N,N-dimethylaniline

Endpoint summary

Key value for chemical safety assessment

Effects on fertility

Link to relevant study records

Reference

Endpoint:

one-generation reproductive toxicity

Remarks:

based on test type (migrated information)

Type of information:

experimental study

Adequacy of study:

weight of evidence

Reliability:

4 (not assignable)

Qualifier:

according to guideline

Guideline:

other: Maternal and developmental effect of N,N-dimethylaniline in CD-1 albino mice were assessed in a 1-generation study.

GLP compliance:

not specified

Species:

mouse

Strain:

CD-1

Sex:

female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River Breeding Laboratories, Inc.
- Age: No data available
- Weight at study initiation: 21.0 to 30.0 g
Fasting period before study: N/A
- Housing: The mice were housed individually in suspended •polycarbonate cages with San-i-cel bedding in a controlled environment.
- Diet (e.g. ad libitum): Purina Certified
Rodent Chow® #5002, ad libitum
- Water (e.g. ad libitum): Ad libitum
- Acclimatization period: 5 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22±3°C
- Humidity (%): No data available
- Air changes (per hr): 10-15 times per hour
- Photoperiod (hrs dark / hrs light): 12-hr dark/12-hr light

Route of administration:

oral: gavage

Vehicle:

corn oil

Details on exposure:

PREPARATION OF DOSING SOLUTIONS:

DIET PREPARATION
- Rate of preparation of diet (frequency): N/A
- Mixing appropriate amounts with (Type of food): N/A
- Storage temperature of food: N/A

VEHICLE
- Justification for use and choice of vehicle (if other than water): Corn oil
- Concentration in vehicle: 365 mg/kg/day
- Amount of vehicle (if gavage): 5.0 mg/kg of body weight
- Lot/batch no. (if required): No data available
- Purity: No data available

Details on mating procedure:

- M/F ratio per cage: N/A (timed-pregnant female from supplier)
- Length of cohabitation: No data available
- Proof of pregnancy: [vaginal plug / sperm in vaginal smear] referred to as [day 0 / day 1] of pregnancy No data available
- After ... days of unsuccessful pairing replacement of first male by another male with proven fertility. No data available
- Further matings after two unsuccessful attempts: [no / yes (explain)] No data available
- After successful mating each pregnant female was caged (how): No data available
- Any other deviations from standard protocol: No data available

Duration of treatment / exposure:

8 days

Frequency of treatment:

Once daily on gestation day 7 through gestation day 14.

Details on study schedule:

- F1 parental animals not mated until [...] weeks after selected from the F1 litters.: No data available
- Selection of parents from F1 generation when pups were [...] days of age.: No data available
- Age at mating of the mated animals in the study: [...] weeks: No data available

Remarks:

Doses / Concentrations:
365 mg/kg-bw/day
Basis:
actual ingested

No. of animals per sex per dose:

Control: 50 females
365 mg/kg/day: 50 females

Control animals:

yes, concurrent vehicle

Details on study design:

Constant dosing volume of 5.0 ml/kg of body weight based on the weights measured on Day 7 of gestation of mice.

Parental animals: Observations and examinations:

All animal s were observed -twice daily during the study (morning and afternoon) for clinical signs of toxicity and mortality. Body weights for the dams were also recorded on gestation day 2, 7 and 18 plus on day 4 of postpartum.

Oestrous cyclicity (parental animals):

No data available

Sperm parameters (parental animals):

Parameters examined in [all/P/F1/F2] male parental generations:No data available

Litter observations:

Pup counts and litter weights were recorded within 12 hours of birth and on Day 3 postpartum. Litter weight and mean pup weight changes (Day 3-Birth) were also calculated, and the viability of offspring from birth to Day 3 was assessed.

Postmortem examinations (parental animals):

Necropsy examinations were performed only on females which did not deliver. The nongravid uteri were treated with a. 10% sodium sulfide solution to determine the prior existence of a pregnant state.

