Toluenesulphonamide

Endpoint summary

Key value for chemical safety assessment

Effects on fertility

Link to relevant study records

Reference

Endpoint:

two-generation reproductive toxicity

Remarks:

based on test type (migrated information)

Type of information:

migrated information: read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

key study

Study period:

2006 October 19 - 2007 July 02

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Study performed according to OECD and EU guidelines and according to GLP principles.

Qualifier:

according to guideline

Guideline:

OECD Guideline 416 (Two-Generation Reproduction Toxicity Study)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method B.35 (Two-Generation Reproduction Toxicity Test)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EPA OPPTS 870.3800 (Reproduction and Fertility Effects)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Limit test:

no

Species:

rat

Strain:

Wistar

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River Deutschland, Sulzfeld, Germany
- Age at study initiation: (P) 5-6 wks; (F1) 3 wks
- Housing: Pre-mating: Animals were housed in groups of 4 animals/sex/cage in Macrolon plastic cages.
Mating: Females were caged together with males on a one-to-one-basis in Macrolon plastic cages
Post-mating: Males were housed in groups of 4 animals/sex/cage in Macrolon plastic cages. Females were individually housed in Macrolon plastic cages.
- Diet (e.g. ad libitum): ad libitum
- Water (e.g. ad libitum): ad libitum
- Acclimation period: at least 5 days.

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 17.6-24.2
- Humidity (%): 27-95
- Air changes (per hr): 15
- Photoperiod (hrs dark / hrs light): 12/12

Route of administration:

oral: feed

Vehicle:

unchanged (no vehicle)

Details on exposure:

DIET PREPARATION
- Rate of preparation of diet (frequency): Diets were prepared for one week during the first week of study and every two weeks from Week 2 of study onwards. For the last weeks of the study, diets were prepared for a maximum of 36 days.
- Mixing appropriate amounts with Standard powder rodent diet

Details on mating procedure:

- M/F ratio per cage: 1/1
- Length of cohabitation: 2 weeks
- Proof of pregnancy: vaginal plug / sperm in vaginal smear referred to as day 0 of pregnancy
- After 10 days of unsuccessful pairing replacement of first male by another male with proven fertility.
- After successful mating each pregnant female was caged: individually

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

Sampling and analysis of diet preparations were performed on four occasions (week 1, 11, 22 and 33) according to the following scheme:
Group 1: accuracy (middle position of container)
Group 2: accuracy and homogeneity (top, middle and bottom position of container)
Group 3: accuracy (middle position of container)
Group 4: accuracy and homogeneity (top, middle and bottom position of container)

Duration of treatment / exposure:

F0-generation: 10 weeks prior to mating and continuing until euthanasia.
F1-generation (F0-offspring): The F1-generation was potentially exposed to the test substance in utero, through nursing during lactation and directly following weaning. After weaning, pups were treated for a minimum of 10 weeks prior to mating and continuing until euthanasia.
F2-generation (F1-offspring): The F2-generation was potentially exposed to the test substance in utero and through nursing during lactation.

Frequency of treatment:

Ad libitum

Details on study schedule:

- F1 parental animals not mated until 70 days after selected from the F1 litters.
- Selection of parents from F1 generation when pups were 21 days of age.

Remarks:

Doses / Concentrations:
1000 ppm
Basis:
nominal in diet

Remarks:

Doses / Concentrations:
3000 ppm
Basis:
nominal in diet

Remarks:

Doses / Concentrations:
10000
Basis:
nominal in diet

No. of animals per sex per dose:

24

Control animals:

yes, plain diet

Details on study design:

- Dose selection rationale: based on results of a 28-day toxicity study in Wistar Han rats at dose levels of 0, 1000, 5000 and 25000 ppm.

Parental animals: Observations and examinations:

CAGE SIDE OBSERVATIONS: Yes
- Time schedule: At least twice daily.
- Cage side observations: mortality, viability.

DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule: At least once daily.

BODY WEIGHT: Yes
- Time schedule for examinations: Males and females were weighed on the first day of exposure and weekly thereafter. Mated females were weighed on days 0, 4, 7, 11, 14, 17 and 20 of gestation, and during lactation on days 1, 4, 7, 14 and 21.

FOOD CONSUMPTION AND COMPOUND INTAKE (if feeding study):
- Food consumption for each animal determined and mean daily diet consumption calculated as g food/kg body weight/day: Yes
- Compound intake calculated as time-weighted averages from the consumption and body weight gain data: Yes

WATER CONSUMPTION : Yes
- Time schedule for examinations: subjective appraisal.

Oestrous cyclicity (parental animals):

Daily over a period of 3 weeks prior to pairing and throughout cohabitation

Sperm parameters (parental animals):

testis weight, epididymis weight, enumeration of homogenisation-resistant spermatids in testes and epididymis, enumeration of cauda epididymal sperm reserve, sperm motility, sperm morphology.

Litter observations:

PARAMETERS EXAMINED
number and sex of pups
stillbirths
live births
presence of gross anomalies
weight gain
physical or behavioural abnormalities
The day of vaginal opening or balanopreputial separation for F1-weanlings selected for mating. As a slightly delayed balanopreputial separation and vaginal opening for high dose F1-weanlings was observed, ano-genital distance was measured on day 1 of lactation for all F2-pups.

GROSS EXAMINATION OF DEAD PUPS:
yes, for external and internal abnormalities; possible cause of death was determined for pups born or found dead.

Postmortem examinations (parental animals):

SACRIFICE
- Male animals: All surviving animals as soon as possible after the last litters in each generation were produced.
- Maternal animals: All surviving animals on day 21 post partum or shortly thereafter. Females showing no evidence of copulation were killed approximately 21 days after the last day of the mating period.

