tap water, ad libitum
Housing: F0 generation rats were individually housed except during the cohabitation and postpartum periods. During cohabitation, each pair of rats were housed in the male rat's cage. Each dam and delivered litter was housed in a common nesting box during the postpartum period.
 
Environmental conditions
Temperature: 18 - 26°C
Humidity: 30 - 70%
Photoperiod: Alternating 12-hour light/dark cycles
 
Route of administration:
oral: gavage
Vehicle:
corn oil
Details on mating procedure:
Male and female rats were pair 1:1 and cohabited for a maximum of 14 days. Female rats with spermatozoa observed in a smear of the vaginal contents and/or a copulatory plug in situ were considered to at GD 0 and then individually housed.
Analytical verification of doses or concentrations:
yes
Duration of treatment / exposure:
Minimum of 28 days (14 days of dosing prior to cohabitation).
Frequency of treatment:
Once daily
Dose / conc.:
30 mg/kg bw/day (actual dose received)
Dose / conc.:
100 mg/kg bw/day (actual dose received)
Dose / conc.:
245 mg/kg bw/day (actual dose received)
No. of animals per sex per dose:
10 male and 10 females/group
Parental animals: Observations and examinations:
Observations:
Observed twice daily for mortality and morbidity for all F0 animals. Clinical signs of toxicity were performed weekly. Functional observational battery evaluations were performed once on 5 male and 5 female F0 generation animals.
 
Body weight:
Recorded weekly.
 
Food consumption and compound intake:
Recorded every other day.
 
Haematology & clinical chemistry:
Collected from 5 male and 5 female F0 generation animals at necropsy. Blood samples were collected from the vena cava. The following haematology and clinical chemistry parameters were measured:
Haematology: total leukocyte count, differential leukocyte count (neutrophil, lymphocyte, monocyte, eosinophil, basophil, large unstained cell); RBC indices (mean corpuscular volume, mean corpuscular haemogloblin, mean corpuscular haemoglobin concentration), platelet count, prothombin time and activated partial thromboplastin time.
Clinical chemistry: blood urea nitrogen, alanine aminotransferase activity, aspartate transaminase activity, alkaline phosphatase, glucose, cholesterol, calcium, chloride, phosphorous, potassium, sodium, total protein, albumin, globulin, albumin/globulin ratio, total bilirubin, creatinine, triglycerides.
Litter observations:
Observations:
Observed twice daily for mortality and morbidity for all F1 generation animals.
Postmortem examinations (parental animals):
Sacrifice and pathology:
Gross pathological examination was performed on 5 male and 5 females/group of the F0 generation. An initial examination of external surfaces and all orifices, as well as the cranial, thoracic and abdominal cavities, including contents. The epidodymides, seminal vesicles with coagulating gland and prostate were retained.

Dams with no suriving pups were sacrificed after the last pup was found dead, missing or presumed cannibalised. A gross necropsy of the thoracic, abdominal and pelvic viscera was performed.

Organ weights:
The following organs were weighed from 5 male and 5 females/group of the F0 generation at necropsy:
liver, spleen, kidneys, brain, adrenals, heart, thymus. ovaries, testes, uterus (with cervix) and epidiymides
Postmortem examinations (offspring):
F1 generation pups that died before the initial examination of the litter for pup viability were evaluated for vital status at birth. The lungs were removed and immersed in water. Pups with lungs that sank were considered stillborn; pups with lungs that floated were considered liveborn and to have died shortly after birth. Pups with gross lesions found on days 2 to 4 postpartum were preserved for possible future evaluation. On day 5 postpartum, pups were sacrificed and examined for gross lesions. Necropsy included a single cross-section of the head at the level of the frontal-parietal suture and examination of the cross sectioned brain.
Statistics:
Statistical analysis was limited to body weights and reproductive endpoints. Dunnett's test was used.
All rats survived the treatment. In males, urine stained fur was observed at the 245 mg/kg bw/day level. Body weight gain and food consumption were unaffected by treatment. Neurotoxicity was not observed during the study and there were no treatment related effects observed at gross necropsy or histopathologically. Urine staining of the fur was observed in females at the 245 mg/kg bw/day level.
 
No effect on mating and fertility parameters were observed up to a maximum dose of 245 mg/kg bw/day.
Key result
Dose descriptor:
NOAEL
Remarks:
general toxicity
Effect level:
ca. 100 mg/kg bw/day (actual dose received)
Based on:
test mat.
Sex:
male/female
Basis for effect level:
other: Due to clinical observations (urine-stained fur, increased kidney, liver and ovarian relative weight).
Key result
Dose descriptor:
NOAEL
Remarks:
Reproductive
Effect level:
>= 245 mg/kg bw/day (actual dose received)
Based on:
test mat.
Sex:
male/female
Basis for effect level:
other: No adverse effects noted on reproductive indices observed.
Critical effects observed:
no
F1 animals showed no treatment related clinical or necropsy signs. Haematology, clinical pathology and FOB parameters were unaffected.
Key result
Dose descriptor:
NOAEL
Generation:
F1
Effect level:
>= 245 mg/kg bw/day
Based on:
test mat.
Sex:
male/female
Basis for effect level:
other: no effects observed up to the highest dose
Critical effects observed:
no
Key result
Reproductive effects observed:
no
Conclusions:
The test substance mixed ethylphenol isomers was administered to rats by oral gavage at 0, 30, 100 and 245 mg/kg/day. The general toxicological No Observable Adverse Effect Level was shown to be 100 mg/kg/day.

No effect on reproductive indices, therefore the reproductive NOAEL is considered to be in excess of 245 mg/kg/day.
Endpoint:
screening for reproductive / developmental toxicity
Type of information:
experimental study
Adequacy of study:
weight of evidence
Study period:
26 July 2004 - 17 Sept 2004
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study
Reason / purpose:
reference to same study
Qualifier:
according to
Guideline:
OECD Guideline 422 (Combined Repeated Dose Toxicity Study with the Reproduction / Developmental Toxicity Screening Test)
Deviations:
no
GLP compliance:
yes
Limit test:
no
Species:
rat
Strain:
Sprague-Dawley
Sex:
male/female
Details on test animals and environmental conditions:
Test animals:
Age: 9 weeks (males and females)
Weight at dosing:333 - 365 g males; 205 - 237 g females
Source: Charles River Laboratory, Raleigh, North Carolina, USA
Acclimatisation: 5 days
Diet:Chow (#5002), ad libitum
Water: Tap water ,ad libitum
Housing: F0 generation rats were individually housed except during the cohabitation and postpartum periods. During cohabitation, each pair of rats were housed in the male rat's cage. Each dam and delivered litter was housed in a common nesting box during the postpartum period.
 
Environmental conditions:
Temperature: 18 - 26°C
Humidity: 30 - 70%
Photoperiod: Alternating 12-hour light/dark cycles
Route of administration:
oral: gavage
Vehicle:
corn oil
Details on mating procedure:
Male and female rats were pair 1:1 and cohabited for a maximum of 14 days. Female rats with spermatozoa observed in a smear of the vaginal contents and/or a copulatory plug in situ were considered to at GD 0 and then individually housed.
Analytical verification of doses or concentrations:
yes
Duration of treatment / exposure:
Minimum of 28 days (14 days of dosing prior to cohabitation).
Frequency of treatment:
Once daily
Dose / conc.:
30 mg/kg bw/day (actual dose received)
Dose / conc.:
100 mg/kg bw/day (actual dose received)
Dose / conc.:
245 mg/kg bw/day (actual dose received)
No. of animals per sex per dose:
10 male and 10 females/group
Parental animals: Observations and examinations:
Observations:
Observed twice daily for mortality and morbidity for all F0 animals. Clinical signs of toxicity were performed weekly. Functional observational battery evaluations were performed once on 5 male and 5 female F0 generation animals.
 
Body weight:
Recorded weekly.
 
Food consumption and compound intake:
Recorded every other day.
 
Haematology & clinical chemistry:
Collected from 5 male and 5 female F0 generation animals at necropsy. Blood samples were collected from the vena cava. The following haematology and clinical chemistry parameters were measured:
Haematology: total leukocyte count, differential leukocyte count (neutrophil, lymphocyte, monocyte, eosinophil, basophil, large unstained cell); RBC indices (mean corpuscular volume, mean corpuscular haemogloblin, mean corpuscular haemoglobin concentration), platelet count, prothombin time and activated partial thromboplastin time.
Clinical chemistry: blood urea nitrogen, alanine aminotransferase activity, aspartate transaminase activity, alkaline phosphatase, glucose, cholesterol, calcium, chloride, phosphorous, potassium, sodium, total protein, albumin, globulin, albumin/globulin ratio, total bilirubin, creatinine, triglycerides.
Litter observations:
Observations:
Observed twice daily for mortality and morbidity for all F1 generation animals.
Postmortem examinations (parental animals):
Sacrifice and pathology:
Gross pathological examination was performed on 5 male and 5 females/group of the F0 generation. An initial examination of external surfaces and all orifices, as well as the cranial, thoracic and abdominal cavities, including contents. The epidodymides, seminal vesicles with coagulating gland and prostate were retained.

Dams with no suriving pups were sacrificed after the last pup was found dead, missing or presumed cannibalised. A gross necropsy of the thoracic, abdominal and pelvic viscera was performed.

Organ weights:
The following organs were weighed from 5 male and 5 females/group of the F0 generation at necropsy:
liver, spleen, kidneys, brain, adrenals, heart, thymus. ovaries, testes, uterus (with cervix) and epidiymides.
Postmortem examinations (offspring):
F1 generation pups that died before the initial examination of the litter for pup viability were evaluated for vital status at birth. The lungs were removed and immersed in water. Pups with lungs that sank were considered stillborn; pups with lungs that floated were considered liveborn and to have died shortly after birth. Pups with gross lesions found on days 2 to 4 postpartum were preserved for possible future evaluation. On day 5 postpartum, pups were sacrificed and examined for gross lesions. Necropsy included a single cross-section of the head at the level of the frontal-parietal suture and examination of the cross sectioned brain.
Statistics:
Statistical analysis was limited to body weights and reproductive endpoints. Dunnett's test was used.
Food efficiency:
not specified
All rats survived the treatment. In males, urine stained fur was observed at the 245 mg/kg/day level. Body weight gain and food consumption were unaffected by treatment. Mating frequency was reduced at the 245 mg/kg bw/day level. Neurotoxicity was not observed during the study and there were no treatment related effects observed at gross necropsy or histopathologically. Urine staining of the fur was observed in females at the 245 mg/kg bw/day level.

Relative weights of the kidney, liver and ovaries were observed to be increased in the 245 mg/kg/day treatment group,
Decreased mating and fertility indices were reported at the highest dose level (245 mg/kg bw) in the combined repeated dose toxicity and reproduction/developmental toxicity screening test. The number of female rats that mated was reduced from 100% in the control group (10/10) to 80% at 245 mg/kg bw (8/10) but the difference was not significantly different. The historical control value was reported as 97.6% over the period 1992-2002 but as no range was given this figure was of limited value. Following a request to Argus addition historical control data were provided on 19 April 2010. The information provided showed fertility data for individual years from 1992 to 1997 giving the range as well as the mean values and these are shown in Table 1.
It is clear from the historical control data that fertility in the mixed xylenols study was within the historical control range in several years during the period from 1992-1997 which corresponds to the time when the mixed xylenols study was conducted.

As the reduced fertility at 245 mg/kg bw was not statistically significant and was within the historical control range, this effect is considered not to be related to treatment and the NOAEL for reproductive effects in this study should be ≥ 245 mg/kg bw.
Key result
Dose descriptor:
NOAEL
Remarks:
general toxicity
Effect level:
ca. 100 mg/kg bw/day (actual dose received)
Based on:
test mat.
Sex:
male/female
Basis for effect level:
other: Due to clinical observations (urine-stained fur, increased kidney, liver and ovarian relative weight).
Key result
Dose descriptor:
NOAEL
Remarks:
Reproductive
Effect level:
>= 245 mg/kg bw/day (actual dose received)
Based on:
test mat.
Sex:
male/female
Basis for effect level:
other: Whilst a reduced mating frequency was observed, this was within the laboratory's historical control range, therefore not considered biologically relevant.
Critical effects observed:
not specified
F1 animals showed no treatment related clinical or necropsy signs. Haematology, clinical pathology and FOB parameters were unaffected.
 
Key result
Dose descriptor:
NOAEL
Generation:
F1
Effect level:
>= 245 mg/kg bw/day
Based on:
test mat.
Sex:
male/female
Basis for effect level:
other: no effects observed up to highest dose
Critical effects observed:
no
Key result
Reproductive effects observed:
no

Table 1: Fertility index for studies conducted in Crl:CD(SD) Rats

Year

Average

Minimum

Maximum

No of studies

1992

94.1

80.0

100.0

4

1993

89.5

80.0

100.0

9

1994

90.5

66.7

100.0

17

1995

93.8

89.7

100.0

5

1996

93.1

84.0

100.0

13

1997

91.7

71.4

100.0

23

1992 - 1997

91.7

66.7

100.0

71

 

Conclusions:
The test substance mixed xylenol isomers was administered to rats by oral gavage at 0, 30, 100 and 245 mg/kg/day. The general toxicological No Observable Adverse Effect Level was shown to be 100 mg/kg bw/day.

