4,4'-azobis[4-cyanovaleric] acid

Endpoint summary

Key value for chemical safety assessment

Effects on fertility

Description of key information

The NOAEL for reproductive performance and fertility was 1000 mg/kg bw/d for male and female Wistar rats. The NOAEL for developmental toxicity was 1000 mg/kg bw/d. 

Effect on fertility: via oral route

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

NOAEL

1 000 mg/kg bw/day

Study duration:

subacute

Species:

rat

Quality of whole database:

The study was conducted according to guideline and GLP.

Effect on fertility: via inhalation route

Endpoint conclusion:

no study available

Effect on fertility: via dermal route

Endpoint conclusion:

no study available

Additional information

An oral repeated dose toxicity study was conducted according to OECD 422 in rats. The test substance was administered by gavage to groups of 10 male and 10 female Wistar rats (F0 generation) at effective dose levels of 0 mg/kg body weight/day (mg/kg bw/d; test group 0), 100 mg/kg bw/d (test group 1), 300 mg/kg bw/d (test group 2) and 1000 mg/kg bw/d (test group 3). Drinking water containing 0.5% sodium carboxymethyl cellulose served as vehicle. Considering a purity of the test substance of 81.5%, the dose levels of the product, were chosen to be 125, 400 and 1250 mg/kg bw/d, respectively, to achieve an intake of 100, 300 and 1000 mg/kg bw/d. The duration of treatment covered a 2-week premating period and mating in both sexes (mating pairs were from the same dose group) as well as entire gestation and lactation period in females up to one day prior to the day of schedule sacrifice of the animals.

The parents' and the pups' state of health was checked each day, and parental animals were examined for their mating and reproductive performances. F0 animals were mated for a maximum of two weeks after the beginning of treatment to produce a litter (F1 generation pups). As soon as sperm was detected in the vaginal smear, mating was discontinued. F0 animals were examined for their reproductive performance including determinations of the number of implantations and the calculation of the postimplantation loss in all F0 females. A detailed clinical observation (DCO) was performed in all animals before initial test substance administration and, as a rule, thereafter at weekly intervals.

Food consumption of the F0 parents was determined regularly once weekly before and after the mating period, as well as in dams during gestation days 7,14 and 20 and lactation days 4, 7, 10 and 13. In general, the body weights of F0 animals were determined once a week. However, during gestation and lactation, F0 females were weighed on gestation days (GD) 0, 7, 14 and 20, and on postnatal days (PND) 0, 4, 7, 10 and 13. The pups were sexed and examined for macroscopically evident changes on PND 0. They were weighed on PNDs 1, 4, 7 and on PND 13 and their viability was recorded. On day 1 after birth the anogenital distance (AGD) was determined on all live male, female and uncertain pups. On PND 4, the individual litters were standardized in such a way that, whenever possible, each litter contains 4 male and 4 female pups (as a rule, the first 4 surviving pups/sex in each litter were taken for further rearing). On PND 13, all male F1 pups were examined for retention of nipples/areolae. The number of nipples/areolae anlagen were counted. At necropsy on PNDs 4 and 13, all pups were sacrificed with CO2 under isoflurane anesthesia and examined macroscopically for external and visceral findings. Blood samples were taken from all surplus pups or 2 preferably female pups per litterat PND 4 as well as one male and one female pup per litter at PND 13 by decapitation under isoflurane anesthesia. Additionally, blood samples from all dams at PND 14 and all males at termination were taken by puncturing the retrobulbar venous plexus under isoflurane anesthesia. Thyroid glands/parathyroid glands were fixed in neutral buffered 4% formaldehyde solution and transferred to the Pathology Laboratory for possible further processing. Towards the end of the administration period a functional observational battery was performed and motor activity was measured in 5 parental animals per sex and test group. Clinicochemical and hematological examinations were performed in 5 parental animals per sex and group towards the end of the administration period. All F0 parental animals were sacrificed by decapitation under isoflurane anesthesia and were assessed by gross pathology. Weights of selected organs were recorded and a histopathological examination was performed.

The various analyses confirmed the stability of the test-substance preparations for a period of 7 days at room temperature, the homogeneous distribution of the test substance in the vehicle and the correctness of the prepared concentrations.No treatment-related, adverse effects were observed in pups and parent animals of any dose groupe (100, 300 and 1000 mg/kg bw).

Under the conditions of this Combined Repeated Dose Toxicity Study with the Reproduction/Developmental Toxicity Screening Test, the oral administration by gavage of the test substance to Wistar rats revealed no signs of systemic toxicity up to a dose level of 1000 mg/kg bw/d in animals of both sexes. Thus, the NOAEL for general systemic toxicity was 1000 mg/kg bw/d for male and female Wistar rats. The NOAEL for reproductive performance and fertility was also set to 1000 mg/kg bw/d formale and female Wistar rats. The NOAEL for developmental toxicity was 1000 mg/kg bw/d. 

Justification for classification or non-classification

Classification, Labeling, and Packaging Regulation (EC) No 1272/2008

The available experimental test data are reliable and suitable for classification purposes under Regulation (EC) No 1272/2008. The NOAEL for reproductive performance and fertility was 1000 mg/kg bw/d and the NOAEL for developmental toxicity was 1000 mg/kg bw/d. As a result the substance is not considered to be classified for toxicity to reproduction under Regulation (EC) No 1272/2008, as amended for the tenth time in Regulation (EC) No 2017/776.