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Toxicological information

Toxicity to reproduction

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Administrative data

Endpoint:
two-generation reproductive toxicity
Type of information:
experimental study
Adequacy of study:
key study
Study period:
2006
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: Well documented, according to accepted guidelines

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2006
Report date:
2006

Materials and methods

Test guideline
Qualifier:
according to guideline
Guideline:
OECD Guideline 416 (Two-Generation Reproduction Toxicity Study)
Version / remarks:
reliability based on 2001 guideline
Deviations:
no
GLP compliance:
yes
Remarks:
GLP statement not signed or dated
Limit test:
no

Test material

Constituent 1
Chemical structure
Reference substance name:
4-tert-butylphenol
EC Number:
202-679-0
EC Name:
4-tert-butylphenol
Cas Number:
98-54-4
Molecular formula:
C10H14O
IUPAC Name:
4-tert-butylphenol
Details on test material:
- Name of test material (as cited in study report): para-tertiary butylphenol, UCAR Butylphenol 4T-Flake (para tert-Butyl Phenol), PTBP.
- Physical state: White flakes.
- Analytical purity: Not reported.
- Lot/batch No.: Charge No. 496500; BRRC Sample No. 48-186.
- Expiration date of the lot/batch: Not reported.
- Stability under test conditions: Not reported.
- Storage condition of test material: Not reported.

Test animals

Species:
rat
Strain:
Sprague-Dawley
Sex:
male/female
Details on test animals or test system and environmental conditions:
TEST ANIMALS
- Source: Charles River UK Ltd. Margate, Kent, UK
- Age at study initiation: (P) 4 wks
- Weight at study initiation: (P) Males: 93-123 g; Females: 95-141 g
- Fasting period before study: None
- Housing: (P) animals were initially housed 2 per cage in polypropylene cages with stainless steel grid bottoms and mesh tops and measured ca 58 x 38.5 x 20 cm. Male and female cages were racked separately. Three days prior to mating, the males were transferred to individual grid bottomed cages. For mating, the females were transferred to the cage of the appropriate co-group male. Mated females were transferred to individual solid-bottomed cages, measuring ca 42 x 27 x 20 cm, in which sterilised white wood shavings were provided as bedding. Just prior to anticipated parturition, some white paper tissue was provided as nesting material. Females retained this type of caging until termination. F1 animals retained after weaning were housed 2 per cage in ca 42 x 27 x 20 cm grid bottomed cages, sexes separate. At a convenient time, the animals were transferred to larger cages as previously described. Three days prior to mating, the F1 males were transferred to individual grid bottomed cages. The F1 animals then followed the same caging regime as described for the (P) animals. Cages, absorbent papers and water bottles were changed at regular intervals, as appropriate. Nesting material was changed when it became unacceptably soiled and was withdrawn at a suitable time during lactation. Clean wood shavings were provided at each change of solid-bottomed cages.
- Use of restrainers for preventing ingestion (if dermal): Not applicable
- Diet (e.g. ad libitum): Rat and Mouse Breeder Diet No. 3 (Expanded) SQC (ground), was supplied by Special Diets Services Limited, Stepfield, Witham, Essex, UK, and was available to the animals ad libitum.
- Water (e.g. ad libitum): The animals had access to domestic mains water ad libitum.
- Acclimation period: 13 days


ENVIRONMENTAL CONDITIONS
- Temperature (°C): 20 +/- 2
- Humidity (%): 50 +/- 15
- Air changes (per hr): (min) 15
- Photoperiod (hrs dark / hrs light): 12/12


Administration / exposure

Route of administration:
oral: feed
Type of inhalation exposure (if applicable):
other: Not applicable
Vehicle:
acetone
Details on exposure:
PREPARATION OF DOSING SOLUTIONS:

DIET PREPARATION
- Preparation of diet: An appropriate weight of premix, at a concentration of 100000 ppm., was prepared by adding the required weight of test item to the corresponding weight of untreated diet. Diets for the Intermediate and High dose animals were formulated by direct dilution of the premix with untreated diet. The Control diet was prepared in the same manner by dilution of the control premix with untreated diet such that the diet contained the same proportion of the premix as the High dose diet. The Low dose diet was prepared by diluting the High dose preparation with untreated diet. Each final formulation was blended for at least 20 min on a Winkworth change drum mixer. Fresh diets were prepared as required but no less frequently than weekly during the study. Each mixed batch was stored in a closed container at ambient temperature and used within the 10 day stability period.