GROSS NECROPSY
- Gross necropsy consisted of external and internal examinations of the cranial, thoracic and abdominal tissues and organs, with special attention being paid to the reproductive organs.

HISTOPATHOLOGY / ORGAN WEIGHTS
The following tissues were prepared for microscopic examination: cervix, coagulation gland, epididymides, ovaries, prostate gland, seminal vesicles, testes, uterus, vagina, all gross lesions.
The following organs were weighed: Adrenal glands, Brain, Epididymides, Kidneys, Liver, Ovaries, Pituitary gland, Prostate, Seminal vesicles, Spleen,
Testes, Thyroid, Uterus

Postmortem examinations (offspring):

SACRIFICE
- The F1 offspring not selected as parental animals and all F2 offspring were sacrificed at day 21 post partum or shortly thereafter.
- These animals were subjected to postmortem examinations (macroscopic and microscopic examination) as follows:
Vagina, uterus, ovaries, testis, epididymis, seminal vesicle, prostate, coagulating gland

GROSS NECROPSY
- Gross necropsy consisted of external examination of the cranium, and macroscopic examination of the thoracic and abdominal tissues and organs with emphasis on developmental morphology.

HISTOPATHOLOGY / ORGAN WEIGTHS
The following tissues were prepared for microscopic examination: Vagina, uterus, ovaries, testis, epididymis, seminal vesicle, prostate, coagulating gland
The following tissues were weighed: brain, spleen, thymus

Statistics:

The following statistical methods were used to analyse the data:
- If the variables could be assumed to follow a normal distribution, the Dunnett-test (Dunnett, 1955) (many-to-one t-test) based on a pooled variance estimate was applied for the comparison of the treated groups and the control groups for each sex.
- The Steel-test (Miller, 1981) (many-to-one rank test) was applied if the data could not be assumed to follow a normal distribution.
- The Fisher Exact-test (Fisher 1950) was applied to frequency data.

All tests were two-sided and in all cases p < 0.05 were accepted as the lowest level of significance.

Reproductive indices:

Percentage mating: Number of females mated x 100 / Number of females paired
Fertility index: Number of pregnant females x 100 / Number of females paired
Conception rate: Number of pregnant females x 100 / Number of females mated
Gestation index: Number of females bearing live pups x 100 / Number of pregnant females
Duration of gestation: Number of days between confirmation of mating and the beginning of parturition

Offspring viability indices:

Percentage live males at First Litter Check: Number of live male pups at First Litter Check x 100 / Number of live pups at First Litter Check
Percentage live females at First Litter Check: Number of live female pups at First Litter Check x 100 / Number of live pups at First Litter Check
Percentage of postnatal loss days 0-4 post partum: Number of dead pups on day 4 post partum x 100 / Number of live pups at First Litter Check
Percentage of breeding loss day 5 until weaning: Number of dead pups between days 5 and 21 post partum x 100 / Number of live pups on day 4 post partum
Percentage live males at weaning: Number of live male pups on day 21 post partum x 100 / Number of live pups on day 21 post partum
Percentage live females at weaning: Number of live female pups on day 21 post partum x 100 / Number of live pups on day 21 post partum
Viability index: Number of live pups on day 4 post partum x 100 / Number of pups born alive
Weaning index: Number of live pups on day 21 post partum x 100 / Number of live pups on day 4 post partum

Clinical signs:

no effects observed

Body weight and weight changes:

effects observed, treatment-related

Food consumption and compound intake (if feeding study):

effects observed, treatment-related

Organ weight findings including organ / body weight ratios:

effects observed, treatment-related

Histopathological findings: non-neoplastic:

no effects observed

Other effects:

no effects observed

Reproductive function: oestrous cycle:

no effects observed

Reproductive function: sperm measures:

no effects observed

Reproductive performance:

no effects observed

BODY WEIGHT AND FOOD CONSUMPTION (PARENTAL ANIMALS)
ORGAN WEIGHTS (PARENTAL ANIMALS)
Males P generation:
At 3000 ppm:
Decreased body weights and body weight gain. Terminal body weights at necropsy (92% of control) were decreased which resulted in relative organ weight changes for the brain and kidneys (105% and 110% of control, respectively).
At 10000 ppm:
Decreased body weights and body weight gain. Terminal body weights at necropsy (91% of control) were decreased which resulted in relative organ weight changes for the brain, liver, kidneys and seminal vesicles (108%, 108%, 118% and 116% of control, respectively).

Females P generation:
At 3000 ppm:
Decreased body weights and body weight gain. Terminal body weights at necropsy (94% of control) were decreased which resulted in relative organ weight changes for the brain (107% of control).
At 10000 ppm:
Decreased body weights and body weight gain. Terminal body weights at necropsy (91% of control) were decreased which resulted in relative organ weight changes for the brain, kidneys, adrenals and spleen (109%, 121%, 112% and 110% of control, respectively).

Males F1 generation:
At 3000 ppm:
Decreased body weights and body weight gain. Terminal body weights at necropsy (93% of control) were decreased which resulted in absolute organ weight changes for the spleen (90% of control) and relative organ weight changes for the brain (108% of control).
At 10000 ppm:
Decreased body weights and body weight gain. Terminal body weights at necropsy (87% of control) were decreased which resulted in absolute organ weight changes for the brain, liver, and spleen (95%, 89% and 89% of control, respectively), and relative organ weight changes for the brain, kidneys, seminal vesicles, testes and prostate (108%, 111%, 124%, 109% and 118% of control, respectively).

