3-Isocyanatomethyl-3,5,5-trimethylcyclohexyl isocyanate, oligomers, 2-Hydroxy-1(2)- methylethyl carbamate blocked

Endpoint summary

Description of key information

OECD 422: NOAEL >= 1200 mg/kg bw/d

Key value for chemical safety assessment

Repeated dose toxicity: via oral route - systemic effects

Link to relevant study records

Reference

Endpoint:

short-term repeated dose toxicity: oral

Remarks:

combined repeated dose and reproduction / developmental screening

Type of information:

experimental study

Adequacy of study:

key study

Study period:

Apr-Jul 18

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 422 (Combined Repeated Dose Toxicity Study with the Reproduction / Developmental Toxicity Screening Test)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Limit test:

yes

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Expiration date of the lot/batch: 23-05-2019

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material: Room temperature
- Stability under test conditions: stable

FORM AS APPLIED IN THE TEST (if different from that of starting material)
- Test substance preparations in corn oil

Species:

rat

Strain:

Wistar

Details on species / strain selection:

Wistar Rat; Crl:WI(Han)

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River Laboraories, Research Models and Services, Germany GmbH
- Females (if applicable) nulliparous and non-pregnant: yes
- Age at study initiation: about 11-12 weeks (male animals), about 10 weeks (female animals)
- Housing: During pre-treatment: Polysulfonate cages Typ 2000P (H-Temp), floor area about 2065 cm2 (610 x 435 x 215 mm); supplied by TECHNIPLAST, Hohenpeißenberg, Germany
During pre-mating, mating, gestation, lactation, males after mating and females after weaning: Polycarbonate cages type III
- Diet (e.g. ad libitum): ad libitum
- Water (e.g. ad libitum): ad libitum

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 20-24°C
- Humidity (%):45-65%
- Air changes (per hr): 15
- Photoperiod (hrs dark / hrs light): 12h/12h

Route of administration:

oral: gavage

Vehicle:

corn oil

Details on oral exposure:

The test substance was applied as suspension.

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

The analytical verification of the test substance preparations were carried out as separate study at the test faciclity Competence Center Analytics of BASF SE. The study was carried out in compliance with GLP. The stability of the test substance in corn oil over a period of 7 days at room temperature was proven (Project No. 17L00369).

Duration of treatment / exposure:

The duration of treatment covered a 2-week premating period and mating period in both sexes, one day 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.

Frequency of treatment:

daily

Dose / conc.:

120 mg/kg bw (total dose)

Dose / conc.:

400 mg/kg bw (total dose)

Dose / conc.:

1 200 mg/kg bw (total dose)

No. of animals per sex per dose:

10

Control animals:

yes, concurrent vehicle

Details on study design:

- Dose selection rationale: The dose level selection was based on a 14-day range-finding study (10C0437/16C137).

Observations and examinations performed and frequency:

CAGE SIDE OBSERVATIONS: Yes
- Time schedule: conducted at least once daily for any signs of morbidity, pertinent behavioral changes and/or signs of overt toxicity. All animals were checked daily for any abnormal clinical signs before the administration as well as within 2 hours and within 5 hours after the administration.

DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule: Detailed clinical observations were performed in all animals prior to the administration period and thereafter at weekly intervals.

BODY WEIGHT: Yes
- Time schedule for examinations: Body weight of male and female parental animals was determined before the start of the administration period in order to randomize the animals. During the administration period body weight was determied on study day 0 and thereafter once a week at the same time of the day (in the morning).

FOOD CONSUMPTION AND COMPOUND INTAKE (if feeding study):
- food consumption was determined once a week for male and female parental animals.

FOOD EFFICIENCY:
- Body weight gain in kg/food consumption in kg per unit time X 100 calculated as time-weighted averages from the consumption and body weight gain data: No

OPHTHALMOSCOPIC EXAMINATION: Not specified

HAEMATOLOGY: Yes
- Time schedule for collection of blood: In the morning, blood was taken from the retro-bulbar vanous plexus from fasted animals.
- Anaesthetic used for blood collection: Yes (isoflurane)
- Animals fasted: Yes
- How many animals: 5 surviving parental males per group at termination and in 5 females with litters per group at PND 14.

CLINICAL CHEMISTRY: Yes
- Time schedule for collection of blood: In the morning, blood was taken from the retro-bulbar vanous plexus from fasted animals.
- Animals fasted: Yes
- How many animals: 5 surviving parental males per group at termination and in 5 females with litters per group at PND 14.