The SD determined that the reproductive NOAEL was found to be 245 mg/kg bw/day due to reduced mating at 245 mg/kg/day, however following request of the historical control data from the laboratory, the reduction in mating frequency to 80% was within the laboratory's historical vehicle control data for this period.

Therefore the reproductive NOAEL is considered to be in excess of 245 mg/kg bw/day.
Endpoint:
two-generation reproductive toxicity
Type of information:
read-across from supporting substance (structural analogue or surrogate)
Remarks:
Summary of available data used for the endpoint assessment of the target substance
Adequacy of study:
key study
Justification for type of information:
refer to analogue justification provided in IUCLID section 13
Reason / purpose:
read-across source
Reason / purpose:
read-across source
Reason / purpose:
read-across source
Key result
Dose descriptor:
NOAEL
Remarks:
general toxicity, rat
Effect level:
30 mg/kg bw/day
Based on:
test mat.
Sex:
male/female
Basis for effect level:
other: 450 mg/kg bw: increased mortality; 450 and 175 mg/kg bw/d: signs of intoxication
Remarks on result:
other: Source, CAS 95-48-7, o-cresol / CAS106-44-5, p-cresol / CAS 108-34-9, m-cresol; CMA, 1989
Key result
Dose descriptor:
NOAEL
Remarks:
fertility, rat
Effect level:
450 mg/kg bw/day
Based on:
test mat.
Sex:
male/female
Basis for effect level:
other: There were no treatment related reproductive effects obseved in this study.
Remarks on result:
other: Source, CAS 95-48-7, o-cresol / CAS106-44-5, p-cresol / CAS 108-34-9, m-cresol; CMA, 1989
Critical effects observed:
not specified
Key result
Dose descriptor:
NOAEL
Remarks:
general toxicity, rat
Effect level:
30 mg/kg bw/day
Based on:
test mat.
Sex:
male/female
Basis for effect level:
other: 450 mg/kg bw: increased mortality; 450 and 175 mg/kg bw/d: signs of intoxication
Remarks on result:
other: Source, CAS 95-48-7, o-cresol / CAS106-44-5, p-cresol / CAS 108-34-9, m-cresol; CMA, 1989
Key result
Dose descriptor:
NOAEL
Remarks:
fertility, rat
Effect level:
450 mg/kg bw/day
Based on:
test mat.
Sex:
male/female
Basis for effect level:
other: There were no treatment related reproductive effects obseved in this study.
Remarks on result:
other: Source, CAS 95-48-7, o-cresol / CAS106-44-5, p-cresol / CAS 108-34-9, m-cresol; CMA, 1989
Critical effects observed:
not specified
Key result
Dose descriptor:
NOAEL
Remarks:
rat
Generation:
F1
Effect level:
ca. 175 mg/kg bw/day
Based on:
test mat.
Sex:
male/female
Basis for effect level:
other: 450 mg/kg bw: o-cr.: F1 (males) reduced bw; p-cr.: toxic effects in the F2 litters / no clear evidence of toxic effects in F1 pups; m-cr.: F1 (females) reduced bw; F2 pups reduced bw, pup bw gain and pup lactational index, increased pup mortality
Remarks on result:
other: Source, CAS 95-48-7, o-cresol / CAS106-44-5, p-cresol / CAS 108-34-9, m-cresol; CMA, 1989
Critical effects observed:
not specified
Key result
Dose descriptor:
NOAEL
Remarks:
rat
Generation:
F2
Effect level:
175 mg/kg bw/day
Based on:
test mat.
Sex:
male/female
Basis for effect level:
other: 450 mg/kg bw: o-cr.: reduced lactation index; p-cr.: toxic effects in F2 litters/no clear evidence of toxic effects in F1 pups; m-cr.: F1(females) reduced bw; F2 pups reduced bw, pup bw gain and pup lactational index, increased pup mortality
Remarks on result:
other: Source, CAS 95-48-7, o-cresol / CAS106-44-5, p-cresol / CAS 108-34-9, m-cresol; CMA, 1989
Critical effects observed:
not specified
Key result
Reproductive effects observed:
no
Conclusions:
Two-generation studies with each of the source substances o-, p- and m-cresol are available. Continued administration of the source substances by gavage for two generations to Sprague-Dawley rats resulted in general toxicity including increased mortality at 450 mg/kg bw/day and in clinical signs of toxicity resulting in a NOAEL (general toxicity) of 30 mg/kg bw/day. No reproductive parameters were affected by treatment in either of the two generations resulting in a NOAEL (fertility) of 450 mg/kg bw/day. The NOAEL (offspring) is 175 mg/kg bw/day based on significant toxic effects in F1 and F2 animals at 450 mg/kg bw/day. A read-across approach can be used with comparable NOAEL values expected to be obtained for the target substance.
Executive summary:

For the three cresol isomers two-generation studies in rats showed that the general toxicity was dominating over the reproductive toxicity as a NOAEL of 30 mg/kg bw/day for general toxicity was derived. No reproductive parameters were affected by the treatment in either of the two generations resulting in a NOAEL of 450 mg/kg bw/day for fertility. The offsprings (F1 and F2) showed toxic effects mainly regarding clinical signs, body weight and lacation index leading to a NOAEL of 175 mg/kg bw/day. Whilst no studies on toxicity to reproduction have been conducted with xylenols or ethylphenols, the experimental data available on cresols are considered to be suitable and meaningful to predict toxicity to reproduction (fertility) of the target substance.

Endpoint:
screening for reproductive / developmental toxicity
Type of information:
read-across from supporting substance (structural analogue or surrogate)
Remarks:
Summary of available data used for the endpoint assessment of the target substance
Adequacy of study:
key study
Justification for type of information:
refer to analogue justification provided in IUCLID section 13
Reason / purpose:
read-across source
Reason / purpose:
read-across source
In the result table below the most critical and relevant value of the weight of evidence approach is given. In the following, the results are shown for the other source substance of this weight of evidence approach:
Source mixed ethyl phenols: NOAEL (general toxicity, rat) ca. 100 mg/kg bw/day (due to clinical observations (urine-stained fur, increased kidney, liver and ovarian relative weight)), NOAEL (reproduction, rat) >= 245 mg/kg bw/day (no adverse effects noted on reproductive indices observed); Merisol, 2005
Key result
Dose descriptor:
NOAEL
Remarks:
general toxicity, rat
Effect level:
ca. 100 mg/kg bw/day (actual dose received)
Based on:
test mat.
Sex:
male/female
Basis for effect level:
other: Due to clinical observations (urine-stained fur, increased kidney, liver and ovarian relative weight).
Remarks on result:
other: Source,mixed xylenols, Merisol, 2005
Key result
Dose descriptor:
NOAEL
Remarks:
Reproductive, rat
Effect level:
>= 245 mg/kg bw/day (actual dose received)
Based on:
test mat.
Sex:
male/female
Basis for effect level:
other: Whilst a reduced mating frequency was observed, this was within the laboratory's historical control range, therefore not considered biologically relevant.
Remarks on result:
other: Source,mixed xylenols, Merisol, 2005
In the result table below the most critical and relevant value of the weight of evidence approach is given. In the following, the results are shown for the other source substance of this weight of evidence approach:
Source mixed ethyl phenols: NOAEL (F1, rat) >= 245 mg/kg bw/day (no effects observed up to highest dose); Merisol, 2005
Key result
Dose descriptor:
NOAEL
Remarks:
rat
Generation:
F1
Effect level:
>= 245 mg/kg bw/day
Based on:
test mat.
Sex:
male/female
Basis for effect level:
other: no effects observed up to highest dose
Remarks on result:
other: Source: mixed xylenols, Merisol, 2005
Critical effects observed:
no
Key result
Reproductive effects observed:
no
Conclusions:
Combined repeated dose toxicity studies with the reproduction/developmental toxicity screening with each of the source substances mixed xylenols and mixed ethylphenols are available in rats. Treatment with the source substances resulted in a NOAEL of 100 mg/kg bw/day for general toxicity as toxic effects were observed at the highest dose. No relevant reproductive or developmental effects were observed. Therefore, a NOAEL of 245 mg/kg bw/day was derived for reproduction and developmental effects.
Executive summary:

For the two source substances, mixed xylenols and mixed ethylphenols, combined repeated dose toxicity studies with the reproduction/developmental toxicity screening in rats showed that general toxicity was dominating over the reproductive/developmental toxicity, a NOAEL of 100 mg/kg bw/day for general toxicity was derived. No reproductive or developmental parameters were affected by the treatment in either the parental or offspring animals resulting in a NOAEL of 245 mg/kg bw/day for reproduction and development. Whilst no studies on toxicity to reproduction have been conducted with tar acid, xylenol fraction, the experimental data available on the source substances are considered to be suitable and meaningful to predict toxicity to reproduction (fertility) of the target substance.

Effect on fertility: via oral route
Endpoint conclusion:
no adverse effect observed
Dose descriptor:
NOAEL
450 mg/kg bw/day
Study duration:
chronic
Species:
rat
Quality of whole database:
The available information comprises adequate, reliable (Klimisch score 1) studies from surrogate substances, i.e. constituents of the target substance. Read-across is justified based on data on the constituents of Tar acids, xylenol fraction (CAS 84989-06-0) (refer to endpoint discussion for further details). Taken together, the information from these independent sources is consistent and provides sufficient weight of evidence for hazard assessment leading to an endpoint conclusion in accordance with Annex XI, 1.2, of Regulation (EC) No 1907/2006. Therefore, the available information as a whole is sufficient to fulfil the standard information requirements set out in Annex IX, 8.7, in accordance with Annex XI, 1.5, of Regulation (EC) No 1907/2006.
Effect on fertility: via inhalation route
Endpoint conclusion:
no study available
Effect on fertility: via dermal route
Endpoint conclusion:
no study available
Additional information

Justification for read-across

There are no experimental data for effects on fertility available for Tar acids, Xylenol fraction (CAS 84989-06-0). In order to fulfil the standard data requirements defined in Regulation (EC) No 1907/2006, Annex IX, 8.7, read-across from appropriate substances is conducted in accordance with Regulation (EC) No 1907/2006, Annex XI, 1.5.

According to Article 13 (1) of Regulation (EC) No 1907/2006, "information on intrinsic properties of substances may be generated by means other than tests, provided that the conditions set out in Annex XI are met”. In particular for human toxicity, information shall be generated whenever possible by means other than vertebrate animal tests, which includes the use of information from structurally related substances (grouping or read-across) “to avoid the need to test every substance for every endpoint”.

Tar acids, Xylenol fraction (CAS 84989-06-0) is an UVCB substance comprised of the main constituents xylenols (all isomers in total > 60%; 2,4- and 2,5-xylenol > 40%), ethyl phenols (< 30%) and cresols (< 25%). The read-across approach is therefore based on the main constituents of Tar acids, Xylenol fraction (CAS 84989-06-0), given common functional groups, common precursors and the likelihood of common breakdown products via biological processes. For further details on the read-across approach, please refer to the analogue justification in section 13 of the technical dossier.

For the evaluation of the effects on fertility read-across from reliable data on the analogue substances mixed xylenols, mixed ethyl phenols as well as to the cresol isomers (m- (CAS 108-39-4), p- (CAS 106-44 5) and o-cresol (CAS 95-48-7)) was conducted in order to fulfill the requirements defined in Regulation (EC) No 1907/2006, Annex IX, 8.7.

Two-generation studies:

o-cresol

A two-generation study according to TSCA Health Effects Test Guideline for specific organ/tissue toxicity - Reproduction/Fertility effects in rats with o-cresol is available (CMA, 1989c). o-cresol was continuously administered by gavage to Sprague-Dawley rats for two generations at doses of 30, 175 and 450 mg/kg bw/day and resulted in general toxicity including increased mortality at 450 mg/kg bw/day and in clinical signs of toxicity including hypoactivity, ataxia, twitches, tremors, prostration, gasping, rapid respiration and perioral wetness. Perioral wetness was also observed at 175 mg/kg bw/day. Thus, the NOAEL for general toxicity was set to 30 mg/kg bw/day. No reproductive parameters were affected by treatment in either of the two generations. Therefore, a NOAEL for fertility of 450 mg/kg bw/day was derived. The NOAEL (offspring = developmental toxicity) is 175 mg/kg bw/day based on significantly reduced body weights in F1 males and in significantly reduced lactation index in F2 at 450 mg/kg bw/day.