Females F1 generation:
At 3000 ppm:
Decreased body weights, body weight gain and terminal body weights at necropsy (93% of control).
At 10000 ppm:
Decreased body weights and body weight gain. Decreased food consumption during the last week of pregnancy. Terminal body weights at necropsy (85% of control) were decreased which resulted in absolute organ weight changes for the brain (93% of control) and relative organ weight changes for the brain, kidneys, adrenals, spleen and pituitary gland (110%, 118%, 112%, 113% and 120% of control, respectively).

Dose descriptor:

NOAEL

Remarks:

parental

Effect level:

1 000 ppm (nominal)

Sex:

male/female

Basis for effect level:

other: Corresponds to 52-78 mg/kg bw/day for males and 75-161 mg/kg bw/day for females.

Remarks on result:

other: Generation: P and F1 (migrated information)

Dose descriptor:

NOAEL

Remarks:

developmental

Effect level:

3 000 ppm (nominal)

Sex:

male/female

Basis for effect level:

other: Corresponds to 165-237 mg/kg bw/day for males and 232-499 mg/kg bw/day for females.

Remarks on result:

other: Generation: F1 and F2 (migrated information)

Dose descriptor:

NOAEL

Remarks:

reproduction and breeding

Effect level:

10 000 ppm (nominal)

Sex:

male/female

Basis for effect level:

other: Corresponds to 566-832 mg/kg bw/day for males and 733-1631 mg/kg bw/day for females.

Remarks on result:

other: Generation: P and F1 (migrated information)

Dose descriptor:

LOAEL

Remarks:

parental

Effect level:

3 000 ppm (nominal)

Sex:

male/female

Basis for effect level:

other: Based on decreased body weights and body weight gain, and due to this organ weight changes.

Remarks on result:

other: Generation: P and F1 (migrated information)

Dose descriptor:

LOAEL

Remarks:

developmental

Effect level:

10 000 ppm (nominal)

Sex:

male/female

Basis for effect level:

other: Based on decreased body weights and body weight gain, and due to this organ weight changes.

Remarks on result:

other: Generation: F1 and F2 (migrated information)

Clinical signs:

no effects observed

Mortality / viability:

no mortality observed

Body weight and weight changes:

effects observed, treatment-related

Sexual maturation:

no effects observed

Organ weight findings including organ / body weight ratios:

effects observed, treatment-related

Gross pathological findings:

no effects observed

Histopathological findings:

no effects observed

BODY WEIGHT (OFFSPRING)
ORGAN WEIGHTS (OFFSPRING)
Male pups F1 generation:
At 10000 ppm:
Lower body weights for pups (terminal body weight at necropsy was 85% of control) which resulted in absolute organ weight changes for the brain, spleen and thymus (95%, 78% and 74% of control, respectively), relative organ weight changes for the brain (111% of control), and a delay in balanopreputial separation (108% of control).

Female pups F1 generation:
At 10000 ppm:
Lower body weights for pups (terminal body weight at necropsy was 84% of control) which resulted in absolute organ weight changes for the brain, spleen and thymus (94%, 78% and 73% of control, respectively), relative organ weight changes for the brain (112% of control), and a delay in vaginal opening (114% of control).

Male pups F2 generation:
At 10000 ppm:
Lower body weights for pups (terminal body weight at necropsy was 81% of control) which resulted in absolute organ weight changes for the brain, spleen and thymus (95%, 75% and 70% of control, respectively) and relative organ weight changes for the brain (117% of control).

Female pups F2 generation:
At 10000 ppm:
Lower body weights for pups (terminal body weight at necropsy was 82% of control) which resulted in absolute organ weight changes for the spleen and thymus (76% and 73% of control, respectively) and relative organ weight changes for the brain and thymus (118% and 90% of control, respectively).

Reproductive effects observed:

not specified

Table 1. Mean test article intake when corrected for mean value of recovery

Nominal dose	1000 ppm	3000 ppm	10000 ppm
Mean value of recovery	930 ppm	2820 ppm	9600 ppm
MALES F0
Pre mating	75	236	787
Post mating	52	165	568
FEMALES F0
Premating	85	264	862
Postcoitum	75	238	739
Lactation	161	499	1631
MALES F1
Premating	78	237	832
Post mating	53	165	566
FEMALES F1
Premating	86	264	887
Postcoitum	75	232	733
Lactation	160	487	1582

Table 2. Reproductive toxicity

Dose (ppm)

0

1000

3000

10000

dr

m

f

m

f

m

f

m

f

F0 animals

Mortality

no treatment-related findings

Clinical signs

no treatment-related findings

Body weight gain

dc

dc

dc

dc

mf

Food consumption

no treatment-related findings

Mating/fertility/gestation

no treatment-related findings

Oestrus cycle

no treatment-related findings

Sperm evaluation

no treatment-related findings

Organ weight

- terminal body weight

dc (94%)

dc (92%)

dc (91%)

dc (91%)

- brain

ic^r (107%)

ic^r (105%)

ic^r (109%)

ic^r (108%)

- liver

ic^r (108%)

- kidneys

ic^r (110%)

ic^r (121%)

ic^r (118%)

f

- adrenals

ic^r (112%)

- spleen

ic^r (110%)

- seminal vesicles

ic^r (116%)

Pathology

Macroscopy

no treatment-related findings

Microscopy

no treatment-related findings

F1 pups

Litter size

no treatment-related findings

Post implantation loss

no treatment-related findings

Live birth index

no treatment-related findings

Viability index

no treatment-related findings

Lactation index

no treatment-related findings

Sex ratio

no treatment-related findings

Clinical signs

no treatment-related findings

Body weight

dc

dc

Sexual maturation

ic

ic

Pup development

no treatment-related findings

Organ weight

- terminal body weight

dc (84%)

dc (85%)

