m-phenylenediamine

Endpoint summary

Key value for chemical safety assessment

Effects on developmental toxicity

Description of key information

Oral: NOAEL; OECD 414; GLP; developmental gavage; rat; developmental effects were observed at maternally toxic levels; reliability = 2.

NOT CLASSIFIED

Link to relevant study records

Reference

Endpoint:

developmental toxicity

Type of information:

experimental study

Adequacy of study:

supporting study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

comparable to guideline study with acceptable restrictions

Remarks:

Study does not state a specific OECD guideline and is not GLP compliant, but it does seem to follow OECD guideline 414 closely with a well documented methodology and results.

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 414 (Prenatal Developmental Toxicity Study)

GLP compliance:

not specified

Limit test:

no

Species:

rat

Strain:

other: Him: OFA (SD) SPF

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Forschungs-insitut fur Verscuchstierzucht (Research Institute for Test Animal Breeding), Himberg
- Age at study initiation: 6-10 months old
- Weight at study initiation: 200-250 g
- Housing: Kept individually in Type III Makrolon cages
- Diet (e.g. ad libitum): Ad litbitum with Altromin Breeding Diet 1314 ff, 10-mm pellets sterilized by gamma radiation, 2 Mrad
- Water- Autoclaved tap water ad libitum from drinking bottles

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 21± 2°C
- Humidity (%): 55± 5%
- Air changes (per hr): 15 times per hour with pure fresh air
- Photoperiod (hrs dark / hrs light): Exclusively artificial light (200 lux at a height of 2m) for 10 hours ( from 7 AM - 5 PM) without dawn.

Route of administration:

oral: gavage

Vehicle:

water

Details on exposure:

The test substance was dissolved or suspended fresh daily and administered perorally once daily in the morning from the 6th to the 15th test days inclusive, using a metal esophageal probe.

Analytical verification of doses or concentrations:

not specified

Details on analytical verification of doses or concentrations:

No data.

Details on mating procedure:

- Impregnation procedure: Co-housed
- If cohoused:
- M/F ratio per cage: No data
- Verification of same strain and source of both sexes: Yes
- Proof of pregnancy: Vaginal plug, referred to as gestational day (GD) 0 of pregnancy

Duration of treatment / exposure:

Daily from GD 6 to GD 15

Frequency of treatment:

Daily

No. of animals per sex per dose:

25 mated rats

Control animals:

yes, concurrent vehicle

other: Acetylsalicylic acid was given as a positive control

Details on study design:

- Dose selection rationale: Range-finding study
- Rationale for animal assignment (if not random): Based on a random number table

Maternal examinations:

CAGE SIDE OBSERVATIONS: Yes.
- Time schedule: Daily

DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule: weekly

BODY WEIGHT: Yes
- Time schedule for examinations: 0, 6, 15, and 20th day

FOOD CONSUMPTION AND COMPOUND INTAKE (if feeding study): Yes
- Food consumption for each animal determined and mean daily diet consumption calculated as g food/kg body weight/day: Yes

POST-MORTEM EXAMINATIONS: Yes
- Sacrifice on gestation day # 20
- Organs examined: ovaries and 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:

- Approximately one third of the judgable fetuses were collectively fixed for later evaluation of internal organs. The other two thirds were eviscerated and the organs were evaluated for completeness and possible malformations.
- Spinal column: The number of cervical, thoracic, lumbar and caudal vertebrae and the number of ossification centers.
- Sacrum was evaluated.
- Pelvic bones and ribs were evaluated and counted.
- Bones of extremities.
- Sternal ossification centers were determined.
- All cranial bones were investigated for the presence and degree of ossification.
- Number of ribs and sternal ossification centers were recorded.