URINALYSIS: Not specified

IMMUNOLOGY: Not specified

OTHER:
- A functional observational battery was performed in the first five parental male animals per test group and the first surviving females with litter of all test groups at the end of the administration period. The FOB started with passive observations without disturbing the animals, followed by removal from the home cage, open field observations in a standard arena and sensorimotor tests as well as reflex tests.
- Motor activity (MA) was also measured from 14 pm onwards on the same day as the FOB was performed in the first five parental males and the first five surviving females with litter per group.
- For all females of the pool estrous cycle normality was evaluated before the beginning of the administration. In all parental females, in the premating phase, estrous cycle length and normality was evaluated by preparing vaginal smears during a minimum of 2 weeks prior to premating, mating and throughout cohabitytion until there is evidence of sperm in the vaginal smear. Additionally, on the day of scheduled sacrifice, the estrous status was also determined in all F0 female animals.
- Thyroid hormones: blood samples were taken from all surplus pups per litter at PND 4 as well as one male and one female pup per litter at PND14 by decapitation under isoflurane anesthesia. Additionally blodd samples from all dams at PND 14 and all males at termination were taken by puncturing the retrobulbar venous plexus under isoflurane anesthesia. Blood samples from the adult males and the PND 13 pups were assessed for serum levels for thyroid hormones.

Sacrifice and pathology:

GROSS PATHOLOGY: Yes
All parental animals were sacrificed by decapitation under isoflurane anesthesia. The exsanguinated animals were necropsied and assessed by gross pathology, special attention being given to the reproductive organs.
The following weights were determined in all animals sacrificed on schedule:
1. Anesthetized animals (final body weight)
2. Epididymides
3. Ovaries
4. Prostate (ventral and dorsolateral part together, fixed)
5. Seminal vesicles with coagulating glands (fixed)
6. Testes
7. Thyroid glands (with parathyroid glands) (fixed)
8. Uterus (with cervix)
The following weights were determined in 5 animals per sex/test group sacrificed on
schedule (females with litters only, same animals as used for clinical pathological
examinations):
1. Adrenal glands (fixed)
2. Brain
3. Heart
4. Kidneys
5. Liver
6. Spleen
7. Thymus (fixed)
All paired organs were weighed together (left and right).

The following organs or tissues of all parental animals were fixed in in 4% neutral-buffered
formaldehyde or in modified Davidson’s solution:
1. All gross lesions
2. Adrenal glands
3. Aorta
4. Bone marrow (femur)
5. Brain
6. Cecum
7. Cervix
8. Coagulating glands
9. Colon
10. Duodenum
11. Epididymides (modified Davidson’s solution)
12. Esophagus
13. Extraorbital lacrimal glands
14. Eyes with optic nerve (modified Davidson’s solution)
15. Femur with knee joint
16. Heart
17. Ileum
18. Jejunum (with Peyer’s patches)
19. Kidneys
20. Larynx
21. Liver
22. Lungs
23. Lymph nodes (axillary and mesenteric)
24. Mammary gland (male and female)
25. Nose (nasal cavity)
26. Ovaries (modified Davidson’s solution)
27. Oviducts
28. Pancreas
29. Parathyroid glands
30. Pharynx
31. Pituitary gland
32. Prostate gland
33. Rectum
34. Salivary glands (mandibular and sublingual)
35. Sciatic nerve
36. Seminal vesicles
37. Skeletal muscle
38. Spinal cord (cervical, thoracic and lumbar cord)
39. Spleen
40. Sternum with marrow
41. Stomach (forestomach and glandular stomach)
42. Testes (modified Davidson’s solution)
43. Thymus
44. Thyroid glands
45. Trachea
46. Urinary bladder
47. Uterus
48. Vagina

The uteri of all cohabited female F0 parental animals were examined for the presence and number of implantation sites. The uteri of apparently nonpregnant animals or empty uterus horns were placed in 1% ammonium sulfide solutions for about 5 minutes in order to be able to identify early resorptions or implantations (SALEWSKI E (1964)). Then the uteri were rinsed carefully in physiologic salt solution (0.9 % NaCl). When the examinations were completed, the uteri were transferred to the Pathology Laboratory for further processing.

Pups
On PND 13, one selected male and one female pup per litter was sacrificed under isoflurane anesthesia by decapitation. Blood was sampled for determination of thyroid hormone concentrations. Thyroid glands/parathyroid glands were fixed in neutral buffered 4% formaldehyde solution and were transferred to the Pathology Laboratory for possible further processing.