- brain

dc^a (94%) ic^r (112%)

dc^a (95%) ic^r (111%)

- spleen

dc^a (78%)

dc^a (78%)

- thymus

dc^a (73%)

dc^a (74%)

Pathology

Macroscopy

no treatment-related findings

Microscopy

no treatment-related findings

F1 animals

Mortality

no treatment-related findings

Clinical signs

no treatment-related findings

Body weight gain

dc

dc

dc

dc

mf

Food consumption

dc

Mating/fertility/gestation

no treatment-related findings

Oestrus cycle

no treatment-related findings

Sperm evaluation

no treatment-related findings

Organ weight

- terminal body weight

dc (93%)

dc (93%)

dc (87%)

dc (85%)

mf

- brain

ic^r (108%)

dc^a (95%) ic^r (108%)

dc^a (93%) ic^r (110%)

- pituitary

ic^r (120%)

- liver

dc^a (89%)

- kidneys

ic^r (111%)

ic^r (118%)

- adrenals

ic^r (112%)

- spleen

dc^a (90%)

dc^a (89%)

ic^r (113%)

- testes

ic^r (109%)

- prostate

ic^r (118%)

- seminal vesicles

ic^r (124%)

Pathology

Macroscopy

no treatment-related findings

Microscopy

no treatment-related findings

F2 pups

Litter size

no treatment-related findings

Post implantation loss

no treatment-related findings

Live birth index

no treatment-related findings

Viability index

no treatment-related findings

Lactation index

no treatment-related findings

Sex ratio

no treatment-related findings

Clinical signs

no treatment-related findings

Body weight

dc

dc

Pup development

no treatment-related findings

Auditory and visual response

not performed

Organ weight

- terminal body weight

dc (81%)

dc (82%)

- brain

dc^a (95%) ic^r (117%)

ic^r (118%)

- spleen

dc^a (75%)

dc^a (76%)

- thymus

dc^a (70%)

dc^a (73%) dc^r (90%)

Pathology

no treatment-related findings

dc/ic     statistically significantly decreased/increased compared to the controls

a/r        absolute/relative organ weight

(%)       relative to control

dr         dose-related

Conclusions:

Parental toxicity was observed for both generations at the mid and high dose groups (3000 and 10000 ppm).
Developmental toxicity was observed for both generations at the high dose group (10000 ppm).
Reproduction and breeding parameters were unaffected for both generations for treatment up to 10000 ppm.
Based on these findings, the definitive parental No Observed Adverse Effect Level (NOAEL) was established as being 1000 ppm.
The definitive development NOAEL was established as being 3000 ppm.
The definitive reproduction and breeding NOAEL was established as being at least 10000 ppm.
When corrected for mean test article intake the NOAEL of 1000 ppm corresponds to 52-78 mg/kg bw/day for males and 75-161 mg/kg bw/day for females, the NOAEL of 3000 ppm corresponds to 165-237 mg/kg bw/day for males and 232-499 mg/kg bw/day for females, and the NOAEL of 10000 ppm corresponds to 566-832 mg/kg bw/day for males and 733-1631 mg/kg bw/day for females.

Executive summary:

A two-generation reproduction toxicity study of p-TSA in rats by dietary administration.

The study was based on the following guidelines:

- OECD 416, Two-Generation Reproduction Toxicity Study, January 2001.

- OPPTS 870.3800, Reproduction and Fertility Effects, August 1998.

- EC, Commission directive 2004/73/EC, B.35:"Two-generation reproduction toxicity study", April 2004.

 

After acclimatisation, male and female Wistar rats of the Fe-generation were exposed by dietary inclusion to graduated doses of the test substance. The dose levels for the F0-generation and for the F1-generation were 1000, 3000 and 10000 ppm.

At regular intervals, prepared diets were analysed for accuracy of preparation and homogeneity.

F0-males and F0-females were exposed to the test substance 10 weeks prior to mating and exposure ended at termination. F0-females were allowed to produce and rear a litter until day 21 of lactation. On day 4 of lactation litters were reduced in size to eight pups by random culling of F1-pups. After weaning, one F1-male and one F1-female of each litter were selected for cross mating with a pup of another litter of the same dose group to produce a F2-generation. Mating commenced at least 10 weeks after weaning. F1-offspring selected for mating were dosed from weaning until they were killed after weaning of the F2-offspring on day 21 of lactation. On day 4 of lactation a selection of F2-pups was culled. Pups of the F2-offspring were killed shortly after weaning.

 

All animals were subjected to daily clinical observation. Body weight and food consumption were measured over the treatment period. The regularity and duration of the estrous cycle was examined. At necropsy, macroscopic observations and organ weights were recorded. Sperm morphology, motility and count were assessed. A histopathological examination was performed on all reproduction organs and tissues. Reproduction parameters, breeding data and pup development were assessed. Blood samples were collection from F1 females (10/group) for possible measurement of thyroid hormones. These samples were discarded without analyses.

 

RESULTS

Chemical analysis revealed that the diets were prepared properly and were considered to be homogeneous.

 

The following changes were considered to be related to treatment:

F0-GENERATION

at 1000 ppm (group 2):

•      No treatment-related findings.

 

at 3000 ppm (group 3):

•      Decreased body weights and body weight gain.
Terminal body weights at necropsy were decreased which resulted in relative organ weight changes for the brain and kidneys.

 

at 10000 ppm (group 4):

•      Decreased body weights and body weight gain.
Terminal body weights at necropsy were decreased which resulted in relative organ weight changes for the brain, liver, kidneys, seminal vesicles, adrenals, and spleen.
Lower body weights for male and female pups which resulted in organ weight changes for the brain, spleen and thymus and a delay in vaginal opening and balanopreputial separation.

