Registration Dossier

Administrative data

Description of key information

Under the conditions of a Combined Repeated Dose Toxicity Study with the Reproduction/Developmental Toxicity Screening Test, the oral administration by gavage of the test item to Wistar rats revealed adverse findings in parental animals and progeny at 600 and 2000/1000 mg/kg bw/d. Thus, the no observed adverse effect level (NOAEL) for general systemic toxicity was 200 mg/kg bw/d in both sexes of parental animals.

Key value for chemical safety assessment

Repeated dose toxicity: via oral route - systemic effects

Endpoint conclusion
Endpoint conclusion:
adverse effect observed
Dose descriptor:
NOAEL
200 mg/kg bw/day
Study duration:
subacute
Species:
rat
Quality of whole database:
GLP and guideline study.
System:
cardiovascular
Organ:
heart
other: myocardial necrosis

Repeated dose toxicity: inhalation - systemic effects

Endpoint conclusion
Endpoint conclusion:
no study available

Repeated dose toxicity: inhalation - local effects

Endpoint conclusion
Endpoint conclusion:
no study available

Repeated dose toxicity: dermal - systemic effects

Endpoint conclusion
Endpoint conclusion:
no study available

Repeated dose toxicity: dermal - local effects

Endpoint conclusion
Endpoint conclusion:
no study available

Mode of Action Analysis / Human Relevance Framework

Additional information

OECD 422

The test item was administered daily by gavage as a suspension to groups of 10 male and 10 female Wistar rats (F0 animals) at doses of 0, 200, 600 and 2000/1000 mg/kg body weight/day (mg/kg bw/d). The dose of the test group 3 was reduced from 2000 mg/kg bw/d to 1000 mg/kg bw/d after observing severe clinical findings in females at days around delivery. Control animals were dosed daily with the vehicle only (ultrapure water). The duration of treatment covered a 2-week premating period and mating period in both sexes, (mating pairs were from the same dose group), seven days post-mating in males, and the 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. After 2 weeks of premating treatment the F0 animals were mated to produce 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 once weekly during premating. In dams, food consumption was determined for gestation days (GD) 0-7, 7-14, 14-20 and postnatal days (PND) 1-4, 4-7, 7-10 and 10-13. Body weights of F0 parents were determined once a week, in males throughout the study and in females during premating. During gestation and lactation period, F0 females were weighed on GD 0, 7, 14 and 20, on the day of parturition (PND 0) and on PND 4, 7, 10 and 13. Estrous cycle data were evaluated for F0 generation females over a two-week period prior to mating until evidence of mating occurred. Moreover, the estrous stage of each female was determined on the day of scheduled sacrifice. The pups were sexed and examined for macroscopically evident changes on PND 0. They were weighed on PND 1, 4, 7 and 13. Their viability was recorded. At necropsy on PND 4 and 13, all pups were sacrificed with CO2, under isoflurane anesthesia, and examined macroscopically for external and visceral findings. Anogenital distance (defined as the distance from the anus [center of the anal opening] to the base of the genital tubercle) measurements were conducted in a blind randomized fashion, using a measuring ocular on all live male and female pups on PND 1. All surviving male pups were examined for the presence or absence of nipple/areola anlagen on PND 13. The number of nipple/areola anlagen were counted. Clinico-chemical and hematological examinations were performed in 5 animals per sex and group towards the end of the administration period. Blood samples from all dams at PND 14 and all males at termination were taken by puncturing the retrobulbar venous plexus under isoflurane anesthesia for hormone measurement. Blood samples were taken from all surplus pups at PND 4 as well as one male and one female pup per litter at PND 13 by decapitation under isoflurane anesthesia for hormone measurement. At the end of the administration period a functional observational battery was performed and motor activity was measured in 5 parental males and females per group. 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 in ultrapure water at room temperature over a period of 7 days,
• the correctness of the prepared concentrations

The following test substance-related adverse effects/findings were noted:

Test group 3: 2000/1000 mg/kg bw/d

F0 PARENTAL ANIMALS

Clinical examinations

Gestation:

• In total 4 females with adverse findings

• 4 females with semiclosed eyelid

• 3 females with tremors

• 2 females in general poor conditions

• 1 female with hypothermia

• 1 female in reduced nutritional condition

• 3 females found dead

Lactation

• In total 2 females with adverse findings

• 1 female in reduced nutritional condition

• 1 female in general poor conditions

• 1 female with pale skin

• 1 female with tremors

• 1 female found dead

• Decreased food consumption (d1-13: -25%)

• Decreased body weight gain (-62%)

Reproductive performance

• Decreased gestation index (50%)

• Decreased live birth index (58.3%)

• Increased postimplantation loss (36.1%)

• Increased number of still born pups (41.7%)

• Increased number of litters with stillborn pups (42.9%)

• Increased number of litters with all stillborn pups (28.6%)

• 1 female with insufficient maternal care and pups not properly nursed

Clinical pathology

• no test substance-related adverse findings

 

Pathology

• Death of four females

• Minimal to severe myocardial necrosis in the heart of six females

• Moderate to severe degeneration of the adrenal cortex of three females

• Macroscopically observed foci in the glandular stomach of four males

• Erosions/ulcer, sero-cellular crusts, inflammatory cell infiltrates, edema,

glandular atrophy, hyperemia in males and/or females

• Minimal to slight increase in basophilic tubules in nine males

F1 PUPS

Clinical examinations/ gross findings

• no test substance-related adverse findings

Test group 2: 600 mg/kg bw/d

F0 PARENTAL ANIMALS

Clinical examinations

Gestation

• In total 2 females with adverse signs

• 2 females in general poor conditions

• 1 female with hypothermia

• 1 female sacrificed moribund

Lactation:

• 1 female in general poor conditions

 

Reproductive performance

• Decreased gestation index (80%)

• Decreased live birth index (86.5%)

• Increased number of still born pups (13.5%)

• Increased number of litters with stillborn pups (44.4%)

• Increased number of litters with all stillborn pups (11.1%)

• 1 female with insufficient maternal care

• 1 female nursed pups not properly

Clinical pathology

• No test substance-related adverse findings

 

Pathology

• Moribund state of one female

• Minimal to moderate myocardial necrosis in the heart of three females

• Severe degeneration of the adrenal cortex of one female

F1 PUPS

Clinical Examinations/ Gross Findings

• No test substance-related adverse findings

Test group 1: 200 mg/kg bw/d

F0 PARENTAL ANIMALS

Clinical examinations, Reproductive Performance, Clinical Pathology, Pathology

• No test substance-related adverse findings

F1 PUPS

Clinical Examinations/ Gross Findings

• No test substance-related adverse findings

Conclusion

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 item to Wistar rats revealed adverse findings in parental animals and progeny at 600 and 2000/1000 mg/kg bw/d. Thus, the no observed adverse effect level (NOAEL) for general systemic toxicity was 200 mg/kg bw/d in both sexes of parental animals.

Justification for classification or non-classification

Classification, Labelling, 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. Myocardial necrosis in female animals of test group 2 and 3 leading to death were observed. As a result the substance is considered to be classified as STOT RE 2 under Regulation (EC) No 1272/2008, as amended for the tenth time in Regulation (EU) No 2017/776.