VEHICLE
- Justification for use and choice of vehicle (if other than water): Acetone was used to incorporate the test item into the premix; the incorporation ratewas 100 mL of solvent per kg premix. The premix was mixed for ca 1h on a Hobart planetary mixer with fan assisted venting, to aid removal of acetone. A control premix was prepared using acetone and blank diet in the same proportion.
Details on mating procedure:
- M/F ratio per cage: 1:1
- Length of cohabitation: until pregnancy occured to a maximum of 14 days
- Proof of pregnancy: copulatory plug and/or sperm in the vaginal smear referred to as day 0 of pregnancy
- After 14 days of unsuccessful pairing replacement of first male by another male with proven fertility.
- Further matings after two unsuccessful attempts: no
- After successful mating each pregnant female was caged (how): individual solid bottomed cage
Analytical verification of doses or concentrations:
yes
Details on analytical verification of doses or concentrations:
Analysis of formulated diets was undertaken with regard to concentration and homogeneity. It was detailed in the protocol that samples would be analysed on 6 occasions, but in response to some values being outside ± 10% of the nominal, additional samples were taken to investigate the cause of the divergence. As a result formulated diets were sampled on 10 occasions (one set taken as contingency) and analysed on 9 occasions during the study treatment period, and the premix on 2 occasions. The procedures for additional sampling were standard procedures and considered best practice; the deviation from the protocol did not affect the integrity of the study. On each occasion, triplicate samples were withdrawn from each formulation containing test item, and the Control diet. The analyses were undertaken at Charles River Laboratories, using a method supplied by the Sponsor and previously validated in the Charles River Laboratories under a separate protocol and contract (Inveresk Project No. 421646).
Duration of treatment / exposure:
P animals were treated for 10 weeks prior to mating, commencing at ca 6 weeks of age. Treatment continued for both sexes throughout mating, gestation and lactation until termination. The selected F1 animals were treated for at least 10 weeks after weaning, prior to mating. Treatment was then continued for both sexes throughout mating, gestation and lactation until termination of the F1 adults and F2 weanlings.
Frequency of treatment:
daily
Details on study schedule:
At Day 21 of lactation, a group size of 24 male and 24 female weanlings was constituted, nominally by selection of one male and one female from 24 appropriate litters. For each sex, a pup was randomly selected from that litter. The selected animals were earmarked, although actual separation from the mother occurred later, at Day 24 of lactation. The cages of selected weanlings were racked by treatment group and vertically throughout the rack. Control animals were housed on a separate rack. Pups that were not selected for post-weaning assessment remained with their mother until termination.
Doses / concentrations
Remarks:
Doses / Concentrations:
0, 800, 2500, 7500 ppm
Basis:
nominal in diet
No. of animals per sex per dose:
28 (P) and 24 (F1)
Control animals:
yes, concurrent vehicle
Details on study design:
- Rationale for animal assignment; random
Positive control:
None

Examinations

Parental animals: Observations and examinations:
CAGE SIDE OBSERVATIONS: Yes
- Time schedule: twice daily

DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule: weekly

BODY WEIGHT: Yes
- Time schedule for examinations: weekly

FOOD CONSUMPTION AND COMPOUND INTAKE (if feeding study):
- Food consumption for each animal determined and mean daily diet consumption calculated as g food/kg body weight/day: Yes
- Compound intake calculated as time-weighted averages from the consumption and body weight gain data: Yes