HISTOPATHOLOGY: Yes
Fixation was followed by histotechnical processing and examination by light microscopy.
Special attention was given to the stages of spermatogenesis and histopathology of interstitial testicular cell structure. The organs were trimmed according to the “Revised guides for organ sampling and trimming in rats and mice” (Ruehl-Fehlert et al., 2003; Kittel et al., 2004; Morawietz et al., 2004). A correlation between gross lesions and histopathological findings was attempted. Whenever in the ovary the diagnosis: „no abnormalities detected” was used that implies that all different stages of functional bodies (especially corpora lutea) were present and normal.

Statistics:

Means, medians, standard deviations and deviation vs control of each test group were calculated for several parameters.
For parameters with bidirectional changes: Non-parametric one-way analysis using KRUSKAL-WALLIS test. If the resulting p-value was equal or less than 0.05, a pairwise comparison of each dose group with the control group was performed using WILCOXON-test (twosided) for the hypothesis of equal medians.
For parameters with unidirectional changes: Pairwise comparison of each dose group with the control group using the WILCOXON-test (one-sided) for the hypothesis of equal medians
Throughout the chapter "results", the term "significant" implies that the inter-group differences have attained statistical significance (p 􀂔 0.05) when compared with the control group.

Clinical signs:

no effects observed

Mortality:

no mortality observed

Body weight and weight changes:

effects observed, non-treatment-related

Description (incidence and severity):

No test substance-related alterations of mean body weights were observed for male and female animals of test groups 1-3 (120, 400 and 1200 mg/kg bw/d) when compared to the control group.
The body weight change of test group 3 (1200 mg/mg bw/d) was significantly increased during gestation days 7-14. This isolated increase of body weight change in females at one time point was assessed not related to treatment. It is more likely to be related to the larger mean litter size of 13.6 pubs delivered per dam observed in this test group in comparison to control 11.3 pubs delivered per dam.

Food consumption and compound intake (if feeding study):

effects observed, treatment-related

Description (incidence and severity):

Food consumption was significantly increased in males of test group 3 (1200 mg/kg bw/d; 10.3%) on study day 7 during premating as well as in males of test group 3 between study days 0-13 (9.1%). It could not be excluded that this increases of food consumption was treatment-related, however, this alteration was assessed as non-adverse.
Food consumption of the F0 females of test group 3 (1200 mg/kg bw/d) as well as males and females in dose groups 1 and 2 (120 and 400 mg/kg bw/d) was not influenced by the treatment throughout the entire study period.

Food efficiency:

not specified

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

no effects observed

Ophthalmological findings:

not specified

Haematological findings:

no effects observed

Clinical biochemistry findings:

effects observed, non-treatment-related

Description (incidence and severity):

No treatment-related changes among clinical chemistry parameters were observed.
At the end of the administration period in rats of both sexes of test group 2 (400 mg/kg bw/d) and in females of test group 1 (120 mg/kg bw/d) globulin values were significantly increased.
Additionally, in females of test group 2, total protein and albumin values were significantly higher compared to controls. All changes were not dose-dependent and therefore they were regarded as incidental and not treatment-related.

Urinalysis findings:

not specified

Behaviour (functional findings):

effects observed, non-treatment-related

Description (incidence and severity):

Deviations from "zero values" were obtained in several rats. However, as most findings were equally distributed between test-substance treated groups and controls, without a doseresponse relationship or occurred in single animals only, these observations were considered as incidental.
The following examinations were performed during FOB and are assessed individually:
- Home cage observations: No test substance-related effects were observed.
- Open field observations: No test substance-related effects were observed.
- Sensorimotor tests/reflexes: No test substance-related effects were observed.
- Quantitative Parameters: No test substance-related effects were observed.
Regarding the overall motor activity as well as the individual intervals of observations, no test substance-related deviations were noted for male and female animals.

Immunological findings:

not examined

Organ weight findings including organ / body weight ratios:

no effects observed

Gross pathological findings:

no effects observed

Description (incidence and severity):

All findings were single observations. They were considered to be incidental or spontaneous in origin and without any relation to treatment.