Postmortem examinations (offspring):

No data available

Statistics:

Means and standard deviations were calculated for the following parameters: maternal body weights for each interval collected, litter weights, mean pup weights, and pup counts (live and dead) for each interval collected, weight changes for dams (Day 18-Day 7 of gestation) and litters (Day 3-Birth), and offspring viability ratios from birth to Day 3 postpartum. Treatment group means were compared to the common control group by Student's t-test.

Reproductive indices:

Number of live/dead litters was observed.

Offspring viability indices:

Number of live/dead litters was observed.

Clinical signs:

effects observed, treatment-related

Dermal irritation (if dermal study):

not specified

Mortality:

not specified

Body weight and weight changes:

no effects observed

Description (incidence and severity):

No differences in mean maternal body weight or mean weight change were observed.

Food consumption and compound intake (if feeding study):

no effects observed

Description (incidence and severity):

No differences in mean maternal body weight or mean weight change were observed.

Food efficiency:

not specified

Water consumption and compound intake (if drinking water study):

not specified

Ophthalmological findings:

not specified

Haematological findings:

not specified

Clinical biochemistry findings:

not specified

Urinalysis findings:

not specified

Behaviour (functional findings):

not specified

Immunological findings:

not specified

Organ weight findings including organ / body weight ratios:

not specified

Histopathological findings: non-neoplastic:

not specified

Other effects:

not specified

Reproductive function: oestrous cycle:

not specified

Reproductive function: sperm measures:

not specified

Reproductive performance:

no effects observed

Clinical signs:
Deaths occurred in two mice from the test material and an additional N,N-dimethylaniline-treated animal was sacrificed in extremis on Day 18 of gestation (Study Day 12); this animal was noted to be lethargic, prostrate, cold to the touch and had mucoid secretion from the vagina prior to sacrifice. Prostration, tremors, ataxia, lethargy, piloerection, vaginal secretion, and/or anal bleeding were observed in an occasional test material -treated animal prior to death.

Reproductive performance:
No apparent adverse effects on reproductive outcome and time to delivery. Litters were born on days 18 through 23 of gestation.

Vehicle Control N,N-Dimethylaniline
(365 mg/kg/day)
Number Treated 50 50
Number of Deaths 0 3
Number of Survivors:
No pregnant 9 7
Pregnant 41 37
Fertilized without Subsequent
Implantation 0 3
Number of Litters:
Live litters 41 36
Dead Litters 0 1
Resorbed Litters 0 0
Deli very Index:
Ratio 41/41 36/37
Percent 100 97

Other observation: The percentage of litters cannibalized in test material was 4% (5/36).

Dose descriptor:

LOAEL

Effect level:

365 mg/kg bw/day

Based on:

test mat.

Remarks:

Body weight

Sex:

female

Basis for effect level:

body weight and weight gain

Remarks on result:

other: not specified

Clinical signs:

not specified

Dermal irritation (if dermal study):

not specified

Mortality:

not specified

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 specified

Clinical biochemistry findings:

not specified

Urinalysis findings:

not specified

Behaviour (functional findings):

not specified

Immunological findings:

not specified

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 specified

Other effects:

not specified

Reproductive function: oestrous cycle:

not specified

Reproductive function: sperm measures:

not specified

Reproductive performance:

not specified

Dose descriptor:

other: not specified

Based on:

not specified

Sex:

not specified

Basis for effect level:

other: not specified

Remarks on result:

other: not specified

Clinical signs:

not specified

Mortality / viability:

not specified

Body weight and weight changes:

no effects observed

Description (incidence and severity):

Statistical evaluation of mean litter and per-pup average weights revealed no noteworthy variations.

Sexual maturation:

not specified

Organ weight findings including organ / body weight ratios:

not specified

Gross pathological findings:

not specified

Histopathological findings:

not specified

Reproductive performance:
Offspring viability ratio was significantly lower than the control group; however, this difference was slight and is considered to be incidental.

Dose descriptor:

LOAEL

Generation:

F1

Effect level:

365 mg/kg bw/day

Based on:

test mat.

Remarks:

Body weight

Sex:

male/female

Basis for effect level:

body weight and weight gain

Remarks on result:

other: not specified

Reproductive effects observed:

not specified

Conclusions:

LOAEL for the parental generation and the F1 generation were considered to be 365 mg/kg/day when N,N-dimethylaniline was administered orally.