WATER CONSUMPTION AND COMPOUND INTAKE (if drinking water study): No
Oestrous cyclicity (parental animals):
Over the 2 weeks prior to pairing for mating of the P and F1 animals, vaginal lavages were taken early each morning and the stage of oestrus observed was recorded.
Sperm parameters (parental animals):
The tip of the cauda epididymis was placed in Medium 199 containing 0.2% BSA and HEPES. The sperm was allowed to `swim out¿ into the medium. An appropriate dilution of the sperm suspension was examined using a Hamilton Thorne sperm motility analyser; sufficient replicates to provide 200 motile sperm were assessed (except where it was obvious that motility was compromised for that animal). The remaining portion of the cauda epididymis was minced and suspended. Dilutions of that suspension were assessed using a haemocytometer to obtain a total sperm count which was expressed per cauda epididymis and per gram of cauda epididymis. In addition a smear of the suspension was prepared and stained with eosin. From the Control and High dose animals, at least two hundred (200-207) sperm per animal were evaluated for morphological abnormalities using criteria described by Wyrobek and Bruce (1975). This deviation from the protocol did not affect the integrity of the study. One testis was minced and suspended in appropriate dilutions to allow the number of homogenisation resistant spermatids to be counted using a haemocytometer.
Litter observations:
STANDARDISATION OF LITTERS
- Performed on day 4 postpartum: no

PARAMETERS EXAMINED
The following parameters were examined in F1/F2 offspring: number and sex of pups, stillbirths, live births, postnatal mortality, presence of gross anomalies, weight gain, physical or behavioural abnormalities, other:

GROSS EXAMINATION OF DEAD PUPS:
yes, for external and internal abnormalities; possible cause of death was determined for pups born or found dead
Postmortem examinations (parental animals):
SACRIFICE
- Male animals: All surviving animals
- Maternal animals: All surviving animals


GROSS NECROPSY
- All P and F1 parent animals external examination followed by macroscopic examination of the tissues and organs of the cranial, thoracic and abdominal cavities in situ. Any gross lesions were described in terms of location, size, shape, colour, consistency, number and any other relevant characteristics. Representative samples of abnormal tissues were taken and fixed in neutral buffered 10% formalin. The reproductive tracts of all females were examined for signs of implantation, the number of any implant sites present being recorded. The following organs were fixed (in neutral buffered formalin unless otherwise specified). Weights were taken, where indicated, prior to fixation: Ovaries: weighed individually, Uterus (with oviducts and cervix): weighed, Vagina, Testes: weighed individually; left testis fixed in Bouin¿s fluid, right testis submitted for sperm evaluation, Epididymides: weighed individually; right cauda epididymis submitted for sperm evaluation, Seminal vesicles and coagulating glands: combined weight recorded, Prostate: weighed, Pituitary gland: weighed, Brain: weighed, Liver: weighed, Kidneys: weighed individually, Spleen: weighed, Thyroid glands: weighed individually after fixation, and Adrenal glands: weighed individually. For paired organs, the report presents a combined weight. Carcasses were discarded following these procedures.


HISTOPATHOLOGY
-Conducted on all adult animals in the control and high dose groups of the P and F1 generation and all low and intermediate animals that failed to mate or demonstrated any other findings considered to be indicative of reduced fertility. In addition, in response to findings noted in the high dose animals, the vagina and ovary were assessed in all low and intermediate animals. The following tissues were processed; sections were cut 4-6 Mm thick, stained with haematoxylin and eosin (H&E) and evaluated by light microscopy: Ovaries (5 representative sections per ovary), Uterus (with oviucts and cervix), Vagina, Left testis (transverse section), Left epididymis, Seminal vesicles, and coagulating glands, Prostate Pituitary gland, and Adrenal glans. Additionally, a Periodic Acid Schiff and Haematoxylin (PAS-H) stained section was prepared from the left testis.
Postmortem examinations (offspring):
Offspring (pre-weaning) found dead or killed on or after day 14 of lactation were necropsied. This consisted of external examination followed by macroscopic examination of the tissues and organs of the cranial, thoracic and abdominal cavities in situ. Samples of any grossly abnormal tissues were preserved in 10% formalin. The carcasses were then discarded. For offspring found dead or killed before day 14 of lactation, where practicable, these animals were sexed, then checked for the presence of milk in the stomach and for the presence of any externally visible abnormalities. Any abnormal pups were, where practicable, fixed in methylated ethyl alcohol. Externally normal decedents were discarded. For weanlings not selected as parents of a subsequent generation, 3 male and 3 female pups from each litter (where they were available) were necropsied. This consisted of external examination followed by macroscopic examination of the tissues and organs of the cranial, thoracic and abdominal cavities in situ. Sample of any grossly abnormal tissues were preserved in 10% formalin. From one of the 3 pups of each sex, the weights of the brain, spleen and thymus were recorded, and these organs were preserved. The carcasses were then discarded.
Statistics:
Where required in support of interpretation, tests were applied to determine the statistical significance of observed differences between Control and groups receiving test item. All statistical tests were two-sided and performed at the 5% significance level using in house software. Pairwise comparisons were performed against the Control group. Body weight and food consumption data of males, and of females prior to mating, were subjected to analysis of variance. Where appropriate, a log or square root transformation was used to stabilise the variances. Where transformation failed to stabilise the variances, the Kruskal-Wallis test was used. Organ weight data was subjected to analysis of variance, and to one-way analysis of covariance using the terminal body weight as the covariate. In circumstances where the variances in the ANCOVA remained heterogenous following log or square root transformations or where it was not possible to perform the F-max test, the untransformed parametric ANCOVA results are reported. Histopathology data were analysed by Fisher¿s Exact Probability test. For other parameters, interpretation was based on inspection of the individual and group values.
Reproductive indices:
No details
Offspring viability indices:
No details