Additionally, in a sub-chronic toxicity study with rats and mice reproductive parameters were examined (NTP, 1992). Sperm motility and concentration in males and length of oestrus cycle and vaginal cytology was determined. No adverse effects were observed regarding reproductive parameters in rats and mice of both sexes.

m-cresol

A two-generation study according to TSCA Health Effects Test Guideline for specific organ/tissue toxicity - Reproduction/Fertility effects in rats with m-cresol is available (CMA, 1989d). m-cresol was continuously administered by gavage to Sprague-Dawley rats for two generations at doses of 30, 175 and 450 mg/kg bw/day and resulted in general toxicity including increased mortality at 450 mg/kg bw/day and in clinical signs of toxicity including hypoactivity, ataxia, twitches, tremors, prostration, unkempt appearance (males), urine stains, audible respiration, perinasal encrustration, and perioral wetness. Perioral wetness was also observed at 175 mg/kg bw/day. Thus, the NOAEL for general toxicity was set to 30 mg/kg bw/day. Effects on reproductive function or on morphology of reproductive tissues were not detected even at doses producing overt toxicity in adult rats. The NOAEL (fertility) was 450 mg/kg bw/day. In F1 and F2 , litter size, sex ratio, and litter viablity was unaffected by treatment. In F1 the female pups had reduced body weights in the highest dose tested, but pup survival was not affected. In F2, pup body weight, pup body weight gain and pup lactational index were reduced and pup mortality was increased at the highest dose. Thus the NOAEL (offspring/developmental) was 175 mg/kg bw/day.

p-cresol

A two-generation study according to TSCA Health Effects Test Guideline for specific organ/tissue toxicity - Reproduction/Fertility effects in rats with p-cresol is available (CMA, 1989e). p-cresol was continuously administered by gavage to Sprague-Dawley rats for two generations at doses of 30, 175 and 450 mg/kg bw/day and resulted in general toxicity including increased mortality at 450 mg/kg bw/day and in clinical signs of toxicity including hypoactivity, ataxia, twitches, tremors, prostration, urine stains, audible respiration and perioral wetness starting from 175 mg/kg bw/day. Thus, the NOAEL for general toxicity was set to 30 mg/kg bw/day. Effects on reproductive function or on morphology of reproductive tissues were not detected even at doses producing overt toxicity in adult rats. The NOAEL (fertility) was 450 mg/kg bw/day. The NOAEL(offspring/developmental toxicity) is 175 mg/kg bw/day due to toxic effects in the F2 litters of the high dose group animals and no clear evidence of toxic effects in F1 pups.

Mixed xylenols

A combined repeated dose toxicity study with the reproduction/developmental toxicity screening according to OECD 422 in rats is available with mixed xylenols (Merisol, 2005c). Mixed xylenol was administered to rats by oral gavage at 0, 30, 100 and 245 mg/kg bw/day. As described under repeated dose toxicity the NOAEL for general toxicity was 100 mg/kg bw/day. Decreased mating and fertility indices were reported at the highest dose level (245 mg/kg bw/day). The number of female rats that mated was reduced from 100% in the control group (10/10) to 80% at 245 mg/kg bw/day (8/10) but the difference was not significantly different. It is clear from the historical control data that fertility in the mixed xylenols study was within the historical control range in several years during the period from 1992-1997 which corresponds to the time when the mixed xylenols study was conducted. As the reduced fertility at 245 mg/kg bw/day was not statistically significant and was within the historical control range, this effect is considered not to be related to treatment and the NOAEL for reproductive effects in this study should therefore be ≥ 245 mg/kg bw/day.

Mixed ethylphenols

A combined repeated dose toxicity study with the reproduction/developmental toxicity screening according to OECD 422 in rats is available with mixed ethylphenols (Merisol, 2005c). Mixed ethylpenols was administered to rats by oral gavage at 0, 30, 100 and 245 mg/kg bw/day. As described under repeated dose toxicity the NOAEL for general toxicity was 100 mg/kg bw/day. No effects on mating and fertility parameters were observed up to a maximum dose of 245 mg/kg bw/day thus leading to a NOAEL for reproductive effects of ≥ 245 mg/kg bw/day.

Conclusion:

The parental NOAEL in the multigeneration studies is 30 mg/kg bw/ day. The parental NOAEL in the multigeneration study of all three isomers is based on observations of perioral wetness at 175 mg/kg bw/day. There was also a possible increase in still births at this dose level but there was no clear dose response suggesting that it was not treatment related. As the clinical signs of toxicity were mild and there was a considerable spacing between the NOAEL (30 mg/kg bw/day) and the LOAEL (175 mg/kg bw/day) it is likely that the true NOAEL for this study is at least 50 mg/kg bw/day which is the overall NOAEL for xylenols used for risk assessment. No toxicity in regards to fertility was observed in either the two-generation studies or the screening studies thus showing that the source substances do not provide a potential for effects on fertility even though parental toxicity exists. However, as there are no experimental data available for effects on fertility for Tar acids, Xylenol fraction (CAS 84989-06-0) a weight-of-evidence approach was conducted taking into account all available data on the source substances; Tar acids, Xylenol fraction (CAS 84989-06-0) was therefore not considered to be toxic to reproduction.

Effects on developmental toxicity

Description of key information

In absence of experimental data on Tar acids, Xylenol fraction (CAS 84989-06-0) an analogue read-across approach was conducted:

WoE - o-cresol (RL1; according to TSCA Health Effect Guidelines for Specific Organ/Tissue Toxicity - Developmental Toxicity (EPA 1984, 1987) and GLP, rat): NOAEL (maternal toxicity): 175 mg/kg bw/day; NOEL(developmental toxicity): 175 mg/kg bw/day, NOAEL(developmental toxicity): 450 mg/kg bw/day

WoE - o-cresol (RL1; according to TSCA Health Effect Guidelines for Specific Organ/Tissue Toxicity - Developmental Toxicity (EPA 1984, 1987) and GLP, rabbit): NOAEL (maternal toxicity): 5 mg/kg bw/day; NOEL(developmental toxicity): 50 mg/kg bw/day, NOAEL(developmental toxicity): 100 mg/kg bw/day

WoE - p-cresol (RL1; according to TSCA Health Effect Guidelines for Specific Organ/Tissue Toxicity - Developmental Toxicity (EPA 1984, 1987) and GLP, rat): NOAEL (maternal toxicity): 175 mg/kg bw/day; NOEL(developmental toxicity): 175 mg/kg bw/day, NOAEL(developmental toxicity): 450 mg/kg bw/day

WoE - p-cresol (RL1; according to TSCA Health Effect Guidelines for Specific Organ/Tissue Toxicity - Developmental Toxicity (EPA 1984, 1987) and GLP, rabbit): NOAEL (maternal toxicity): 5 mg/kg bw/day; NOAEL(developmental toxicity): 100 mg/kg bw/day

WoE - m-cresol (RL1; according to TSCA Health Effect Guidelines for Specific Organ/Tissue Toxicity - Developmental Toxicity (EPA 1984, 1987) and GLP, rat): NOAEL (maternal toxicity): 175 mg/kg bw/day; NOAEL(developmental toxicity): 450 mg/kg bw/day

WoE - m-cresol (RL1; according to TSCA Health Effect Guidelines for Specific Organ/Tissue Toxicity - Developmental Toxicity (EPA 1984, 1987) and GLP, rabbit): NOAEL (maternal toxicity): 5 mg/kg bw/day; NOAEL(developmental toxicity): 100 mg/kg bw/day

Link to relevant study records

Referenceopen allclose all

Endpoint:
developmental toxicity
Type of information:
experimental study
Adequacy of study:
weight of evidence
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study
Qualifier:
according to
Guideline:
other: TSCA Health Effects Test guidelines for Specific Organ/Tissue Toxicity - Developmental Toxicity (EPA, 1984, 1987)
Deviations:
no
GLP compliance:
yes
Limit test:
no
Species:
rabbit
Strain:
New Zealand White
Details on test animals and environmental conditions:
TEST ANIMALS
- Source: Hazleton-Dutchland Laboratories, Inc., Denver, PA, USA
- Age at study initiation: 5.5 months
- Weight at study initiation: 2.5 kg
- Housing: singly
- Diet: ad libitum
- Water: ad libitum
- Acclimation period: 2 weeks


ENVIRONMENTAL CONDITIONS
- Temperature (°F ): 72
- Humidity (%): 40-60
- Photoperiod (hrs dark / hrs light) 12/12
Route of administration:
oral: gavage
Vehicle:
corn oil
Details on exposure:
PREPARATION OF DOSING SOLUTIONS:
Dosing formulations were prepared by weighing the amount of test chemical into a volumetric flask and diluting to volume with certified corn oil. The resulting solutions were mixed by repeated inversions and stored at room temperature.
Analytical verification of doses or concentrations:
yes
Details on analytical verification of doses or concentrations:
A standard stock solution was prepared as needed by weighing 50 mg p-cresol into a 50 mL volumetric flask and diluting to volume with propanol. Standards ranging from 10 to 100 ng/mL were prepared by diluting the stock solution with propanol. 10 µL of each standard was injected onto the HPLC. The actual concentration of each dosing solution was calculated from the equitation for the standard curve developed by linear regression.
Details on mating procedure:
- Impregnation procedure: cohoused
- If cohoused:
- M/F ratio per cage: 1:1
- Verification of same strain and source of both sexes: yes
- Proof of pregnancy: vaginal plug referred to as day 0 of pregnancy
Duration of treatment / exposure:
day 6 - 18 of gestation
Frequency of treatment:
once daily
Duration of test:
until gd 29
Dose / conc.:
5 mg/kg bw/day
Dose / conc.:
50 mg/kg bw/day
Dose / conc.:
100 mg/kg bw/day
Control animals:
yes, concurrent vehicle
Details on study design:
no further details
Maternal examinations:
CAGE SIDE OBSERVATIONS: Yes
- Time schedule: daily

DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule: twice daily

BODY WEIGHT: Yes
- Time schedule for examinations: gd 0, 6, 12, 18, 24, 29

FOOD CONSUMPTION: Yes

WATER CONSUMPTION: No

POST-MORTEM EXAMINATIONS: Yes
- Sacrifice on gestation day 29
- Organs examined: stomach gland, liver, gall bladder, kidneys, uterus
Ovaries and uterine content:
The ovaries and uterine content was examined after termination: Yes
Examinations included:
- Gravid uterus weight: Yes
- Number of corpora lutea: Yes
- Number of implantations: Yes
- Number of early resorptions: Yes
- Number of late resorptions: Yes
Fetal examinations:
- Determination of number of fetuses alive: yes
- Detrmination of number of dead fetuses: yes
- Determination of sex ratio: yes
- External examinations: Yes, all per litter
- Soft tissue examinations: Yes, all per litter
- Skeletal examinations: Yes, all per litter
- Head examinations: Yes, half per litter
Statistics:
Levene's test, ANOVA with bonferroni prohability, t-test, Kruskal-Wallis test, Mann-Whithey U-test, Fisher's exact test
Indices:
no data
Historical control data:
no data
Clinical signs:
effects observed, treatment-related
Mortality:
mortality observed, treatment-related
Body weight and weight changes:
no effects observed
Food consumption and compound intake (if feeding study):
no effects observed
Food efficiency:
not specified
Ophthalmological findings:
not examined
Haematological findings:
not examined
Clinical biochemistry findings:
not examined
Urinalysis findings:
not examined
Behaviour (functional findings):
not examined
Immunological findings:
not examined
Organ weight findings including organ / body weight ratios:
no effects observed
Gross pathological findings:
no effects observed
Neuropathological findings:
not examined
Histopathological findings: non-neoplastic:
not specified
Histopathological findings: neoplastic:
not examined
Other effects:
not specified
Number of abortions:
effects observed, non-treatment-related
Pre- and post-implantation loss:
no effects observed
Total litter losses by resorption:
no effects observed
Early or late resorptions:
no effects observed
Dead fetuses:
no effects observed
Changes in pregnancy duration:
no effects observed
Description (incidence and severity):
Migrated Data from removed field(s)
Field "Effects on pregnancy duration" (Path: ENDPOINT_STUDY_RECORD.DevelopmentalToxicityTeratogenicity.ResultsAndDiscussion.ResultsMaternalAnimals.MaternalDevelopmentalToxicity.EffectsOnPregnancyDuration): no effects observed
Changes in number of pregnant:
no effects observed
Other effects:
not specified
Details on maternal toxic effects:
mortality: 100 mg/kg bw: 5/14; 50 mg/kg bw: 2/14; all were pregnant; 1 control female aborted and one each at 5.0 and 50 mg/kg bw was removed due to dosing error, gestational weights and weight changes were not stat. significant different among groups for periodic body weights or weight changes.
50 and 100 mg/kg bw:
clinical signs: included hypoactivity, gasping, cyanosis, laboured rapid and audible respiration and ocular discharge
food consumption: no significant differences among groups for any timeperiod measured; 
no treatment related gross lesions at necropsy of does
maternal organ weights: no significant difference among the groups: terminal bw., gravid uterine weight, corrected bw. or weight change, absolute and relative liver weight
gestational parameters: no significant difference for number of ovarian corpora lutea, number of  implantations sites including total, nonviable (early or late resorptions  or dead fetuses) or viable percent live fetuses per  litter or fetal body  weight per litter; sex ratio was significantly increased (more males) at  50 mg/kg bw but not at 100 mg/kg bw (considered due to  biological  variabilty)