Statistics:

Either the mean x together with the standard deviation s and sample size n or the absolute or percentage frequency is given. Data, with means and standard deviations, were compared by simple variance analysis and then a Scheffe test. With events for which there are absolute numbers and percentages or these can be calculated, first of all a kth 2-field chi2 test was applied using the related numbers that were also used for the calculation of the percentages. If significant differences were indicated, further checking was done with the four-field chi2 test. With small population numbers, Fischer's Exact Test was used. A significant limit of p = 0.05 was established for all tests.

Details on maternal toxic effects:

Maternal toxic effects:yes

Details on maternal toxic effects:
Six of the dams in the highest-dose group died before the 20th day.

Dose descriptor:

NOAEL

Effect level:

90 mg/kg bw/day

Basis for effect level:

other: developmental toxicity

Dose descriptor:

NOAEL

Effect level:

30 mg/kg bw/day

Basis for effect level:

other: maternal toxicity

Details on embryotoxic / teratogenic effects:

Embryotoxic / teratogenic effects:yes

Details on embryotoxic / teratogenic effects:
Statistically significant differences as compared to the negative control were found only in the highest-dose group. These differences manifested themselves as a reduction in the number of litters with live pups, lower average placenta weights, fewer total number of live pups, fewer live pups per litter, lower average body weight of a live pup, as well as an increase in the total resporptions, greater total number of late-dying embryos, greater total number of early dying embryos, higher percentage of dams with fetuses having minor alterations and greater frequency of fetuses having minor malformations. Major malformations were not found.
The postive control group showed the expected malformations in proportionate frequency and confirmed the sensitivity of the testing system.

Dose descriptor:

NOAEL

Effect level:

30 mg/kg bw/day

Basis for effect level:

other: fetotoxicity

Abnormalities:

not specified

Developmental effects observed:

no

Conclusions:

The test substance is strongly fetotoxic and might be weakly teratogenic, although only with doses high enough to be injurious to the dam.

Executive summary:

Rats were evaluated in a developmental toxicity study via oral doses of 10, 30, and 90 mg/kg bw/day. Maternal toxicity in the form of lethality occurred in the 90 mg/kg bw/day exposure group only. Reduction in the number of litters with live pups, lower average placenta weights, fewer total number of live pups, fewer live pups per litter, lower average body weight of a live pup, as well as an increase in the total resporptions, greater total number of late-dying embryos, greater total number of early dying embryos, higher percentage of dams with fetuses having minor alterations and greater frequency of fetuses having minor malformations occurred in the 90 mg/kg bw/dayexposure group. Thus, these effects occurred at maternally toxic concentrations. The test substance was not uniquely toxic to the developing fetus. The NOAEL for maternal systemic effects was 30 mg/kg bw/day. The NOAEL for fetal developmental effects was 30 mg/kg bw/day.

 

Effect on developmental toxicity: via oral route

Dose descriptor:

NOAEL

30 mg/kg bw/day

Additional information

Rats were evaluated in a developmental toxicity study via oral doses of 10, 30, and 90 mg/kg bw/day. Maternal toxicity in the form of lethality occurred in the 90 mg/kg bw/day exposure group only. Reduction in the number of litters with live pups, lower average placenta weights, fewer total number of live pups, fewer live pups per litter, lower average body weight of a live pup, as well as an increase in the total resorptions, greater total number of late-dying embryos, greater total number of early dying embryos, higher percentage of dams with fetuses having minor alterations and greater frequency of fetuses having minor malformations occurred in the 90 mg/kg bw/day exposure group. Thus, these effects occurred at maternally toxic concentrations. The test substance was not uniquely toxic to the developing fetus. The NOAEL for maternal systemic effects was 30 mg/kg bw/day. The NOAEL for fetal developmental effects was 30 mg/kg bw/day.

Justification for classification or non-classification

The substance was not tested in a reproductive toxicity study but was tested in a developmental toxicity study. The test substance was not uniquely toxic to the developing fetus. The substance cannot be classified for reproductive toxicity according to EU Classification, Labelling and Packaging of Substances and Mixtures (CLP) Regulation (EC) No. 1272/2008.