Executive summary:

In a 1-generation study, N,N-dimethylaniline was assessed for its potential to cause adverse reproductive effects in timed-pregnant female CD-1 albino mice. The test material was administered orally by gavage on a daily basis on gestation day 7 through gestation day 14 with corn oil as vehicle. For test material, means and standard deviations were calculated by using two factors related mortality and body weight. No differences in mean maternal body weight or mean weight change observed in parents. Since N,N-dimethylaniline had no adverse effects on reproductive potential, survival or weight gain of the dams, or the fact that evaluation of mean litter and per-pup average weights revealed no noteworthy variations but with an indication of lowered offspring viability ratio, LOEAL was considered to be 365 mg/kg/day.

Effect on fertility: via oral route

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

LOAEL

365 mg/kg bw/day

Study duration:

subacute

Species:

mouse

Quality of whole database:

K2 level data is referred from reliable source of journal

Effect on fertility: via inhalation route

Endpoint conclusion:

no study available

Effect on fertility: via dermal route

Endpoint conclusion:

no study available

Additional information

WoE Summary of 121-69-7 for toxicity to reproduction

Based on the various studies available with Klimish rating 2 for the target as well as read across substances for CAS: 121-69-7 based on the USEPA’s HPV category approach ofsubstances that are part of a group of compounds known as Monocyclic Aromatic Amines Category. Also category is based on organic functional group along with similar mechanistic approach and having structural similarities defined by QSAR toolbox. The results for target as well as analogues are summarized as follows

Sr. No	End point	Value	Species	Effects	Remarks
1	LOAEL	274.66 mg/Kg bw /d	Rat	Effects observed on kidney enlargement (histopath: basophilic cortical tubular changes). Liver enlargement (histopath equivocal)	Predicted data
2	LOAEL	365 mg/Kg bw /d	Mouse	Effects observed in clinical signs, and reproductive performance	Data from Publication for CAS: 121-69-7
3	NOAEL (F1)   LOAEL (P)	10 mg/kg bw/d   10 mg/kg bw/d	Rat	No adverse effects on presence of methemoglobinemia, increased relative spleen weight, decreased red blood cell (RBC) count, and haematological changes indicative of increased Hematopoietic activity.   Effect observed on Maternal toxicity and Absolute weight gain, spleen liver weight, increased methemoglobinemia and decreased red blood cell count.	Data from Publication for CAS: 142-04-1

 

Based on the studies summarized in the above table it can be observed that NOAEL values for F1 genertion is from 10 mg/Kg bw/d as well as LOAEL value varies from 10-365 mg/kg bw/d based on the data from prediction as well as publication for target & read across substance. The effect observed on the above doses are

·        Effects observed on kidney enlargement (histopath: basophilic cortical tubular changes). Liver enlargement (histopath equivocal)

·        Effects observed in clinical signs, and reproductive performance

·        Effect observed on Maternal toxicity and Absolute weight gain, spleen liver weight, increased methemoglobinemia and decreased red blood cell count.

 

Thus based on above discussion it can be concluded that substance CAS: 121-69-7 is expected to show the similar toxicological effect based on the effects observed on the other category members. Since the no effective dose value (NOAEL) is higher than 10 mg/Kg bw/d and LOAEL value is more than 10 mg/kg bw/d for one of read across as well as 365 mg/kg bw/d for target substance. Thus based on this value it can be concluded that substance CAS: 121-69-7 is considered to be not toxic to reproduction at the above mentioned dose. Also there are no known evidence of adverse effect on reproduction to Human of CAS: 121-69-7 as well as estrogen receptor binding affinity does not indicates any mechanistic trigger based on absence of noncyclic structure that would raise concern of CAS: 121-69-7 on toxicity to human reproduction.

Justification for selection of Effect on fertility via oral route:

LOAEL for the parental generation and the F1 generation were considered to be 365 mg/kg/day when N,N-dimethylaniline was administered orally.