Key result
Dose descriptor:
NOAEL
Effect level:
5 mg/kg bw/day
Based on:
test mat.
Basis for effect level:
other: >= 50 mg/kg bw/d: clinical signs of toxicity included gasping, cyanosis, audible labored and rapid respiration in additon to increased maternal mortality.
Key result
Abnormalities:
no effects observed
Fetal body weight changes:
no effects observed
Description (incidence and severity):
Migrated Data from removed field(s)
Field "Fetal/pup body weight changes" (Path: ENDPOINT_STUDY_RECORD.DevelopmentalToxicityTeratogenicity.ResultsAndDiscussion.ResultsFetuses.FetalPupBodyWeightChanges): no effects observed
Reduction in number of live offspring:
no effects observed
Changes in sex ratio:
effects observed, non-treatment-related
Changes in litter size and weights:
no effects observed
Changes in postnatal survival:
no effects observed
External malformations:
no effects observed
Skeletal malformations:
no effects observed
Visceral malformations:
no effects observed
Other effects:
not specified
Details on embryotoxic / teratogenic effects:
fetal evaluation:
No significant differences among groups for any individual malformations, malformations by category or total malformations; no treatment-related significant differences for any individual external variations, variations by category or total variations.
Key result
Dose descriptor:
NOAEL
Effect level:
100 mg/kg bw/day
Based on:
test mat.
Sex:
male/female
Basis for effect level:
other: No indications of developmental toxicity up to the highest dose tested.
Key result
Abnormalities:
no effects observed
Key result
Developmental effects observed:
no
Conclusions:
Developmental toxicity study according to TSCA Health Effects Test guidelines for Specific Organ/Tissue Toxicity - Developmental Toxicity (EPA, 1984, 1987):
Administration of p-cresol by gavage to time-pregnant New Zealand White rabbits during organogenesis at 0.0, 5.0, 50.0 or 100 mg/kg bw/day resulted in maternal toxicity at 50.0 and 100.0 mg/kg bw/d including mortality and clinical signs of toxicity. No indications of developmental toxicity were observed. Thus, the NOAEL (maternal toxicity) is 5 mg/kg bw/d and the NOAEL for developmental toxicity is 100 mg/kg bw/d.
Endpoint:
developmental toxicity
Type of information:
experimental study
Adequacy of study:
weight of evidence
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study
Qualifier:
according to
Guideline:
other: TSCA Health Effects Test guidelines for Specific Organ/Tissue Toxicity - Developmental Toxicity (EPA, 1984,1987)
GLP compliance:
yes
Limit test:
no
Species:
rat
Strain:
Sprague-Dawley
Details on test animals and environmental conditions:
TEST ANIMALS
- Source: Charles River Breeding Laboratories, Kingston, NY, USA
- Age at study initiation: 56 days at arrival
- Weight at study initiation: 226-230 at gd 0
- Housing: after mating singly
- Diet: ad libitum
- Water: ad libitum
- Acclimation period: 2 weeks


ENVIRONMENTAL CONDITIONS
- Temperature (°F): 72
- Humidity (%): 40-60
- Photoperiod (hrs dark / hrs light): 12/12

Route of administration:
oral: gavage
Vehicle:
corn oil
Details on exposure:
PREPARATION OF DOSING SOLUTIONS:
Dosing formulations were prepared by weighing the amount of test chemical into volumetric flask and diluting to volume with certified corn oil. The resulting solutions were mixed by repeated inversions and stored at room temperature.
Analytical verification of doses or concentrations:
yes
Details on analytical verification of doses or concentrations:
A standard stock solution (1 mg/mL) was prepared as needed by weighing 50 mg p-cresol into a 50 mL flask and diluting to volume with propanol. Standards ranging from 10 to 100 ng/mL were prepared by diluting the stock solution with propanol. 10 µL of each standard was injected onto the HPLC. The actual concentration of each dosing solution was calculated from the equitationfor the standard curve developed by linear regression.
Details on mating procedure:
- Impregnation procedure: cohoused
- If cohoused:
- M/F ratio per cage: 1:1
- Verification of same strain and source of both sexes: yes
- Proof of pregnancy: vaginal plug referred to as day 0 of pregnancy
- Any other deviations from standard protocol:
Duration of treatment / exposure:
day 6 through day 15 of gestation
Frequency of treatment:
daily
Duration of test:
gd 21 (scheduled sacrifice)
Dose / conc.:
30 mg/kg bw/day
Dose / conc.:
175 mg/kg bw/day
Dose / conc.:
450 mg/kg bw/day
No. of animals per sex per dose:
25 females/group; 50 control females
Control animals:
yes, concurrent vehicle
Details on study design:
no further data
Maternal examinations:
CAGE SIDE OBSERVATIONS: Yes
- Time schedule: daily
- Cage side observations : mortality

DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule: daily

BODY WEIGHT: Yes
- Time schedule for examinations: gd 0, 6, 11, 15, 21

FOOD CONSUMPTION : Yes
- Food consumption for each animal determined throughout gestation gd 0-21

WATER CONSUMPTION : No

POST-MORTEM EXAMINATIONS: Yes
- Sacrifice on gestation day 21
- Organs examined: body weight, liver, gravid uterine weight, number of corporal lutea, number and status of implementation sites
Ovaries and uterine content:
The ovaries and uterine content was examined after termination: Yes
Examinations included:
- Gravid uterus weight: Yes
- Number of corpora lutea: Yes
- Number of implantations: Yes
- Number of early resorptions: Yes
- Number of late resorptions: Yes
Fetal examinations:
- External examinations: Yes, all per litter
- Soft tissue examinations: Yes, half per litter
- Skeletal examinations: Yes, half per litter
- Head examinations: Yes, half per litter
Statistics:
Levene's test, ANOVA, t-test with bonferroni prohabilities, Kruskal-wallis test, Mann-Whitney U test, Fisher's exact test
Indices:
no data
Historical control data:
no data
Clinical signs:
effects observed, treatment-related
Mortality:
mortality observed, treatment-related
Body weight and weight changes:
effects observed, treatment-related
Food consumption and compound intake (if feeding study):
effects observed, treatment-related
Food efficiency:
not specified
Ophthalmological findings:
not examined
Haematological findings:
not examined
Clinical biochemistry findings:
not examined
Urinalysis findings:
not examined
Behaviour (functional findings):
not examined
Immunological findings:
not examined
Organ weight findings including organ / body weight ratios:
effects observed, treatment-related
Gross pathological findings:
not specified
Neuropathological findings:
not examined
Histopathological findings: non-neoplastic:
not specified
Histopathological findings: neoplastic:
not examined
Other effects:
not specified
Number of abortions:
no effects observed
Pre- and post-implantation loss:
no effects observed
Total litter losses by resorption:
no effects observed
Early or late resorptions:
no effects observed
Dead fetuses:
no effects observed
Changes in pregnancy duration:
no effects observed
Description (incidence and severity):
Migrated Data from removed field(s)
Field "Effects on pregnancy duration" (Path: ENDPOINT_STUDY_RECORD.DevelopmentalToxicityTeratogenicity.ResultsAndDiscussion.ResultsMaternalAnimals.MaternalDevelopmentalToxicity.EffectsOnPregnancyDuration): no effects observed
Changes in number of pregnant:
no effects observed
Other effects:
not specified
Details on maternal toxic effects:
Maternal toxicity:
mortality: 3/25 females at 450 mg/kg bw/day 
No abortions or early deliveries (1 litter at 30 mg/kg bw was fully resorbed)
450 mg/kg bw: decreased food consumption, stat. sign. reduction in periodic maternal body weight  and weight gain during dosing, 
maternal gestational weight gain reduced when corrected for the weight of the gravid uterus and reduced maternal terminal bw, relative but not absolute liver weight was increased
clin. signs  of toxicity: 
hypoactivity, ataxia and tremors, prone position, audible respiration and perioral wetness.
Gestational parameters were unaffected by treatment except fetal body weight per litter were reduced at 450 mg/kg bw.
Key result
Dose descriptor:
NOAEL
Effect level:
175 mg/kg bw/day
Based on:
test mat.
Basis for effect level:
other: 450 mg/kg bw/d: hypoactivity, ataxia, tremors, twitches, prone positioning, audible respiration and perioral wetness, statistically signifcant reduction in periodic maternal body weights and weight gain during the dosing period
Key result
Abnormalities:
no effects observed
Fetal body weight changes:
effects observed, treatment-related
Description (incidence and severity):
Migrated Data from removed field(s)
Field "Fetal/pup body weight changes" (Path: ENDPOINT_STUDY_RECORD.DevelopmentalToxicityTeratogenicity.ResultsAndDiscussion.ResultsFetuses.FetalPupBodyWeightChanges): effects observed, treatment-related
Reduction in number of live offspring:
no effects observed
Changes in sex ratio:
no effects observed
Changes in litter size and weights:
no effects observed
Changes in postnatal survival:
no effects observed
External malformations:
no effects observed
Skeletal malformations:
effects observed, treatment-related
Visceral malformations:
no effects observed
Other effects:
not specified
Details on embryotoxic / teratogenic effects:
fetal evaluations:
No significant changes in the incidence of any individual malformation, malformation by category (external, visceral including craniofacial or skeletal) or total malformations for any dose group.
450 mg/kg bw: 7 skeletal variations exhibited sign. different incidences relative to those in the control groups: only 3 of these findings indicate slight fetotoxicity: incidence of cervical centrum 6 bilobed, reduced number of ossified caudal segments, unossified sternebrae, reduced incidence of unossified cervical centrum no. 7, poorly ossified parietal skull bone (30 mg/kg bw), reduced incidence of some (1-4) proximal phalanges of the hind limb unossified and increased incidence of of poorly ossified thoracic centrum number 13 (175 mg/kg bw/d)
p-Cresol caused mild fetotoxicity at the 450 mg/kg, as seen by reduced ossification in three skeletal districts. In addition, fetal body weight was reduced at the 450 mg/kg dose level. There was no treatment-related increased incidence of malformations at any dosage.

Key result
Dose descriptor:
NOEL
Effect level:
175 mg/kg bw/day
Based on:
test mat.
Sex:
male/female
Basis for effect level:
other: 450 mg/kg bw/d: Slight fetotoxicity seen as three skeletal variations consistent with reduced fetal body weights.
Key result
Abnormalities:
effects observed, treatment-related
Localisation:
other: 450 mg/kg bw/d: skeletal variations (reduced ossification)
Key result
Developmental effects observed:
no
Conclusions:
Developmental toxicity study according to TSCA Health Effects Test guidelines for Specific Organ/Tissue Toxicity - Developmental Toxicity (EPA, 1984,1987):
Administration of p-cresol by gavage to time-pregnant Sprague-Dawley rats during organogenesis at 0.0, 30.0, 175.0, or 450.0 mg/kg bw/d resulted in maternal toxicity at 450 mg/kg bw/d and included mortality, clinical signs of toxicity, reduced weight gain and food consumption during dosing and reduced gestational weight gain corrected for the gravid uterus. Slight developmental toxicity was observed at 450 mg/kg bw/d and included reduced ossification in three skeletal districts in addition with reduced fetal body weight. Thus, the NOAEL for maternal toxicity and the NOEL for developmental toxicity is 175 mg/kg bw/d.
Endpoint:
developmental toxicity
Type of information:
experimental study
Adequacy of study:
weight of evidence
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study
Qualifier:
according to
Guideline:
other: TSCA Health Effects Test guidelines for Specific Organ/Tissue Toxicity - Developmental Toxicity (EPA, 1984,1987)
Deviations:
no
GLP compliance:
yes
Limit test:
no
Species:
rabbit
Strain:
New Zealand White
Details on test animals and environmental conditions:
TEST ANIMALS
- Source: Hazleton-Dutchland Laboratories, Inc. , Denver, PA, USA
- Age at study initiation: 5.5 months
- Weight at study initiation: 2.5 kg
- Housing: after malting: singly
- Diet : ad libitum
- Water: ad libitum
- Acclimation period: 2 weeks


ENVIRONMENTAL CONDITIONS
- Temperature (°F): 72
- Humidity (%): 40-60
- Photoperiod (hrs dark / hrs light): 12/12

Route of administration:
oral: gavage
Vehicle:
corn oil
Details on exposure:
PREPARATION OF DOSING SOLUTIONS:
Dosing formulations were prepared by weighing the amount of test chemical into a volumetric flask and diluting to volume with certified corn oil.
The resulting solutions were mixed by repeated inversions and stored at room temperature.