 

F1-GENERATION

at1000ppm (group2):

•      No treatment-related findings.

 

at3000ppm (group3):

•      Decreased body weights and body weight gain.
Terminal body weights at necropsy were decreased which resulted in organ weight changes for the brain and spleen.

 

at10000ppm (group4):

•      Decreased body weights and body weight gain.
Decreased food consumption for females during the last week of pregnancy.
Terminal body weights at necropsy were decreased which resulted in organ weight changes for the brain, liver, kidneys, seminal vesicles, adrenals, spleen, testes, prostate, and pituitary gland. Lower body weights for male and female pups which resulted in organ weight changes for the brain, spleen and thymus.

 

CONCLUSION

Treatment with p-TSA by dietary inclusion in male and female Wistar rats at dose levels of1000, 3000 and 10000 ppm revealed Fo-and F1-parental toxicity at3000and10000ppm and developmental toxicity (related to decreased body weights of dams) at 10000ppm.

Reproduction and breeding parameters were unaffected for both generations for treatment up to 10000 ppm.

 

Based on these findings, the definitive parental No Observed Adverse Effect Level (NOAEL) was established as being 1000 ppm.

The definitive development NOAEL was established as being 3000 ppm.

The definitive reproduction and breeding NOAEL was established as being at least 10000 ppm.

 

When corrected for mean test article intake the NOAEL of 1000 ppm corresponds to 52 -78 mg/kg bw/day for males and 75-161mg/kg bw/day for females, the NOAEL of 3000 ppm corresponds to 165-237 mg/kg bw/day for males and 232 -499 mg/kg bw/day for females, and the NOAEL of 10000 ppm corresponds to 566 -832 mg/kg bw/day for males and 733 -1631 mg/kg bw/day for females.

Effect on fertility: via oral route

Endpoint conclusion:

adverse effect observed

Dose descriptor:

NOAEL

165 mg/kg bw/day

Study duration:

subchronic

Species:

rat

Quality of whole database:

There are several high quality studies available for both p-TSA and o-TSA (OECD 422 screening studies, and a two-generation study). The two-generation study is selected as the most relevant for the evaluation of reproduction toxicity. The selected NOAEL represents the lowest reproduction/development NOAEL of 3000 ppm (corresponding to 165-237 mg/kg bw/day in males and 232 -499 mg/kg bw/day in females)

Effect on fertility: via inhalation route

Endpoint conclusion:

no study available

Effect on fertility: via dermal route

Endpoint conclusion:

no study available

Additional information

o/p-TSA consists of a mixture of p-TSA and o-TSA, and the evaluation for repeated dose toxicity is therefore also applicable to o/p-TSA. There are various studies available for both p-TSA and o-TSA of which the selected key studies are selected for the evaluation of o/p-TSA.( See document in support of cross-reading between these substances and o/p-TSA.)

The following high quality studies are available for both p-TSA and o-TSA: An OECD 422 screening study for both and a two-generation study on p-TSA.

 

70-55-3, Toxicity to reproduction 2-gen rat, NOTOX 474064, 2007

A full two-generation study in rats has been performed under GLP and according to OECD 416 with p-TSA administration by dietary admixture at levels of 0, 1000, 3000 and 10,000 ppm.

All animals were subjected to daily clinical observation. Body weight and food consumption were measured over the treatment period. The regularity and duration of the estrous cycle was examined. At necropsy, macroscopic observations and organ weights were recorded. Sperm morphology, motility and count were assessed. A histopathological examination was performed on all reproduction organs and tissues. Reproduction parameters, breeding data and pup development were assessed.

No effects were observed at 1000 ppm. At 3000 ppmterminal body weights of F0 and F1 parent animals at necropsy were decreased which resulted in relative organ weight changes for the brain and kidneys.

At 10,000 ppm the terminal body weights at necropsy were decreased which resulted in relative organ weight changes for the brain, liver, kidneys, seminal vesicles, adrenals, and spleen. In the F1 generation also testes, prostate, and pituitary gland showed relative organ weight changes. Also lower body weights for male and female pups were observed which resulted in organ weight changes for the brain, spleen and thymus and a delay in vaginal opening and balano-preputial separation in F1 animals.

Based on these findings thestudy concluded upon

- NOAEL parental of1000ppm (males52 -78 mg/kg bw/day; females75-161 mg/kg bw/day).

- NOAEL developmental toxicity of3000ppm(males 165-237 mg/kg bw/day; females232 -499 mg/kg bw/day)

- NOAEL reproduction and breeding of at least 10000ppm (males 566 -832 mg/kg bw/day; females 733 -1631 mg/kg bw/day)

 

70-55-3, Toxicity to reproduction, MHW Japan, 1994

OECD 422, Combined Repeat Dose and Reproductive/Developmental Toxicity Screening Test in rat by gavage under GLP. Dose levels: 0 (vehicle, 5% Arabic gum), 120, 300, 750 mg/kg/day, with 13 animals per dose group per sex. Dosing period: Females, from 14 days before mating to day 3 of lactation. Males 42 days.

Mating performance and fertility were not affected by the test compound. Two of 10 females in the high-dose group showed signs of difficult delivery and all of their offspring died by day 3 of lactation.

Reproduction parameters (i.e., duration of gestation, numbers of corpora lutea, implantations and resorptions, litter size, and sex distribution) were comparable among all four groups, including the control. However, significant decreases in both survival rate and body weight of newborns on day 0 of lactation were observed in the high-dose group. Morphological observations of offspring revealed no teratogenic effects of 4-methylbenzenesulfonamide.