Results and discussion

Results: P0 (first parental generation)

General toxicity (P0)

Clinical signs:
no effects observed
Body weight and weight changes:
effects observed, treatment-related
Food consumption and compound intake (if feeding study):
effects observed, treatment-related
Organ weight findings including organ / body weight ratios:
effects observed, treatment-related
Histopathological findings: non-neoplastic:
effects observed, treatment-related
Other effects:
effects observed, treatment-related

Reproductive function / performance (P0)

Reproductive function: oestrous cycle:
no effects observed
Reproductive function: sperm measures:
no effects observed
Reproductive performance:
no effects observed

Details on results (P0)

CLINICAL SIGNS AND MORTALITY (PARENTAL ANIMALS)
There were no clinical observations considered to be related to treatment

BODY WEIGHT AND FOOD CONSUMPTION (PARENTAL ANIMALS)
-Parents; At 7500 ppm there was a decrease in weight gain seen in P animals over the first week of treatment. The overall weight gain of the animals over the treatment period (prior to mating) was ca 70% of the Control weight gain, although absolute body weight was generally 80-90% of to Controls. At 2500 ppm in both sexes and 800 ppm in females, there was a slight but similar decrease in weight gain, compared to the higher dose. There were no clear effects of treatment in males at 800 ppm
-F1 Parents; At 7500 p.p.m. the mean body weight of weaned animals (nominal Week 4) was 79% of the Control weight in males and 84% of the Control weight in females. By the end of the treatment period (prior to mating for females) body weight was still ca 80% of the Controls¿ body weight; weight gain throughout was lower than that of the Controls (ca 80%). At 2500 p.p.m. and 800 p.p.m. the mean body weight of weaned animals (nominal Week 4) was 92% of the Controls for males and 91% and 94% for females. There were no clear effects of treatment on body weight gain over the treatment period.


TEST SUBSTANCE INTAKE (PARENTAL ANIMALS)
-At 7500 p.p.m. food consumption was notably reduced in the first week of treatment. The consumption during that week was 71 % of the Controls for males and 67% of the Controls for the females. For both sexes food consumption generally remained lower than the Controls for the remainder of the treatment. During gestation and lactation consumption was lower than the Controls. Minor changes in consumption in the males at 2500 p.p.m were too small to attribute to treatment, but in females there was a reduction in the first week of treatment followed by a marginal divergence from Controls during Weeks 5-8. There was also a slight reduction during the first week of gestation only. At 800 p.p.m. food consumption was essentially similar to Controls in both sexes.

REPRODUCTIVE FUNCTION: ESTROUS CYCLE (PARENTAL ANIMALS)
-The stages of the oestrus cycles and their mean duration were similar in all groups

REPRODUCTIVE FUNCTION: SPERM MEASURES (PARENTAL ANIMALS)
-There were no effects on the sperm motility, count or morphology at any of the dose levels applied, or in either generation. A lower cauda weight and testes weight in F1 animals was considered most likely to reflect the lower body weight, and did not affect any of the counts.