Analytical verification of doses or concentrations:
yes
Details on analytical verification of doses or concentrations:
A standard stock solution (1 mg/mL) was prepared as needed by weighing 50 mg m-cresol into a 50 mL volumetric flask and diluting to volume with propanol. Standards ranging from 10 to 100 ng/mL were prepared by diluting the stock solution with
propanol. 10 µL of each standard was injected onto the HPLC. The actual conentration of each dosing solution was calculated from the equitation for the standard curve developed by linear regression.
Details on mating procedure:
- Impregnation procedure: cohoused
- If cohoused:
- M/F ratio per cage: 1:1
- Verification of same strain and source of both sexes: yes
- Proof of pregnancy: vaginal plug referred to as day 0 of pregnancy
Duration of treatment / exposure:
day 6 through day 18 of gestation
Frequency of treatment:
once daily
Duration of test:
until gd 29
Dose / conc.:
5 mg/kg bw/day
Dose / conc.:
50 mg/kg bw/day
Dose / conc.:
100 mg/kg bw/day
No. of animals per sex per dose:
14 females/group; control females: 28
Control animals:
yes, concurrent vehicle
Details on study design:
no furhter details
Maternal examinations:
CAGE SIDE OBSERVATIONS: Yes
- Time schedule: twice daily

DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule: twice daily

BODY WEIGHT: Yes
- Time schedule for examinations: gd 0, 6, 12, 18, 24, 29

FOOD CONSUMPTION: Yes

WATER CONSUMPTION: No

POST-MORTEM EXAMINATIONS: Yes
- Sacrifice on gestation day 29
- Organs examined: stomach gland, liver, gall bladder, kidneys, uterus

Ovaries and uterine content:
The ovaries and uterine content was examined after termination: Yes
Examinations included:
- Gravid uterus weight: Yes
- Number of corpora lutea: Yes
- Number of implantations: Yes
- Number of early resorptions: Yes
- Number of late resorptions: Yes
Fetal examinations:
-determination of number of fetuses alive: yes
-determination of number of dead fetuses: yes
-determination of sex ratio: yes
- External examinations: Yes, all per litter
- Soft tissue examinations: Yes, all per litter
- Skeletal examinations: Yes, all per litter
- Head examinations: Yes, half per litter
Statistics:
Levene's test, ANOVA with Bonferroni prohability, t-test, Kruskal-Wallis test, Mann-Whitney U test, Fisher's exact test
Indices:
no data
Historical control data:
no data
Details on maternal toxic effects:
>= 50 mg/kg bw/day: audible respiration, ocular discharge

Key result
Dose descriptor:
NOAEL
Effect level:
5 mg/kg bw/day
Based on:
test mat.
Basis for effect level:
other: >=50 mg/kg bw clinical signs including audible respiration and ocular discharge
Key result
Abnormalities:
no effects observed
Fetal body weight changes:
no effects observed
Description (incidence and severity):
Migrated Data from removed field(s)
Field "Fetal/pup body weight changes" (Path: ENDPOINT_STUDY_RECORD.DevelopmentalToxicityTeratogenicity.ResultsAndDiscussion.ResultsFetuses.FetalPupBodyWeightChanges): no effects observed
Reduction in number of live offspring:
no effects observed
Changes in litter size and weights:
no effects observed
Changes in postnatal survival:
no effects observed
External malformations:
no effects observed
Skeletal malformations:
no effects observed
Visceral malformations:
no effects observed
Other effects:
no effects observed
Details on embryotoxic / teratogenic effects:
Embryotoxic / teratogenic effects:no effects
Key result
Dose descriptor:
NOAEL
Effect level:
100 mg/kg bw/day
Based on:
test mat.
Sex:
male/female
Basis for effect level:
other: No developmental effects observed until the highest dose tested.
Key result
Abnormalities:
no effects observed
Key result
Developmental effects observed:
no
Conclusions:
Developmental toxicity study according to TSCA Health Effects Test guidelines for Specific Organ/Tissue Toxicity - Developmental Toxicity (EPA, 1984,1987):
Administration of m-cresol by gavage to time-pregnant New Zealand White rabbits during organogenesis at 0.0, 5.0, 50.0, 100.0 mg/kg bw/d caused clinical signs of toxicity including audible respiration and ocular discharge from 50 mg/kg bw/d onwards (NOAEL (maternal toxicity) 5.0 mg/kg bw/d). No developmental effects were seen at any dosage employed (NOAEL (developmental toxicity) 100 mg/kg bw/d).
Endpoint:
developmental toxicity
Type of information:
experimental study
Adequacy of study:
weight of evidence
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study
Qualifier:
according to
Guideline:
other: TSCA Health Effects Test guidelines for Specific Organ/Tissue Toxicity - Developmental Toxicity (EPA, 1984,1987)
Deviations:
no
GLP compliance:
yes
Limit test:
no
Species:
rat
Strain:
Sprague-Dawley
Details on test animals and environmental conditions:
TEST ANIMALS
- Source: Charles River Breeding labarotory, Kingston, NY, USA
- Age at study initiation: 56 days at arrival
- Weight at study initiation: 228-231g
- Housing: after mating: singly
- Diet: ad libitum
- Water: ad libitum
- Acclimation period: 2 weeks


ENVIRONMENTAL CONDITIONS
- Temperature (°F): 72
- Humidity (%): 40 - 60
- Photoperiod (hrs dark / hrs light): 12/12
Route of administration:
oral: gavage
Vehicle:
corn oil
Details on exposure:
PREPARATION OF DOSING SOLUTIONS:
Dosing formulations were prepared by weighing the amount of test chemical into a volumetric flask and diluting to volume with certified corn oil.
The resulting solutions were mixed by repeated inversions and stored at room temperature.

Analytical verification of doses or concentrations:
yes
Details on analytical verification of doses or concentrations:
A standard stock solution (1 mg/mL) was prepared as needed by weighing 50 mg m-cresol into a 50 mL volumetric flask and diluting to volume with propanol. Standards ranging from 10 to 100 ng/mL were prepared by diluting the stock solution with
propanol. 10 µL of each standard was injected onto the HPLC. The actual conentration of each dosing solution was calculated from the equitation for the standard curve developed by linear regression.
Details on mating procedure:
- Impregnation procedure: cohoused
- If cohoused:
- M/F ratio per cage: 1:1
- Verification of same strain and source of both sexes: yes
- Proof of pregnancy: vaginal plug referred to as day 0 of pregnancy
Duration of treatment / exposure:
day 6 through day 15 of gestation
Frequency of treatment:
daily
Duration of test:
gd 21 (scheduled sacrifice)
Dose / conc.:
30 mg/kg bw/day
Dose / conc.:
175 mg/kg bw/day
Dose / conc.:
450 mg/kg bw/day
No. of animals per sex per dose:
25 females/ group, 50 control females
Control animals:
yes, concurrent vehicle
Details on study design:
no further data
Maternal examinations:
CAGE SIDE OBSERVATIONS: Yes
- Time schedule: daily
- Cage side observations: mortality

DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule: twice daily

BODY WEIGHT: Yes
- Time schedule for examinations: gd 0, 6, 11, 15, 21

FOOD CONSUMPTION: Yes
- Food consumption for each animal determined throughout gestation gd 0-21

WATER CONSUMPTION: No

POST-MORTEM EXAMINATIONS: Yes
- Sacrifice on gestation day 21
- Organs examined: body weight, liver, gravid uterine weight, number of corpora lutea, number and status of implantation sites


Ovaries and uterine content:
The ovaries and uterine content was examined after termination: Yes
Examinations included:
- Gravid uterus weight: Yes
- Number of corpora lutea: Yes
- Number of implantations: Yes
- Number of early resorptions: Yes
- Number of late resorptions: Yes
Fetal examinations:
- External examinations: Yes, all per litter
- Soft tissue examinations: Yes, half per litter
- Skeletal examinations: Yes, half per litter
- Head examinations: Yes, half per litter
Statistics:
Levene's test, ANOVA, t-test with Bonferroni prohabilities, Kruskal-Wallis test, Mann-Whitney U test, Fishers exact test
Indices:
no data
Historical control data:
no data
Clinical signs:
effects observed, treatment-related
Mortality:
no mortality observed
Body weight and weight changes:
effects observed, treatment-related
Food consumption and compound intake (if feeding study):
effects observed, treatment-related
Food efficiency:
not specified
Ophthalmological findings:
not examined
Haematological findings:
not examined
Clinical biochemistry findings:
not examined
Urinalysis findings:
not examined
Behaviour (functional findings):
not examined
Immunological findings:
not examined
Organ weight findings including organ / body weight ratios:
effects observed, treatment-related
Gross pathological findings:
not specified
Neuropathological findings:
not examined
Histopathological findings: non-neoplastic:
not specified
Histopathological findings: neoplastic:
not examined
Other effects:
not specified
Number of abortions:
no effects observed
Pre- and post-implantation loss:
no effects observed
Total litter losses by resorption:
no effects observed
Early or late resorptions:
no effects observed
Dead fetuses:
no effects observed
Changes in pregnancy duration:
no effects observed
Description (incidence and severity):
Migrated Data from removed field(s)
Field "Effects on pregnancy duration" (Path: ENDPOINT_STUDY_RECORD.DevelopmentalToxicityTeratogenicity.ResultsAndDiscussion.ResultsMaternalAnimals.MaternalDevelopmentalToxicity.EffectsOnPregnancyDuration): no effects observed
Changes in number of pregnant:
no effects observed
Other effects:
not specified
Details on maternal toxic effects:
no mortality,
no treatment-related abortions or early delivery,
no treatment related lesions in dams at scheduled sacrifice

450 mg/kg bw/day (significant changes only)
significant reduction in mean maternal body weights:
gd 11: 261 g versus 276 g in controls
gd 15: 281 g versus 300 g in controls
reduction in mean weight gain during dosing
reduced mean gestational weight gain
gd 0-21: 145 g versus 163 g in controls
clinical signs of toxicity:
predominantly hypoactivity, ataxia, tremors, twitches, prone positioning, audible rtespiration, perioral wetness
reduction in mean food consumption
pretratment period: day 6-9: 15 g versus 21 g of controls
treatment period gd 6-15: 19 g versus 22 g of controls
relative (not absolute) liver weight was increased
4.9 % versus 4.52 % in controls
Key result
Dose descriptor:
NOAEL
Effect level:
175 mg/kg bw/day
Basis for effect level:
other: 450 mg/kg bw/day: significant reduction in periodic maternal body weights and weight gain during the dosing period in addition with clinical signs of toxicity
Key result
Abnormalities:
no effects observed
Fetal body weight changes:
no effects observed
Description (incidence and severity):
Migrated Data from removed field(s)
Field "Fetal/pup body weight changes" (Path: ENDPOINT_STUDY_RECORD.DevelopmentalToxicityTeratogenicity.ResultsAndDiscussion.ResultsFetuses.FetalPupBodyWeightChanges): no effects observed
Reduction in number of live offspring:
no effects observed
Changes in sex ratio:
no effects observed
Changes in litter size and weights:
no effects observed
Changes in postnatal survival:
no effects observed
External malformations:
no effects observed
Skeletal malformations:
no effects observed
Visceral malformations:
no effects observed
Other effects:
not specified
Details on embryotoxic / teratogenic effects:
Embryotoxic / teratogenic effects:no effects

Key result
Dose descriptor:
NOAEL
Effect level:
450 mg/kg bw/day
Based on:
test mat.
Sex:
male/female
Basis for effect level:
other: No developmental effects observed until the highest dose tested.
Key result
Abnormalities:
no effects observed
Key result
Developmental effects observed:
no
Conclusions:
Developmental toxicity study according to TSCA Health Effects Test guidelines for Specific Organ/Tissue Toxicity - Developmental Toxicity (EPA, 1984,1987):
Administration of m-cresol by gavage to time-pregnant-Sprague Dawley rats during organogenesis at 0.0, 30, 175, 450 mg/kg bw/d resulted in maternal toxicity at 450 mg/kg bw/day including significant reduction in periodic maternal body weights and weight gain during the dosing period in addition with clinical signs of toxicity (NOAEL (maternal toxicity) 175 mg/kg bw/d). m-Cresol did not induce fetotoxicity or malformations at any dose level tested (NOAEL (developmental toxicity) >450 mg/kg bw).
Endpoint:
developmental toxicity
Type of information:
experimental study
Adequacy of study:
weight of evidence
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study
Qualifier:
according to
Guideline:
other: TSCA Health Effects Test Guidelines for Specific Organ/Tessue Toxicity-Developmental Toxicity (EPA, 1984, 1987)
Deviations:
no
GLP compliance:
yes
Limit test:
no
Species:
rabbit
Strain:
New Zealand White
Details on test animals and environmental conditions:
TEST ANIMALS
- Source: Hazleton-Dutchland Laboratories Inc., Denver, PA, USA
- Age at study initiation: 5.5 months
- Weight at study initiation: 2.5 kg
- Housing: after mating: singly
- Diet: ad libitum
- Water: ad libitum
- Acclimation period: 2 weeks


ENVIRONMENTAL CONDITIONS
- Temperature (°F): 72
- Humidity (%): 40-60
- Photoperiod (hrs dark / hrs light): 12/12
Route of administration:
oral: gavage
Vehicle:
corn oil
Details on exposure:
PREPARATION OF DOSING SOLUTIONS:
Dosing formulations were prepared by weighing the amount of test chemical into a volumetric flask and diluting to volume with certified corn oil. The resulting solutions were mixed by repeated inversions and stored at room temperature.