NOEL for P generation: 300 mg/kg/day

NOEL for F1 generation: 300 mg/kg/day

 

88-19-7, Toxicity to reproduction, MHW Japan, 1999

OECD 422, Combined Repeat Dose and Reproductive/Developmental Toxicity Screening Test in rat by gavage under GLP. Dose levels: 0 (vehicle, 5% CMC), 20, 100, 500 mg/kg/day, with 13 animals per dose group per sex. Dosing period: Females, from 14 days before mating to day 3 of lactation. Males were dosed for 42 days.

Mating performance and fertility were not affected by the test compound.

Clinical signs were observed such as decreased locomotor activity and prone position, and histopathological change in liver seen from 100 mg/kg. At 500 mg/kgbw severe toxicity was observed with three females died and two females were sacrificed in moribund condition during pre-mating period.

Reproduction parameters (i.e., duration of gestation, numbers of corpora lutea, implantations and resorptions, litter size, and sex distribution) were comparable among all four groups, including the control. However, significant decreases in body weight of newborns on day 0 and 4 of lactation were observed in the high-dose group. Morphological observations of offspring revealed no teratogenic effects of 4-methylbenzenesulfonamide.

NOEL for P generation: 20 mg/kg/day

NOEL for F1 generation: 100 mg/kg/day

 

These results were later confirmed in an additional reproduction screening study (OECD 421) also performed by Hatano Research Institute, Food and Drug Safety Center in Japan (available at http://dra4.nihs.go.jp/mhlw_data/jsp/SearchPageENG.jsp, not included in this dossier). In this study 13 rats(Crj:CD(SD)IGS)/sex/dose were treated with o-TSA (99.95 wt%) at dose levels of 0 (vehicle: 0.5% CMC solution), 4, 20 and 100 mg/kgbw/d by gavage. Males were treated for 48 days, and females until day 3 of lactation. In the males testis and epididymis weights were weighted and histologically examined.

There were no effects observed in reproductive parameters as oestrous cycle, fertility and mating, and gestation period. There were some findings in testis and depididymis in some animals of the control, the 4 mg and the 100 mg dose groups, involving atrophy of testis and of the seminiferous tubules with lower number of germ cells and multinucleated giant cells, hyperplasia of Leydig cells, cell debris in lumen epididymis and decreased sperm in epididymis. There was no significant difference between the treated groups and control.

No effects were observed in viability and body weight in the offspring.

Based on these observations the NOAEL for reproduction toxicity was set at 100 mg/kgbw/d.

 

In conclusion, the available studies indicate that there are no effects on reproduction parameters consisting of mating, fertility and conception indices, precoital time, number of corpora lutea and implantation sites, gestation index and duration, parturition, maternal care, sex ratio and early postnatal pup development (mortality, clinical signs, body weights and macroscopy). Also no adverse effects on reproductive organs were identified.

Short description of key information:
Available studies do not indicate a specific concern regarding reproduction toxicity. Reproductive effects that have been observed at highest dose levels can be attributed to deteriorating parental condition as indicated by the lower body weight, and subsequent lower body weight of the pups. The selected NOAEL represents the lowest reproduction/development NOAEL of 3000 ppm from the available 2-generation study (corresponding to 165-237 mg/kg bw/day in males and 232 -499 mg/kg bw/day in females).

Justification for selection of Effect on fertility via oral route:
Only one two-generation study available of high quality.

Effects on developmental toxicity

Description of key information

There is one recent GLP full OECD 414 comparable study available in rats showing no teratogenic effects at toxic dose levels. 

Link to relevant study records

Reference

Endpoint:

developmental toxicity

Type of information:

experimental study

Adequacy of study:

key study

Study period:

18 July 1984 - 15 August 1985

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: see 'Remark'

Remarks:

The study was performed under GLP and according to a method similar to currently internationally accepted guidelines. No verification of dose levels, and no information on food consumption. Exposure from implantation (day 6) through day 15 of gestation instead of from implantation until one day prior to the day of scheduled kill (day 19). Gravid uterus weight was not determined.

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 414 (Prenatal Developmental Toxicity Study)

Principles of method if other than guideline:

Performed in accordance with Series 83-3 of the Environmental Protection Agency Pesticide Assessment Guidelines, Subdivision F, Hazard Evaluation: Human and Domestic Animals, issued November, 1982.
Devations:
- Gravid uterus weight was not determined.
- No verification of dose levels
- No information on food consumption.
- Exposure from implantation (day 6) through day 15 of gestation instead of from implantation until one day prior to the day of scheduled kill (day 19).

GLP compliance:

yes

Limit test:

no

Species:

rat

Strain:

other: COBS CD

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River Breeding Laboratories, Inc., Portage, Michigan, USA
- Age at study initiation: 70 days
- Weight at study initiation: The rats were 118 days old at the time of mating and weighed between 255 and 346g on gestation day 0.
- Fasting period before study: Not applicable
- Housing: The rats were housed individually in suspended wire-mesh cages from receipt until sacrifice except during mating when one male and one female were placed together.
- Diet (e.g. ad libitum): ad libitum, basal Laboratory diet of Purina Certified Rodent Chow #5002
- Water (e.g. ad libitum): ad libitum, tap water
- Acclimation period: 48 day acclimation period


ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22.2 ± 0.35
- Humidity (%): 67 ± 13.4
- Air changes (per hr): no data
- Photoperiod (hrs dark / hrs light): 12/12


IN-LIFE DATES: 18 July 1984 - 15 August 1985

Route of administration:

oral: gavage

Vehicle:

corn oil

Details on exposure:

PREPARATION OF DOSING SOLUTIONS:
The appropriate amount of Santicizer 9 for each group was ground daily with a mortar and pestle, weighed, and suspended i n the vehicle, Mazola corn oil, using a tissue homogenizer. The test material suspension was then transferred to a graduated mixing cylinder and additional vehicle added to yield a sufficient volume of prepared test material.
The suspension was shaken by hand and dispensed into a capped container. Prior to administration, the suspension was stirred using a magnetic stit
bar and stir plate.