REPRODUCTIVE PERFORMANCE (PARENTAL ANIMALS)
- There were no clear effects of treatment on mating performance, fertility or duration of gestation in either generation

ORGAN WEIGHTS (PARENTAL ANIMALS)
-Parents; At 7500 p.p.m. a number of organ weights in males were statistically significantly lower than in Controls. However the lower body weight was also statistically significant (P<0.001), and following covariance analysis, none of the organs weights that were originally lower than Controls, achieved significance. Kidney weight was statistically higher than the Controls following covariance analysis. At 2500 p.p.m. spleen weight was slightly reduced compared to Controls and achieved statistical significance (P<0.05), but following covariance analysis these findings were no longer evident. At 7500 and 800 p.p.m. the slightly higher liver weights attained statistical significance after covariance analysis but these changes were too small to be attributed to treatment. Similar findings to those seen in the males were noted in females at 7500 p.p.m., with a number of absolute weights being lower than Controls. However after covariance analysis, only decreases in adrenal gland, ovary and pituitary gland weights remained, and were significant (P<0.001) for adrenals and ovaries.
- Parents; The F1 males treated at 7500 p.p.m. reproduced the findings of the males in the F0 generation with a number of organ weights and the body weight being statistically significantly lower than Controls; spleen weight at 2500 p.p.m. also achieved significance. None of these findings were statistically significant following covariance analysis. Kidney weight was higher than the Controls, although it did not attain significance, following covariance analysis. There were no other effects on organ weights at 2500 p.p.m., and there were none at 800 p.p.m in either the F0 or F1 males. In the F1 females treated at 7500 p.p.m. all of the mean organ weights (with the exception of the liver weight) and the body weight were lower than Controls. Of these parameters only the decrease in thyroid weight failed to attain statistical significance. Following covariance analysis a number of organs at 7500 p.p.m. achieved significance, but adrenal gland, brain, kidney, ovaries, pituitary gland and uterus remained lower than Control. There was a significant increase in liver weight. At 2500 p.p.m. adrenal gland and brain weight were lower than Controls, and achieved significance by analysis of variance and covariance. A slightly higher liver weight achieved significance after covariance analysis. There were no other effects on organ weights at 2500 p.p.m., and there were none at 800 p.p.m for either F0 or F1 females

GROSS PATHOLOGY (PARENTAL ANIMALS)
- No significant effects

HISTOPATHOLOGY (PARENTAL ANIMALS)
- In the P animals there was an increase in atrophy of the vaginal epithelium with 7/28 animals at 2500 p.p.m. and 12/28 animals at 7500 p.p.m. affected. The severity of the finding was split approximately equally between minimal and mild. In F0 females at 7500 p.p.m., there was a slightly but significantly greater incidence of females that were in pro-oestrus, and a lower incidence of females in metoestrous. In the F1 generation, the only change that attained statistical significance was an increase in the number of females at 800 p.p.m. In the absence of any changes noted in the vaginal smears prior to mating, these findings were considered to have been incidental.

Effect levels (P0)

Key result
Dose descriptor:
NOEL
Effect level:
800 ppm
Based on:
test mat.
Sex:
male/female
Basis for effect level:
other: reduced pup weight, increased pup mortality, and findings in the ovary and vagina in the higher dose groups.
Remarks on result:
other: Generation: all animals

Results: F1 generation

General toxicity (F1)

Clinical signs:
no effects observed
Mortality / viability:
mortality observed, treatment-related
Body weight and weight changes:
effects observed, treatment-related
Sexual maturation:
effects observed, treatment-related
Organ weight findings including organ / body weight ratios:
effects observed, treatment-related
Gross pathological findings:
no effects observed
Histopathological findings:
effects observed, treatment-related

Details on results (F1)

VIABILITY (OFFSPRING)
- In the P generation the lower number of implant sites and live pups born at 7500 p.p.m. was within the expected variation range for these parameters, but was notably different from the remainder of the groups. In addition, at 7500 p.p.m. pup survival was poor, particularly over Days 0-4 of lactation when 6 different litters had more than 3 pups dying, and in 2 of these litters all pups died. In the F1 generation, the number of implant sites and live pups born was much more variable, but at 7500 p.p.m. the litter size was clearly smaller than that at any other level. The survival of these smaller litters was good and exceeded the performance of the Controls. There were no effects of treatment detected at 800 or 2500 p.p.m. There were no effects on sex ratios in either generation.