Analytical verification of doses or concentrations:
yes
Details on analytical verification of doses or concentrations:
A standard stock solution (1 mg/mL) was prepared as needed by weighing 50 mg o-cresol into a 50 mL volumetric flask and ddiluting to volume with propanol. Standards ranging from 10 to 100 ng/mL were prepared by diluting the stock solution with propanol. 10 mL of each standard was injected onto the HPLC. The actual concentration of each dosing solution was calculated from the equitation for the standard curve developed by linear regression.
Details on mating procedure:
- Impregnation procedure: cohoused
- If cohoused:
- M/F ratio per cage: 1:1
- Verification of same strain and source of both sexes: yes
- Proof of pregnancy: vaginal plug referred to as day 0 of pregnancy
Duration of treatment / exposure:
13 d (gd 6-18)
Frequency of treatment:
once daily
Duration of test:
until gd 29
Dose / conc.:
5 mg/kg bw/day
Dose / conc.:
50 mg/kg bw/day
Dose / conc.:
100 mg/kg bw/day
No. of animals per sex per dose:
14 females /group, control females: 28
Control animals:
yes, concurrent vehicle
Details on study design:
no further details
Maternal examinations:
CAGE SIDE OBSERVATIONS: Yes
- Time schedule: twice daily

DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule: twice daily

BODY WEIGHT: Yes
- Time schedule for examinations: gd 0,6, 12, 18, 24, 29

FOOD CONSUMPTION Yes

WATER CONSUMPTION: No

POST-MORTEM EXAMINATIONS: Yes
- Sacrifice on gestation day 29
- Organs examined: stomach gland, liver, gall bladder, kidneys, uterus
Ovaries and uterine content:
The ovaries and uterine content was examined after termination: Yes
Examinations included:
- Gravid uterus weight: Yes
- Number of corpora lutea: Yes
- Number of implantations: Yes
- Number of early resorptions: Yes
- Number of late resorptions: Yes
Fetal examinations:
-determination of the number of fetuses alive: yes
-determination of the number of dead fetuses: yes
-determination of sex ratio: yes
- External examinations: Yes, all per litter
- Soft tissue examinations: Yes, all per litter
- Skeletal examinations: Yes, all per litter
- Head examinations: Yes, half per litter
Statistics:
Levene's test, ANOVA with Bonferroni prohability, pooled t-test, Kruskal -Wallis test, Mann-Whitney U test, Fisher's exact test
Indices:
no data
Historical control data:
no data
Clinical signs:
effects observed, treatment-related
Dermal irritation (if dermal study):
not examined
Mortality:
no mortality observed
Body weight and weight changes:
no effects observed
Food consumption and compound intake (if feeding study):
no effects observed
Food efficiency:
not specified
Water consumption and compound intake (if drinking water study):
not specified
Ophthalmological findings:
not examined
Haematological findings:
not examined
Clinical biochemistry findings:
not examined
Urinalysis findings:
not examined
Behaviour (functional findings):
not examined
Immunological findings:
not examined
Organ weight findings including organ / body weight ratios:
not specified
Gross pathological findings:
not specified
Neuropathological findings:
not examined
Histopathological findings: non-neoplastic:
not specified
Histopathological findings: neoplastic:
not examined
Other effects:
not specified
Number of abortions:
no effects observed
Pre- and post-implantation loss:
no effects observed
Total litter losses by resorption:
no effects observed
Early or late resorptions:
no effects observed
Dead fetuses:
no effects observed
Changes in pregnancy duration:
no effects observed
Description (incidence and severity):
Migrated Data from removed field(s)
Field "Effects on pregnancy duration" (Path: ENDPOINT_STUDY_RECORD.DevelopmentalToxicityTeratogenicity.ResultsAndDiscussion.ResultsMaternalAnimals.MaternalDevelopmentalToxicity.EffectsOnPregnancyDuration): no effects observed
Changes in number of pregnant:
no effects observed
Other effects:
not specified
Details on maternal toxic effects:
all groups:
no treatment related deaths, no significant changes in periodic maternal body weights or weight gain, no treatment related effects on food consumption, no abortions, no early deliveries, gestational parameters were not affected
clinical observations:
50.0 and 100.0 mg-group: audible respiration, ocular discharge
 

NOEL (general toxicity): 5.0 mg/kg bw/day
NOAEL (developmental): 50 mg/kg bw/day
NOAEL (maternal toxicity): 100 mg/kg bw/d
Key result
Dose descriptor:
NOAEL
Effect level:
5 mg/kg bw/day
Based on:
test mat.
Basis for effect level:
other: >= 50 mg/kg bw/d: clinical signs of toxicity including hypoactivity, audible respiration, ocular discharge
Key result
Abnormalities:
no effects observed
Fetal body weight changes:
not specified
Description (incidence and severity):
Migrated Data from removed field(s)
Field "Fetal/pup body weight changes" (Path: ENDPOINT_STUDY_RECORD.DevelopmentalToxicityTeratogenicity.ResultsAndDiscussion.ResultsFetuses.FetalPupBodyWeightChanges): not specified
Reduction in number of live offspring:
not specified
Changes in sex ratio:
not specified
Changes in litter size and weights:
not specified
Changes in postnatal survival:
not specified
External malformations:
effects observed, treatment-related
Skeletal malformations:
effects observed, treatment-related
Visceral malformations:
no effects observed
Other effects:
not specified
Details on embryotoxic / teratogenic effects:
100.0 mg-group: slight fetotoxicity: ecchymosis on the head: 4/129 fetuses in 4/14 litters versus none in controls, poorly ossified sternum: 52/129 fetuses in 14/14 litters versus 62/212 fetuses in 16/23 litters
NOAEL (developmental): 50 mg/kg bw/day
Key result
Dose descriptor:
NOEL
Effect level:
50 mg/kg bw/day
Based on:
test mat.
Sex:
male/female
Basis for effect level:
other: 100 mg/kg bw/day: slight fetotoxicity (increased incidence of 1 external variation and 1 skeletal variation) in the absence of any other indications of toxicity for the conceptus
Key result
Abnormalities:
effects observed, treatment-related
Localisation:
other: ecchymosis on the head / poorly ossified sternum
Description (incidence and severity):
1 external variation and 1 skeletal variation at 100 mg/kg bw/day
Key result
Developmental effects observed:
no
Conclusions:
Developmetal toxicity study according to TSCA Health Effects Test Guidelines for Specific Organ/Tessue Toxicity-Developmental Toxicity (EPA, 1984, 1987):
Administration of o-cresol by gavage to time-pregnant New Zealand White rabbits during organogenesis at 0.0, 5.0, 50.0 or 100 mg/kg bw/d caused in dams hypoactivity, audible respiration, ocular discharge from 50 mg/kg bw/d onwards (NOAEL general toxicity: 5 mg/kg bw/day) and slight fetotoxicity observed as increased incidence of one external variation and one skeletal variation in the absence of any other indications of toxicity for the conceptus at 100 mg/kg bw/day: NOEL (developmental toxicity): 50 mg/kg bw/d. Based on the fact that no abortions, no early deliveries were observed and gestational parameters were not affected: NOAEL (maternal toxicity): 100.0 mg/kg bw/d.                     
Endpoint:
developmental toxicity
Type of information:
experimental study
Adequacy of study:
weight of evidence
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study
Qualifier:
according to
Guideline:
other: TSCA Health Effect Guidelines for Specific Organ/Tissue Toxicity - Developmental Toxicity (EPA 1984, 1987)
Deviations:
no
GLP compliance:
yes
Limit test:
no
Species:
rat
Strain:
Sprague-Dawley
Details on test animals and environmental conditions:
TEST ANIMALS
- Source: Charles River Breeding Laboratory, Kingston, NY, USA
- Weight at study initiation: 228-230 g
- Housing: after mating singly
- Diet: ad libitum
- Water: ad libitum
- Acclimation period: 2 week

ENVIRONMENTAL CONDITIONS
- Temperature (°F): 72
- Humidity (%): 40-60
- Photoperiod (hrs dark / hrs light): 12/12

Route of administration:
oral: gavage
Vehicle:
corn oil
Details on exposure:
PREPARATION OF DOSING SOLUTIONS:
Dosing formulations were prepared by weighing the amount of test chemical into a volumetric flask and diluting to volume with certified corn oil. The resulting solutions were mixed by repeated inversions and stored at room temperature.
Analytical verification of doses or concentrations:
yes
Details on analytical verification of doses or concentrations:
A standard stock solution (1 mg/mL) was prepared as needed by weighing 50 mg o-cresol into a 50 mL volumetric flask and diluting to volume with propanol. Standards ranging from 10 to 100 ng/mL were prepared by diluting the stock solution with propanol. 10 µL of each standard was injected onto the HPLC. The actual concentration of each dosing solution was calculated from the equitation for the standard curve developed by linear regression.
Details on mating procedure:
- Impregnation procedure: cohoused
- If cohoused:
- M/F ratio per cage: 1:1
- Verification of same strain and source of both sexes: yes
- Proof of pregnancy: vaginal plug referred to as day 0 of pregnancy
Duration of treatment / exposure:
10 d (gd 6-15)
Frequency of treatment:
once daily
Duration of test:
gd 21 (scheduled sacrifice)
Dose / conc.:
30 mg/kg bw/day
Dose / conc.:
175 mg/kg bw/day
Dose / conc.:
450 mg/kg bw/day
No. of animals per sex per dose:
25 females /group, 50 control females
Control animals:
yes, concurrent vehicle
Details on study design:
no further data
Maternal examinations:
CAGE SIDE OBSERVATIONS: Yes
- Time schedule: daily
- Cage side observations: mortality

DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule: twice daily

BODY WEIGHT: Yes
- Time schedule for examinations: gd 0, 6, 11, 15, 21

FOOD CONSUMPTION Yes
- Food consumption for each animal determined throughout gestation gd 0-21

WATER CONSUMPTION No

POST-MORTEM EXAMINATIONS: Yes
- Sacrifice on gestation day 21
- Organs examined: body weight, liver, gravid uterine weight, number of corpora lutea, number and status of implantation sites



Ovaries and uterine content:
The ovaries and uterine content was examined after termination: Yes
Examinations included:
- Gravid uterus weight: Yes
- Number of corpora lutea: Yes
- Number of implantations: Yes
- Number of early resorptions: Yes
- Number of late resorptions: Yes
Fetal examinations:
- External examinations: Yes, all per litter
- Soft tissue examinations: Yes, all per litter
- Skeletal examinations: Yes, all per litter
- Head examinations: Yes, half per litter
Statistics:
Levene's test for equal variances, ANOVA, pooled t-test with Bonferroni probabilities for pairwise comparison, Kruskal-Wallis test, Mann-Whitney U-test, Fisher's exact test
Indices:
no data
Historical control data:
no data
Clinical signs:
effects observed, treatment-related
Dermal irritation (if dermal study):
not examined
Mortality:
mortality observed, treatment-related
Body weight and weight changes:
effects observed, treatment-related
Food consumption and compound intake (if feeding study):
effects observed, treatment-related
Food efficiency:
not specified
Water consumption and compound intake (if drinking water study):
not specified
Ophthalmological findings:
not examined
Haematological findings:
not examined
Clinical biochemistry findings:
not examined
Urinalysis findings:
not examined
Behaviour (functional findings):
not examined
Immunological findings:
not examined
Organ weight findings including organ / body weight ratios:
not specified
Gross pathological findings:
not specified
Neuropathological findings:
not examined
Histopathological findings: non-neoplastic:
not specified
Histopathological findings: neoplastic:
not examined
Other effects:
not specified
Number of abortions:
no effects observed
Pre- and post-implantation loss:
no effects observed
Total litter losses by resorption:
no effects observed
Early or late resorptions:
no effects observed
Dead fetuses:
no effects observed
Changes in pregnancy duration:
no effects observed
Description (incidence and severity):
Migrated Data from removed field(s)
Field "Effects on pregnancy duration" (Path: ENDPOINT_STUDY_RECORD.DevelopmentalToxicityTeratogenicity.ResultsAndDiscussion.ResultsMaternalAnimals.MaternalDevelopmentalToxicity.EffectsOnPregnancyDuration): no effects observed
Changes in number of pregnant:
no effects observed
Other effects:
not specified
Details on maternal toxic effects:
Maternal toxicity: 450 mg-group: 4/25 died, significant reduction in periodic maternal body weight and weight gain during dosing, reduction of food consumption, clinical signs: at 450 mg/kg bw hypoactivity, ataxia, tremor, twitches, prone positioning, audible respiration, perioral wetness, for all groups: gestational parameters unaffected, no early delivery, no abortion;
 