Effects on developmental toxicity

Link to relevant study records

Reference

Endpoint:

developmental toxicity

Type of information:

experimental study

Adequacy of study:

weight of evidence

Reliability:

4 (not assignable)

Principles of method if other than guideline:

This study, conducted for the Monsanto Company. was designed to evaluate the embryotoxic. fetotoxic and/or teratogenic potential of diethyl alanine in the rat.

GLP compliance:

not specified

Limit test:

no

Species:

rat

Strain:

CD-1

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source:Charles River Breeding Laboratories. Inc. Shaver Road Portage. Michigan 49081
- Age at study initiation: Six weeks
- Weight at study initiation: 207 gms
- Fasting period before study:
- Housing: Individually, except during the first week of the acclimation period (two females/cage) and mating, in stainless steel suspended cages with wire mesh floors.
- Diet (e.g. ad libitum): Purina. Certified Rodent Chow No. 5002 (mash) fed ad libitum.
- Water (e.g. ad libitum): Tap water
- Acclimation period: 21 days

ENVIRONMENTAL CONDITIONS
- Temperature (°F): 65-74 deg F
- Humidity (%): Pretest - 33-66%
Study - 26-68%.
- Photoperiod (hrs dark / hrs light): 12 hour light/dark cycle (7 AM to 7 PM) via automatic timer.

Route of administration:

oral: gavage

Vehicle:

corn oil

Details on mating procedure:

- M/F ratio per cage: 1:1
- Length of cohabitation: overnight
- Proof of pregnancy: [vaginal plug / sperm in vaginal smear] referred to as [day 0 / day 1] of pregnancy : Vaginal smears were taken early in the morning following intervals of cohabitation and females were considered to have mated if sperm and/or a vaginal plug was observed(Day 0 of gestation).
- After successful mating each pregnant female was caged (how):Individually, except during the first week of the acclimatization period (two females per cage) and mating, in stainless steel suspended cages with wire mesh floors.

Frequency of treatment:

daily

Duration of test:

Days 6-15 of gestation

Remarks:

Doses / Concentrations:
0, 50, 250 and 500 mg/kg/day
Basis:
nominal in diet

No. of animals per sex per dose:

Control: 24 pregnant females
50 mg/kg/day: 24 pregnant females
250 mg/kg/day: 24 pregnant females
500 mg/kg/day: 29 pregnant females

Control animals:

yes, concurrent vehicle

Maternal examinations:

Body weights Recorded on Days 0, 6, 10, 12, 15 and 20 of gestation.

Ovaries and uterine content:

The ovaries were dissected free from the uterus and evaluated for the presence and number of corpora lutea. When no uterine implants were grossly apparent, the uterus was stained with ammonium sulphides and the number of foci was counted.

Fetal examinations:

All fetuses were given a gross examination for malformations/variations of the external form. Subsequently, each fetus was weighed and sexed (ano-genital distance) which was confirmed by internal inspection of the gonads at subsequent evaluation.

Statistics:

Due to the small group sizes involved, data were not evaluated statistically.

Indices:

No data

Historical control data:

No data

Details on maternal toxic effects:

Maternal toxic effects:yes

Details on maternal toxic effects:
Symptoms in dams included decreased body weight gain and food consumption, as well as excessive salivation and staining of the fur in the ano-genital region. Gross necropsy revealed discolored lungs in some dams at all dose levels.

Dose descriptor:

LOAEL

Effect level:

50 mg/kg bw/day

Based on:

test mat.

Basis for effect level:

other: maternal toxicity

Details on embryotoxic / teratogenic effects:

Embryotoxic / teratogenic effects:no effects. Remark: Treatment with the highest dose level of diethylaniline was observed to be fetotoxic (reduced fetal weight gain), however, it was not considered to be embryotoxic or teratogenic.

Dose descriptor:

LOAEL

Effect level:

500 mg/kg bw/day

Based on:

test mat.

Basis for effect level:

other: teratogenicity

Abnormalities:

not specified

Developmental effects observed:

not specified

Conclusions:

The lowest observed adverse effect level (LOAEL) for the parental generation is considered to be 50 mg/kg/day of diethylaniline given orally by gavag and the lowest observed adverse effect level (LOAEL) for the F1 generation is considered to be 500 mg/kg/day of diethylaniline.