CLINICAL SIGNS (OFFSPRING)
-None

BODY WEIGHT (OFFSPRING)
- At 7500 p.p.m., in both generations, pup weights at birth were comparable to those of the Controls but the litter size was slightly smaller, and as a result, litter weight was lower than Controls on Day 1 of lactation. After Day 1 of lactation pup weight gain was less than Control, and by Day 21 of lactation was ca 20% lower than Control weights. Litter weight gain was similarly affected but in the P generation this was also accompanied by a decrease in pup survival. At 2500 p.p.m. pup weight in both generations was lower than Controls from Day 14 of lactation; with a concurrent decrease in litter weight gain also. There were no effects on litter or pup weight at 800 p.p.m. in either generation.

FOOD CONSUMPTION
-At 7500 p.p.m. food consumption in both sexes was lower than the Controls (ca 10% lower) throughout the treatment period. During gestation and lactation consumption was ca 80% of that of the Controls. There were no clear effects at 2500 p.p.m., except a slight reduction during the first week of gestation. Consumption at 800 p.p.m. was essentially similar to Controls.

SEXUAL MATURATION (OFFSPRING)
- In the F1 generation, at 7500 p.p.m. there was an increase in the incidence of primordial follicles with a concurrent decrease in the incidence of growing follicles. At 800 and 2500 p.p.m. the type and incidence of follicles was essentially similar to Controls. On Day 1 of lactation there were no intergroup differences in ano-genital distance, in either generation. On Day 11 of lactation, none of the F1 or F2 male pups had nipple/areolar retention. The raw data for the nipple/areolar retention is retained within the study data archives of Charles River Laboratories but not reproduced in the report. At 7500 p.p.m. vaginal opening and preputial separation occurred 3 and 4 days later than Controls, respectively. Body weight was the same, or slightly lower, than Controls at the time of occurrence suggesting the delay was due to the lower body weight. The age and body weight at preputial separation or vaginal opening in animals treated with 2500 p.p.m. and 800 p.p.m. p-tertbutylphenol were essentially similar to Controls.

ORGAN WEIGHTS (OFFSPRING)
- In males treated at 7500 p.p.m. body weight, spleen and thymus weights were all significantly lower than Control. Brain weight was reduced but did not attain significance. Following covariance analysis none of the findings were evident. There were no effects on organ weight at 800 or 2500 p.p.m. in females treated at 7500 p.p.m. all of the same parameters were lower, with the brain and thymus slightly reduced at 2500 p.p.m. also. Following covariance analysis thymus weights at 2500 and 7500 p.p.m. remained marginally lower.
- As for P males, in males treated at 7500 p.p.m., body weight, brain, spleen and thymus weights were all significantly reduced. Brain weight was reduced but did not attain significance. Following covariance analysis, spleen weight was significantly but slightly lower. In addition, absolute spleen weight at 2500 p.p.m. was also significantly lower, although this was no longer evident after covariance analysis. In females treated at 7500 p.p.m. body weight, brain and spleen weight were statistically significantly lower than Control; thymus weight was also lower but did not attain statistical significance. Following covariance analysis, spleen weight was lower than the Control spleen weight, although the difference did not attain significance. All other weights appeared to be comparable to Controls.

GROSS PATHOLOGY (OFFSPRING)
-

HISTOPATHOLOGY (OFFSPRING)
- increase in atrophy of the vaginal epithelium at 7500 p.p.m.the severity was mild in the majority of animals (79%) with a total of 14/24 animals. However there was no atrophy of the vaginal epithelium recorded at 2500 p.p.m.

OTHER FINDINGS (OFFSPRING)
-Animal 426 (800 p.p.m.) ¿ 1 female pup swelling on ventral abdomen Days 4-14 of lactation
Animal 446 (800 p.p.m.) ¿ 2 female pups with large swellings on head, one killed prematurely due to condition: necropsy findings for both enlarged cranium, cranium contains fluid, soft brain.
Animal 474 (7500 p.p.m.) ¿ 1 female pup small swelling on ventral abdomen, not evident at necropsy.

Effect levels (F1)

Key result
Dose descriptor:
NOEL
Generation:
F1
Effect level:
800 ppm
Based on:
test mat.
Sex:
male/female
Basis for effect level:
other: reduced pup weight in the higher dose groups and increased pup mortality and findings in the ovary and vagina in the highest dose group

Overall reproductive toxicity

Key result
Reproductive effects observed:
not specified

Applicant's summary and conclusion