NOAEL (maternal): 175.0 mg/kg bw/day
Key result
Dose descriptor:
NOAEL
Effect level:
175 mg/kg bw/day
Based on:
test mat.
Basis for effect level:
other: 450 mg/kg bw/day: treatment related clinical signs including hypoactivity, ataxia, tremor, twitches, prone positioning, audible respiration, perioral wetness, mortality of 4 dams, statistically significant reduction in body weights and body weight gain
Key result
Abnormalities:
no effects observed
Fetal body weight changes:
not specified
Description (incidence and severity):
Migrated Data from removed field(s)
Field "Fetal/pup body weight changes" (Path: ENDPOINT_STUDY_RECORD.DevelopmentalToxicityTeratogenicity.ResultsAndDiscussion.ResultsFetuses.FetalPupBodyWeightChanges): not specified
Reduction in number of live offspring:
not specified
Changes in sex ratio:
not specified
Changes in litter size and weights:
not specified
Changes in postnatal survival:
not specified
External malformations:
not specified
Skeletal malformations:
not specified
Visceral malformations:
effects observed, treatment-related
Other effects:
not specified
Details on embryotoxic / teratogenic effects:
Evaluation of offspring:
450 mg/kg bw: slight fetotoxicity:
one visceral variation: dilated lateral ventricles of the brain with no tissue compression;
NOAEL (developmental): 175.0 mg/kg bw/day
Key result
Dose descriptor:
NOEL
Effect level:
175 mg/kg bw/day
Based on:
test mat.
Sex:
male/female
Basis for effect level:
other: 450 mg/kg bw: slight fetotoxicity: one visceral variation: dilated lateral ventricles of the brain with no tissue compression;
Key result
Abnormalities:
effects observed, treatment-related
Localisation:
other: dilated lateral ventricles of the brain with no tissue compression
Description (incidence and severity):
one variation at 450 mg/kg bw
Key result
Developmental effects observed:
no
Conclusions:
Developmental toxicity study according to TSCA Health Effect Guidelines for Specific Organ/Tissue Toxicity - Developmental Toxicity (EPA 1984, 1987):
Administration of o-cresol by gavage to time-pregnant Sprague-Dawley rats during organogenesis at 0.0, 30.0, 175.0, 450.0 mg/kg bw/d resulted in significant maternal toxicity at 450 mg/kg bw/d including treatment related clinical signs (hypoactivity, ataxia, tremor, twitches, prone positioning, audible respiration, perioral wetness), mortality of 4 dams, statistically significant reduction in body weights and body weight gain (NOAEL (maternal toxicity) 175 mg/kg bw/d). Slight fetotoxicity only at 450 mg/kg bw/d as one visceral variation (dilatated lateral ventricles of the brain with no tissue compression). Thus, the NOEL (developmental toxicity) is 175 mg/kg bw/d.
Endpoint:
developmental toxicity
Type of information:
read-across from supporting substance (structural analogue or surrogate)
Remarks:
Summary of available data used for the endpoint assessment of the target substance
Adequacy of study:
key study
Justification for type of information:
refer to analogue justification provided in IUCLID section 13
Reason / purpose:
read-across source
Reason / purpose:
read-across source
Reason / purpose:
read-across source
Reason / purpose:
read-across source
Reason / purpose:
read-across source
Reason / purpose:
read-across source
Key result
Dose descriptor:
NOAEL
Remarks:
rat
Effect level:
175 mg/kg bw/day
Based on:
test mat.
Basis for effect level:
other: 450 mg/kg bw/day: significant reduction in periodic maternal body weights and weight gains in addition with clinical signs of toxicity / mortality
Remarks on result:
other: Source, CAS 95-48-7, o-cresol / CAS106-44-5, p-cresol / CAS 108-34-9, m-cresol; CMA, 1988
Key result
Dose descriptor:
NOAEL
Remarks:
rabbit
Effect level:
5 mg/kg bw/day
Based on:
test mat.
Basis for effect level:
other: >= 50 mg/kg bw/d: clinical signs of toxicity /mortality
Remarks on result:
other: Source, CAS 95-48-7, o-cresol / CAS106-44-5, p-cresol / CAS 108-34-9, m-cresol; CMA, 1988
Key result
Abnormalities:
no effects observed
Details on embryotoxic / teratogenic effects:
In the result table below the most critical and relevant value of the weight of evidence approach is given. In the following, the results are shown for the other source substances of this weight of evidence approach:
Source CAS 108-34-9: m-cresol: NOAEL (fetuses, rat) 450 mg/kg bw/day / NOAEL (fetuses, rabbit) 100 mg/kg bw/day (no developmental effects observed until the highest dose tested); CMA, 1988
Source CAS 106-44-5: p-cresol: NOAEL (fetuses, rabbit) 100 mg/kg bw/day (no developmental effects observed until the highest dose tested); CMA, 1988
Key result
Dose descriptor:
NOEL
Remarks:
rat
Effect level:
175 mg/kg bw/day
Based on:
test mat.
Sex:
male/female
Basis for effect level:
other: 450 mg/kg bw: slight fetotoxicity (o-cr.: visceral variation (dilated lateral ventricles of the brain with no tissue compression); p-cr.: three skeletal variations consistent with reduced fetal body weight)
Remarks on result:
other: Source, CAS 95-48-7, o-cresol / CAS106-44-5, p-cresol; CMA, 1988
Key result
Dose descriptor:
NOEL
Remarks:
rabbit
Effect level:
50 mg/kg bw/day
Based on:
test mat.
Sex:
male/female
Basis for effect level:
other: 100 mg/kg bw/day: slight fetotoxicity (increased incidence of 1 external variation and 1 skeletal variation) in the absence of any other indications of toxicity for the conceptus
Remarks on result:
other: Source, CAS 95-48-7, o-cresol, CMA, 1988
Key result
Abnormalities:
effects observed, treatment-related
Localisation:
other: o-cr.: dilated lateral ventricles of the brain with no tissue compression; p-cresol: skeletal variations (reduced ossification)
Description (incidence and severity):
at 450 mg/kg bw (rat); Source, CAS 95-48-7, o-cresol / CAS106-44-5, p-cresol; CMA, 1988
Key result
Abnormalities:
effects observed, treatment-related
Localisation:
other: ecchymosis on the head / poorly ossified sternum
Description (incidence and severity):
1 external variation and 1 skeletal variation at 100 mg/kg bw/day (rabbit); Source, CAS 95-48-7, o-cresol, CMA, 1988
Key result
Developmental effects observed:
no
Conclusions:
Developmental toxicity studies in rats and rabbits are available with the three isomers o-, p- and m-cresol. Treatment with the source substances resulted in NOAELs for maternal toxicity of 175 mg/kg bw/day in rats and 5 mg/kg bw/day in rabbits. For o- and p-cresol slight developmental toxicity in rats was observed in the hightest dose resulting in a NOEL of 175 mg/kg bw/day for developmental toxicity. In rabbits developmental effects in the highest dose for o-cresol was observed, leading to a NOEL for developmental toxicity of 50 mg/kg bw/day. All effects observed were variations which are considered to be of low concern as a variation can also be defined as a change that occurs within normal population under investigation and is unlikely to affect adversely survival or health. No abnormality, anomaly or malformation was observed. Thus, all effects observed are considered to be not adverse. m-cresol did not show any developmental effects up to the highest dose tested in rats and rabbits. Based on all available information (weight-of-evidence), following an analogue read-across approach, the NOAEL for developmental toxicity of Tar acids, Xylenol fraction (CAS 84989-06-0) is considered to be 100 mg/kg bw/day; this value is taken forward for hazard and subsequent risk assessment.
Executive summary:

Several developmental toxicity studies are available for the source substances o-, p-, and m-cresol in rats and rabbits. No adverse effects were observed in rats and rabbits regarding developmental toxicity up to the highest dose tested (for rats 450 mg/kg bw/day, for rabbits 100 mg/kg bw/day). Whilst no studies on toxicity to development have been conducted with tar acid, xylenol fraction, the experimental data available on cresols are considered to be suitable and meaningful to predict toxicity to reproduction (fertility) of the target substance.

Effect on developmental toxicity: via oral route
Endpoint conclusion:
adverse effect observed
Dose descriptor:
NOAEL
100 mg/kg bw/day
Study duration:
subacute
Species:
rabbit
Quality of whole database:
Taken together, the information from these independent sources is consistent and provides sufficient weight of evidence for hazard assessment leading to an endpoint conclusion in accordance with Annex XI, 1.2, of Regulation (EC) No 1907/2006. Therefore, the available information as a whole is sufficient to fulfil the standard information requirements set out in Annex IX, 8.7, in accordance with Annex XI, 1.5, of Regulation (EC) No 1907/2006.
Effect on developmental toxicity: via inhalation route
Endpoint conclusion:
no study available
Effect on developmental toxicity: via dermal route
Endpoint conclusion:
no study available
Additional information

Justification for read-across

There are no experimental data for effects on developmental toxicity available for Tar acids, Xylenol fraction (CAS 84989-06-0). In order to fulfil the standard data requirements defined in Regulation (EC) No 1907/2006, Annex IX, 8.7, read-across from appropriate substances is conducted in accordance with Regulation (EC) No 1907/2006, Annex XI, 1.5.

According to Article 13 (1) of Regulation (EC) No 1907/2006, "information on intrinsic properties of substances may be generated by means other than tests, provided that the conditions set out in Annex XI are met”. In particular for human toxicity, information shall be generated whenever possible by means other than vertebrate animal tests, which includes the use of information from structurally related substances (grouping or read-across) “to avoid the need to test every substance for every endpoint”.

Tar acids, Xylenol fraction (CAS 84989-06-0) is an UVCB substance comprised of the main constituents xylenols (all isomers in total > 60%; 2,4- and 2,5-xylenol > 40%), ethyl phenols (< 30%) and cresols (< 25%). The read-across approach is therefore based on the main constituents of Tar acids, Xylenol fraction (CAS 84989-06-0), given common functional groups, common precursors and the likelihood of common breakdown products via biological processes. For further details on the read-across approach, please refer to the analogue justification in section 13 of the technical dossier.

For the evaluation of the effects on developmental toxicity read-across from reliable data on the analogue substances mixed xylenols, mixed ethyl phenols as well as to the cresol isomers (m- (CAS 108-39-4), p- (CAS 106-44 5) and o-cresol (CAS 95-48-7)) was conducted in order to fulfill the requirements defined in Regulation (EC) No 1907/2006, Annex IX, 8.7.

o-cresol

A developmental toxicity study in rats according to TSCA Health Effect Guidelines for Specific Organ/Tissue Toxicity - Developmental Toxicity (EPA 1984, 1987) is available for o-cresol (CMA, 1988g). Administration of o-cresol by gavage to time-pregnant Sprague-Dawley rats during organogenesis (gestation day 6 – 15) at 0, 30, 175, and 450 mg/kg bw/day resulted in significant maternal toxicity at 450 mg/kg bw/day including treatment related clinical signs (hypoactivity, ataxia, tremor, twitches, prone positioning, audible respiration, perioral wetness), mortality of 4 dams, statistically significant reduction in body weights and body weight gain. Thus, a NOAEL for maternal toxicity of 175 mg/kg bw/day was derived. Slight fetotoxicity only at 450 mg/kg bw/day as one visceral variation (dilatated lateral ventricles of the brain with no tissue compression) was observed. A variation can be defined as a change that occurs within the normal population under investigation and is unlikely to affect adversely survival or health. Therefore, the observed visceral variation is considered to be non-adverse. Furthermore, this variation was observed while maternal toxicity was present. Thus, the NOAEL (developmental toxicity) is 450 mg/kg bw/day.

In a two generation study with o-cresol the NOAEL for developmental toxicity was set to 175 mg/kg bw/day based on significantly reduced body weights in F1 males and in significantly reduced lactation index in F2 at 450 mg/kg bw/day.