Executive summary:

In a 1-generation study, the embryotoxic, fetotoxic and/or teratogenic effect of diethylaniline was evaluated in female CD rats treated with 0, 50, 250 or 500 mg/kg/day of diethylaniline during Day 6-15 of gestation. No mortality occurred in the control, low- or mid-dose groups, but some maternal toxicity was evident at each dose level. Low-dosed females experienced depressed weight gain during the treatment period and their mean food consumption was statistically lower than control. Manifestations of maternal toxicity were also seen at the mid- and high-dose levels; however, these effects were more extreme. Physical examination of females in the mid- and high-dose groups revealed an increased incidence of females with excessive salivation, staining of the skin/fur in the ano-genital area and excessive lacrimation. No adverse effect of treatment was evident from uterine implantation data. Mean fetal weight and fetal sex distribution were unaffected by treatment at the low or mid-dose levels. Thus, LOAEL for the dams is considered to be 50 mg/kg/day and for the offspring 500 mg/kg/day when pregnant female CD rats are given diethylaniline orally.

Effect on developmental toxicity: via oral route

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

LOAEL

50 mg/kg bw/day

Study duration:

subacute

Species:

rat

Quality of whole database:

K2 level data obtained from relaible source

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

WoE Summary of 121-69-7 for developmental toxicity

Based on the various studies available with Klimish rating 2 for the target as well as read across substances for CAS: 121-69-7 based on the USEPA’s HPV category approach ofsubstances that are part of a group of compounds known as Monocyclic Aromatic Amines Category. Also category is based on organic functional group along with similar mechanistic approach and having structural similarities defined by QSAR toolbox. The results for target as well as analogues are summarized as follows

Sr. No	End point	Value	Species	Route	Effects	Remarks
1	LOAEL (developmental)   LOAEL (maternal toxicity)	365 mg/ kg bw/ d   365 mg/kg bw/d	Mouse	Oral	Effects observed in clinical signs, and reproductive performance	Data from Publication for 121-69-7
2	LOAEL (developmental)   LOAEL (maternal toxicity)	50 mg/Kg bw /d   500 mg/kg bw/d	Rat	Oral	Effects observed in weight gain, food consumption and uterine implantation.   Effects observed in Reduced fetal weight and retarded sternebral ossification.	Data from Publication for CAS: 91-66-7
3	LOEL	149 mg/kg bw/d	Rat	Oral	Fetal weight reduction	Predicted data

 

Based on the studies summarized in the above table with various routes it can be observed that LOAEL values varies from 50 - 500 mg/kg bw/d for oral route based on the data for target as well as read across substances. The no effects observed on the higher doses was listed as follows

o  Effects observed in clinical signs, and reproductive performance

o  Effects observed in weight gain, food consumption and uterine implantation.

o  Effects observed in Reduced fetal weight and retarded sternebral ossification.

o  Fetal weight reduction

Thus based on above discussion it can be concluded that substance CAS: 121-69-7 is expected to show the similar toxicological effect based on the effects observed on the other category members. Since the Low observed adverse effective dose value (LOAEL) is higher than 50 mg/Kg bw/d vial oral route. It can be concluded that substance CAS: 121-69-7 is considered to be not toxic to maternal toxicity as well as developmental effects via oral route for above mentioned doses. Also there are no known evidence of adverse effect on reproduction to Human of CAS: 121-69-7 as well as estrogen receptor binding affinity does not indicates any mechanistic trigger based on absence of noncyclic structure that would raise concern of CAS: 121-69-7 on developmental toxicity.

Justification for selection of Effect on developmental toxicity: via oral route:

The lowest observed adverse effect level (LOAEL) for the parental generation is considered to be 50 mg/kg/day of diethylaniline given orally by gavag and the  lowest observed adverse effect level (LOAEL) for the F1 generation is considered to be 500 mg/kg/day of diethylaniline.

Justification for classification or non-classification

Based on above details it can be concluded that substance N,N-dimethylaniline is considered to be not toxic to reproduction as well as developmetal effects