VEHICLE
- Justification for use and choice of vehicle (if other than water): no data
- Concentration in vehicle: The test article was prepared at concentrations to permit the administration of dosage levels of 50, 250 and 500 mg/kg/dap at a dosage volume of 10 ml/kg. Individual dosages were determined from individual body weights recorded on gestation days 6, 9 and 12.
- Amount of vehicle (if gavage): max. 10 ml/kg.
- Lot/batch no. (if required): no data
- Purity: no data

Analytical verification of doses or concentrations:

no

Details on mating procedure:

- Impregnation procedure: cohoused
- If cohoused:
- M/F ratio per cage: 1/1
- Length of cohabitation: no data
- After "no data" days of unsuccessful pairing replacement of first male by another male with proven fertility.
- Further matings after two unsuccessful attempts: no data
- 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: none

Duration of treatment / exposure:

single daily dose on days 6 through 15 of gestation

Frequency of treatment:

Single daily dose

Duration of test:

Days 6 through 15 of gestation

Remarks:

Doses / Concentrations:
50, 250, 500 mg/kg bw/day
Basis:
actual ingested

No. of animals per sex per dose:

25

Control animals:

yes, concurrent vehicle

Details on study design:

- Dose selection rationale: range finding study. For summary see "1333-07-9, Developmental toxicity / teratogenicity, Leng, 1985, RS"

Maternal examinations:

CAGE SIDE OBSERVATIONS: Yes
- Time schedule: Prior to treatment, the females were observed twice daily for mortality and overt changes in appearance and behavior. They were
observed twice daily for mortality.

DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule: daily on days 6 through 15 of gestation.

BODY WEIGHT: Yes
- Time schedule for examinations: Individual maternal body weights were recorded on gestation days 0, 6, 9, 12, 16 and 20.


FOOD CONSUMPTION AND COMPOUND INTAKE (if feeding study): No

WATER CONSUMPTION AND COMPOUND INTAKE (if drinking water study): No

POST-MORTEM EXAMINATIONS: Yes
- Sacrifice on gestation day # 20
- Organs examined: The abdominal and thoracic cavities and organs of the dams wesere examined for grossly evident morphological changes and the carcasses discarded. Maternal tissues vere preserved in 10% neutral buffered formalin for possible histopathological examination as deemed necessary by the gross findings.

Ovaries and uterine content:

The ovaries and uterine content was examined after termination: Yes
Examinations included:
- Gravid uterus weight: No
- Number of corpora lutea: Yes
- Number of implantations: Yes
- Number of early resorptions: Yes
- Number of late resorptions: Yes
- Other: The number and location of viable and nonviable fetuses, uteri from females that appeared nongravid uere opened and placed in 10% anmonium sulfide solution for detection of implantations.

Fetal examinations:

- External examinations: Yes: all per litter
- Soft tissue examinations: Yes: half per litter
- Skeletal examinations: Yes: half per litte
- Head examinations: No: included in soft tissue examination, only applicable for non-rodents

Statistics:

All statistical analyses compared the treatment groups with the control group, with the level of significance at P<0.05 and p<0.01. All means were accompanied by standard deviations. Male to female fetal sex ratios and the proportions of litters with malformations were compared using the Chi-square test criterion with Yates' correction for 2 x 2 contingency tables and/or Fisher's exact probability test as described by siegel to judge significance of differences.
The proportions of resorbed and dead fetuses and postimplantation losses were compared by the Mann-Whitney U-test as described by Siegel and Weil to judge significance of differences.
Mean numbers of corpora lutea, total implantations, live fetuses, mean fetal body weights, and mean maternal body weights and body weight changes were compared by analysis of variance (one-way classification). Barelett's test for homogeneity of variances and the appropriate t-test (for equal or unequal variances) as described by Steel and Torrie using Dunnet t 's multiple comparison tables to judge significance of differences.

Historical control data:

Included in the study

Details on maternal toxic effects:

Maternal toxic effects:yes

Details on maternal toxic effects:
Survival was 100% among the control, 50, 250 and 500 mg/kg/day groups. The test article did not produce meaningful differences in maternal appearance and behavior at any dosage level. There was no test item related effect on pregnancy rate.
Clinical signs observed in some groups inclusive of the control, included the following : alopecia .and scabbing, sparse haircoat,
and malligned upper incisors with associated ocular discharge.
The following gross changes were noted during necropsy in the treated and control groups: hydronephrosis with or without distended ureters, misshapen kidney, distended uterus and cervix, and adherence of the liver to the kidney.
The test article had a marked inhibitory effect on maternal body weight gain at 250 and 500 mg/kg/day during the overall treatment interval.Moreover, marked reductions in gain were evident at 500 mg/kg/day during the overall gestation interval. Weight loss was observed during the gestation day 6 to 9 subinterval for both groups. All of these decreases were statistically significant. No similar effect was observed at 50 mg/kg/day.
An increase in postimplantation loss was noted for the 250 and 500 mg/kg/day groups, relative to the control. The increase was statistically significant at 500 mg/kg/day. The test article had no effect on the i.e., corpora lutea, total implantations, viable litter size, and sex Distribution, at 500 mg/kg/day and less.