Neuropathological findings:

not specified

Histopathological findings: non-neoplastic:

no effects observed

Description (incidence and severity):

All findings occurred either individually or were biologically equally distributed over control and treatment groups. They were considered to be incidental or spontaneous in origin and without any relation to treatment.
The stages of spermatogenesis in the testes of males of the high dose test group were comparable to those of the controls. In high dose females the different stages of functional bodies in the ovaries were present and comparable to the control animals.
The female animal (No. 101), which was not pregnant as well as the male mating partner (No. 001) did not show relevant histopathological findings.

Histopathological findings: neoplastic:

no effects observed

Other effects:

no effects observed

Description (incidence and severity):

Estrous cycle data revealed regular cycles in the rearing F1 females of all test groups including the control. The mean estrous cycle duration in the different test groups (0-3) ranged from 3.9 to 4.0 days.

Key result

Dose descriptor:

NOAEL

Effect level:

1 200 mg/kg bw (total dose)

Based on:

test mat.

Sex:

male/female

Basis for effect level:

other: highest tested dose (limit dose) wihtout any effects

Critical effects observed:

no

Conclusions:

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 no adverse findings in parental animals and progeny up
to 1200 mg/kg bw/d corresponding to 1007 mg/kg bw/d of 3-Isocyanatomethyl-3,5,5-trimethylcyclohexyl isocyanate, oligomers, reaction products with 1,2-Propanediol, monocarbamate.
Thus, the no observed adverse effect level (NOAEL) for general systemic toxicity, fertility and reproductive performance was 1200 mg/kg bw/d in both sexes of parental animals.
The NOAEL for developmental toxicity in the F1 progeny was 1200 mg/kg bw/d.

Executive summary:

The test substance was administered daily by gavage as a suspension to groups of 10 male and 10 female Wistar rats (F0 animals) at doses of 0, 120, 400 and 1200 mg/kg body weight/day (mg/kg bw/d). The content of the main test compound is 83.9 %, corresponding to 3 -Isocyanatomethyl-3,5,5-trimethylcyclohexyl isocyanate, oligomers, reaction products with 1,2-propanediol, monocarbamate. Therefore, the dose levels of the test substance correspond to the administration of 0, 101, 336, and 1007 mg/kg bw/d of the four main components. Control animals were dosed daily with the vehicle only (corn oil Ph.Eur.8.0).

The duration of treatment covered a 2-week premating period and mating period in both sexes, (mating pairs were from the same dose group), one day 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.

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 no adverse findings in parental animals and progeny up to 1200 mg/kg bw/d corresponding to 1007 mg/kg bw/d of 3-Isocyanatomethyl-3,5,5 -trimethylcyclohexyl isocyanate, oligomers, reaction products with 1,2-Propanediol, monocarbamate.

Thus, the no observed adverse effect level (NOAEL) for general systemic toxicity, fertility and reproductive performance was 1200 mg/kg bw/d in both sexes of parental animals. The NOAEL for developmental toxicity in the F1 progeny was 1200 mg/kg bw/d.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

NOAEL

1 200 mg/kg bw/day

Study duration:

subacute

Species:

rat

Quality of whole database:

The whole database is of good quality.

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

Additional information

The substance was administered daily by gavage as a suspension to groups of 10 male and 10 female Wistar rats (F0 animals) at doses of 0, 120, 400 and 1200 mg/kg body weight/day (mg/kg bw/d). The content of the main test compound is 83.9 %, corresponding to 3 -Isocyanatomethyl-3,5,5-trimethylcyclohexyl isocyanate, oligomers, reaction products with 1,2-propanediol, monocarbamate. Therefore, the dose levels of the test substance correspond to the administration of 0, 101, 336, and 1007 mg/kg bw/d of the four main components. Control animals were dosed daily with the vehicle only (corn oil Ph.Eur.8.0).

The duration of treatment covered a 2-week premating period and mating period in both sexes, (mating pairs were from the same dose group), one day 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.

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 no adverse findings in parental animals and progeny up to 1200 mg/kg bw/d corresponding to 1007 mg/kg bw/d of 3-Isocyanatomethyl-3,5,5 -trimethylcyclohexyl isocyanate, oligomers, reaction products with 1,2-Propanediol, monocarbamate.

Thus, the no observed adverse effect level (NOAEL) for general systemic toxicity, fertility and reproductive performance was 1200 mg/kg bw/d in both sexes of parental animals. The NOAEL for developmental toxicity in the F1 progeny was 1200 mg/kg bw/d.

Justification for classification or non-classification

As there is no indication for systemic toxicity after repeated administration, classification is not warranted according to the EC Directive (No.93/21/EEC) and CLP (No. 1272/2008 of 16 December 2008).