A developmental toxicity study in rabbits according to TSCA Health Effect Guidelines for Specific Organ/Tissue Toxicity - Developmental Toxicity (EPA 1984, 1987) is available for o-cresol (CMA, 1988h). Administration of o-cresol by gavage to time-pregnant New Zealand White rabbits during organogenesis (gestation day 6 - 18) at 0, 5, 50 or 100 mg/kg bw/day caused in dams hypoactivity, audible respiration, ocular discharge from 50 mg/kg bw/day onwards. Thus, leading to a NOAEL for maternal toxicity of 5 mg/kg bw/day. No abortions, no early deliveries were observed and gestational parameters were not affected. Slight fetotoxicity observed as increased incidence of one external variation and one skeletal variation in the absence of any other indications of toxicity for the conceptus at 100 mg/kg bw/day. A variation can be defined as a change that occurs within the normal population under investigation and is unlikely to affect adversely survival or health. Therefore, the observed external and skeletal variations are considered to be non-adverse. Furthermore, those variations were observed while maternal toxicity was present. Thus, the NOAEL (developmental toxicity) is 100 mg/kg bw/day.

p-cresol

A developmental toxicity study in rats according to TSCA Health Effect Guidelines for Specific Organ/Tissue Toxicity - Developmental Toxicity (EPA 1984, 1987) is available for p-cresol (CMA, 1988g). Administration of p-cresol by gavage to time-pregnant Sprague-Dawley rats during organogenesis (gestation day 6 – 15) at 0, 30, 175, and 450 mg/kg bw/day resulted in maternal toxicity at 450 mg/kg bw/day and included mortality, clinical signs of toxicity, reduced weight gain and food consumption during dosing and reduced gestational weight gain corrected for the gravid uterus. Thus, leading to a NOAEL for maternal toxicity of 175 mg/kg bw/day. Slight developmental toxicity was observed at 450 mg/kg bw/day and included variations as e.g. reduced ossification in three skeletal districts in addition with reduced fetal body weight. A variation can be defined as a change that occurs within the normal population under investigation and is unlikely to affect adversely survival or health. Reduced fetal body weight is considered to be a retardation (delay in growth) which is also considered of low concern especially while maternal toxicity is present. Therefore, the observed variations and retardation is considered to be non-adverse. Furthermore, those findings were observed while maternal toxicity was present. Thus, the NOAEL (developmental toxicity) is 450 mg/kg bw/day.

In a two generation study with p-cresol the NOAEL for developmental toxicity was set to 175 mg/kg bw/day based on toxic effects in the F2 litters of the high dose group animals and no clear evidence of toxic effects in F1 pups.

A developmental toxicity study in rabbits according to TSCA Health Effect Guidelines for Specific Organ/Tissue Toxicity - Developmental Toxicity (EPA 1984, 1987) is available for p-cresol (CMA, 1988h). Administration of p-cresol by gavage to time-pregnant New Zealand White rabbits during organogenesis (gestation day 6 - 18) at 0, 5, 50 or 100 mg/kg bw/day resulted in maternal toxicity at 50 and 100 mg/kg bw/day including mortality and clinical signs of toxicity. Thus, leading to a NOAEL for maternal toxicity of 5 mg/kg bw/day. No indications of developmental toxicity were observed. Thus, the NOAEL for developmental toxicity is 100 mg/kg bw/day.

m-cresol

A developmental toxicity study in rats according to TSCA Health Effect Guidelines for Specific Organ/Tissue Toxicity - Developmental Toxicity (EPA 1984, 1987) is available for m-cresol (CMA, 1988g). Administration of m-cresol by gavage to time-pregnant Sprague-Dawley rats during organogenesis (gestation day 6 – 15) at 0, 30, 175, and 450 mg/kg bw/day resulted in maternal toxicity at 450 mg/kg bw/day including significant reduction in periodic maternal body weights and weight gain during the dosing period in addition with clinical signs of toxicity. Therefore, a NOAEL for maternal toxicity of 175 mg/kg bw/day was derived. m-Cresol did not induce fetotoxicity or malformations at any dose level tested leading to a NOAEL for developmental toxicity of at least 450 mg/kg bw/day.

In a two generation study with m-cresol the NOAEL for developmental toxicity for F1 and F2 pups, litter size, sex ratio, and litter viability was unaffected by treatment. In F1 the female pups had reduced body weights in the highest dose tested (450 mg/kg bw/day), but pup survival was not affected. In F2, pup body weight, pup body weight gain and pup lactational index were reduced and pup mortality was increased at the highest dose. Thus the NOAEL (developmental) was 175 mg/kg bw/day.

A developmental toxicity study in rabbits according to TSCA Health Effect Guidelines for Specific Organ/Tissue Toxicity - Developmental Toxicity (EPA 1984, 1987) is available for m-cresol (CMA, 1988h). Administration of m-cresol by gavage to time-pregnant New Zealand White rabbits during organogenesis (gestation day 6 - 18) at 0, 5, 50 or 100 mg/kg bw/day caused clinical signs of toxicity including audible respiration and ocular discharge from 50 mg/kg bw/day onwards. Therefore, a NOAEL for maternal toxicity of 5 mg/kg bw/day was derived. No developmental effects were seen at any dosage employed leading to a NOAEL for developmental toxicity of 100 mg/kg bw/day.

Conclusion:

The maternal NOAEL in the developmental toxicity studies with rats is 175 mg/kg bw/ day and for rabbits 5 mg/kg bw/day. Slight fetotoxicity (non-adverse) was observed for o- and p-cresol in rats whereas m-cresol did not show any effects regarding fetotoxicity resulting in a NOAEL (developmental, rats) of 450 mg/kg bw/day. In rabbits, only o-cresol showed slight non-adverse developmental effects wheras m- and p-cresol did not show any developmental effects resulting in a NOAEL (developmental, rabbit) of 100 mg/kg bw/day. However, as there are no data available on effects on developmental toxicity for Tar acids, Xylenol fraction (CAS 84989-06-0) a weight-of-evidence approach was conducted taking into account all available data on the source substances and Tar acids, Xylenol fraction (CAS 84989-06-0) was therefore not considered to be toxic to reproduction.

Toxicity to reproduction: other studies

Description of key information

In absence of experimental data on Tar acids, Xylenol fraction (CAS 84989-06-0) an analogue read-across approach was conducted:

WoE - o-cresol (RL1; according to OECD 408 and GLP, rat): NOAEL(general toxicity, males): 247 mg/kg bw/day; NOAEL(general toxicity, females): 256 mg/kg bw/day; NOAEL(reproduction; males): 2028 mg/kg bw/day; NOAEL (reproduction, females): 2024 mg/kg bw/day;

WoE - o-cresol (RL1, according to OECD 408 and GLP, mouse): NOAEL(general toxicity, males): 199 mg/kg bw/day; NOAEL(general toxicity, females): 237 mg/kg bw/day; NOAEL(reproduction; males): 2733 mg/kg bw/day; NOAEL (reproduction, females): 1633 mg/kg bw/day;

Link to relevant study records

Referenceopen allclose all

Endpoint:
toxicity to reproduction: other studies
Type of information:
read-across from supporting substance (structural analogue or surrogate)
Remarks:
Summary of available data used for the endpoint assessment of the target substance
Adequacy of study:
key study
Justification for type of information:
refer to analogue justification provided in IUCLID section 13
Reason / purpose:
read-across source
Reason / purpose:
read-across source
Key result
Dose descriptor:
NOAEL
Remarks:
general toxicity, rat
Effect level:
3 750 ppm (nominal)
Based on:
test mat.
Sex:
male/female
Basis for effect level:
other: >= 7500 ppm: increased relative liver and kidney weights
Remarks on result:
other: males ca. 247 mg/kg bw/day; females ca. 256 mg/kg bw/day; Source, CAS 95-48-7, o-cresol, NTP, 1991
Key result
Dose descriptor:
NOAEL
Remarks:
reproduction, rat
Effect level:
30 000 ppm (nominal)
Based on:
test mat.
Sex:
male/female
Basis for effect level:
other: Males: Reproductive organ weights and Spermatozoal measurements (including % motility) and concentration showed no difference to the respective control values; Females: No significant changes in the medium oestrous cycle length.
Remarks on result:
other: males ca. 2028 mg/kg bw/day; females ca. 2024 mg/kg bw/day; Source, CAS 95-48-7, o-cresol, NTP, 1991
Key result
Dose descriptor:
NOAEL
Remarks:
general toxicity, mouse
Effect level:
1 250 ppm (nominal)
Based on:
test mat.
Sex:
male/female
Basis for effect level:
other: >=2500 ppm: increased relative and absolute liver and kidney weights
Remarks on result:
other: corresponds to 199 (males) and 237 mg/kg bw/d (females), respectively; Source, CAS 95-58-7, o-cresol, NTP, 1991
Key result
Dose descriptor:
NOAEL
Remarks:
reproduction, mouse
Effect level:
20 000 ppm (nominal)
Based on:
test mat.
Sex:
male/female
Basis for effect level:
other:
Remarks on result:
other: corresponds to 2733 (males) and 1663 mg/kg bw/d (females), respectively; Source, CAS 95-58-7, o-cresol, NTP, 1991
Conclusions:
No effects on reproductive parameters were observed in sub-chronic studies in rats and mice with the source substance o-cresol. Similar effects are considered for the target substance as explained in the analogue justification.
Endpoint:
toxicity to reproduction: other studies
Type of information:
experimental study
Adequacy of study:
weight of evidence
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: additional investigations in mice within a 90 day study
Reason / purpose:
reference to same study
Principles of method if other than guideline:
Subchronic toxicity study with determination of sperm motility and concentration in males and length of oestrus cycle and vaginal cytology following repeated dose according EPA OPP 82-1. For details on test method and general toxicity please refer to 7.5.1.
GLP compliance:
yes
Type of method:
in vivo
Species:
mouse
Strain:
B6C3F1
Sex:
male/female
Route of administration:
oral: feed
Vehicle:
unchanged (no vehicle)
Duration of treatment / exposure:
90 d
Frequency of treatment:
daily
Dose / conc.:
1 250 ppm (nominal)
Dose / conc.:
2 500 ppm (nominal)
Dose / conc.:
5 000 ppm (nominal)
Dose / conc.:
10 000 ppm (nominal)
Dose / conc.:
20 000 ppm (nominal)
Control animals:
yes, concurrent no treatment
Key result
Dose descriptor:
NOAEL
Remarks:
general toxicity
Effect level:
1 250 ppm (nominal)
Based on:
test mat.
Sex:
male/female
Basis for effect level:
other: >=2500 ppm: increased relative and absolute liver and kidney weights
Remarks on result:
other: corresponds to 199 (males) and 237 mg/kg bw/d (females), respectively
Key result
Dose descriptor:
NOAEL
Remarks:
reproduction
Effect level:
20 000 ppm (nominal)
Based on:
test mat.
Sex:
male/female
Basis for effect level:
other:
Remarks on result:
other: corresponds to 2733 (males) and 1663 mg/kg bw/d (females), respectively

Male:

Reproductive organ weights (R. testicle and R. epididymidis) showed no difference to the respective controls; epididymal tail weight was significantly reduced when compared to the respective control at the high dose.

Spermatogonial measurements revealed no findings.

 

Female:

Mean estrous cycle length was significantly prolonged at 20000 ppm.

Conclusions:
No effects on reproduction were observed.
Endpoint:
toxicity to reproduction: other studies
Type of information:
experimental study
Adequacy of study:
weight of evidence
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: additional investigations in rats within a 90 day study
Reason / purpose:
reference to same study
Principles of method if other than guideline:
Subchronic toxicity study in rats with determination of sperm motility and concentration in males and length of oestrus cycle and vaginal cytology following repeated dose according EPA OPP 82-1. For further details on method and general toxicity please refer to 7.5.1.
GLP compliance:
yes
Type of method:
in vivo
Species:
rat
Strain:
Fischer 344
Sex:
male/female
Route of administration:
oral: feed
Vehicle:
unchanged (no vehicle)
Duration of treatment / exposure:
90 d
Frequency of treatment:
daily
Dose / conc.:
1 880 ppm (nominal)
Dose / conc.:
7 500 ppm (nominal)
Dose / conc.:
30 000 ppm (nominal)
Control animals:
yes, concurrent vehicle
Key result
Dose descriptor:
NOAEL
Remarks:
general toxicity
Effect level:
3 750 ppm (nominal)
Based on:
test mat.
Sex:
male/female
Basis for effect level:
other: >= 7500 ppm: increased relative liver and kidney weights
Remarks on result:
other: males ca. 247 mg/kg bw/day; females ca. 256 mg/kg bw/day
Key result
Dose descriptor:
NOAEL
Remarks:
reproduction
Effect level:
30 000 ppm (nominal)
Based on:
test mat.
Sex:
male/female
Basis for effect level:
other: Males: Reproductive organ weights and Spermatozoal measurements (including % motility) and concentration showed no difference to the respective control values; Females: No significant changes in the medium oestrous cycle length.
Remarks on result:
other: males ca. 2028 mg/kg bw/day; females ca. 2024 mg/kg bw/day

Males: Reproductive organ weights (R. testicle, R. epididymis, R. epididymis tail) and Spermatozoal measurements (including % motility) and concentration showed no difference to the

respective control values

Females: >= 7500 ppm: Medium oestrous cycle length was significant increased, especially at 7500 ppm in 2/10 females the length exceeded 7 days and at 30000 ppm in 2/10 females the

oestrous cycle length was not determined or exceeded 7 days. However, these changes were not statistically significant.

Conclusions:
No effects on reprotoxicity was observed.
Additional information

These additional information on reproduction paramaters examined in 90-day studies are discussed above under "Additional information for fertility effects".

Justification for classification or non-classification

Based on all available information (weight-of-evidence), following an analogue read-across approach, for Tar acids, Xylenol fraction (CAS 84989-06-0) no classification for toxicity to reproduction as well as effects on or via lactation is required according to Regulation (EC) No 1272/2008.