Dose descriptor:

NOAEL

Effect level:

50 mg/kg bw/day (actual dose received)

Basis for effect level:

other: maternal toxicity

Dose descriptor:

NOAEL

Effect level:

50 mg/kg bw/day (actual dose received)

Basis for effect level:

other: developmental toxicity

Details on embryotoxic / teratogenic effects:

Embryotoxic / teratogenic effects:yes

Details on embryotoxic / teratogenic effects:
A treatment-related trend of fetal body weight inhibition was observed at all dosage levels. Fetal body weights were statistically significantly less than the control at 250 and 500 mg/kg/day. Weight inhibition, although very slight and not statistically significant, was also observed at 50 mg/kg/day and was deemed compound related as it was considered part of the trend observed at higher dosage levels.
The incidence of fetal malformations occurring in the treated groups was not meaningfully different from the control. A single instance each of a tail anomaly with anal atresia, and a vertebral anomaly occurred in a 250 mg/kg/day litter. Also, one 500 mg/kg/day fetus exhibited a retroesophageal aortic arch. No malformations occurred in the control and 50 mg/kg/day animals.
With respect to developmental variations, the number of litters exhibiting unossification of sternebrae #5 and/or #6 was increased exclusively at 500 mg/kg/day relative to the control. The remaining variations were noted in the control and treated groups at similar incidence or occurred as an isolated incidence and were deemed biologically irrelevant.

Abnormalities:

not specified

Developmental effects observed:

not specified

Conclusions:

Based on these results, o/p-TSA did not produce a teratogenic effect when administered orally to mated Charles River COBS CD rats at 500 mg/kg/day and less.

Executive summary:

A study was performed under GLP and according to a method similar to currently internationally accepted guidelines. Performed in accordance with Series 83-3 of the Environmental Protection Agency Pesticide Assessment Guidelines, Subdivision F, Hazard Evaluation: Human and Domestic Animals, issued November, 1982. Mated Charles River COBS CD rats consecutively assigned to one control and three treatment groups of 25 animals each were used to determine the teratogenic potential of Santicizer 9. Dosage levels of 50, 250 and 500 mg/kg/day were administered orally by gavage as a single daily dose on days 6 through 15 of gestation at a constant volume of 10 ml/kg. The control group received the vehicle only, corn oil, on a comparable regimen. Cesarean sections were performed on all surviving females on gestation day 20 and the fetuses were removed for teratologic evaluation.

Survival was 100% among all groups on study. Santicizer 9 produced meaningful changes in maternal body weight gain and several Cesarean section parameters when administered at 250 and 500 mg/kg/day. Maternal weight loss was evident during a portion of the treatment interval at 250 and 500 mg/kg/day and both groups exhibited significant (p<0.01) reductions in weight gain during the overall treatment period. Statistically significant reductions were also noted at 500 mg/kg/day during the overall gestation period. Fetotoxicity was apparent at 250 and 500 mg/kg/day as evidenced by increased postimplantation loss which was statistically significant at 500 mg/kg/day. In addition, a treatment-related trend of fetal body weight inhibition was noted at all dosage levels and values were significantly different from the control, p<0.01 at 250 and 500 mg/kg/day. An increase in the number of litters exhibiting unossification of sternebrae #5 and/or #6 was noted exclusively at 500 mg/kg/day and was correlated with fetal body weight reduction. Maternal appearance and behavior and the incidence of fetal malformations were not affected at any dosage level. Based on these results, Santicizer 9 did not produce a teratogenic effect when administered orally to mated Charles River COBS CD rats at 500 mg/kg/day and less.

Effect on developmental toxicity: via oral route

Endpoint conclusion:

adverse effect observed

Dose descriptor:

NOAEL

50 mg/kg bw/day

Study duration:

subacute

Species:

rat

Quality of whole database:

Reliable study, consistent with other available information.

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

There is one GLP compliant study on o/p-TSA available that is comparable to an OECD 414 study available in rats.

 

o/p-TSA was administered orally by gavage to groups of 25 mated rats per dose level of 0 (vehicle only, corn oil), 50, 250 and 500 mg/kg/day on days 6 through 15 of gestation. Cesarean sections were performed on all surviving females on gestation day 20 and the foetuses were removed for teratologic evaluation.

Survival was 100% among all groups on study. At 250 and 500 mg effects were observed in maternal body weight gain and several Cesarean section parameters. Statistically significant reductions were also noted at 500 mg/kg/day during the overall gestation period. Foetotoxicity was apparent at 250 and 500 mg/kg/day as evidenced by increased postimplantation loss which was statistically significant at 500 mg/kg/day. In addition, a treatment-related trend of foetal body weight inhibition was noted at all dosage levels and values were significantly different from the control, p<0.01 at 250 and 500 mg/kg/day. An increase in the number of litters exhibiting delayed ossification was noted exclusively at 500 mg/kg/day and was correlated with foetal body weight reduction. Maternal appearance and behaviour and the incidence of foetal malformations were not affected at any dosage level. Based on these results, o/p-TSA did not produce a teratogenic effect when administered orally to mated rats at 500 mg/kg/day and less. A NOAEL of 50 mg/kg bw/d was established for maternal and developmental toxicity.  

Results are well comparable to results on p-TSA from an OECD 414 study in rabbits by dietary route that resulted to a NOAEL for both maternal en foetal toxicity of p-TSA of 3000 ppm (114 mg/kg bw/day)

Justification for selection of Effect on developmental toxicity: via oral route:
Only available high quality study evaluating developmental toxicity

Justification for classification or non-classification

Toxicity to reproduction has been sufficiently evaluated in studies addressing both fertility and foetal development. Available studies for the evaluation of o/p-TSA for these endpoints indicated no concerns with respect to hazards related to reproduction, and thus no classification is required.