Registration Dossier

Administrative data

Endpoint:
two-generation reproductive toxicity
Remarks:
based on test type (migrated information)
Type of information:
experimental study
Adequacy of study:
key study
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: GLP and well conducted study performed by Environmental Health Research and Testing Inc.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1986

Materials and methods

Principles of method if other than guideline:
The study was performed using the NTP Fertility Assessment by Continuous Breeding (FACB) system. It consists of four related tasks as follows: 1. dose finding. 2. continuous breeding phase. 3. identification of the affected sex. 4 offspring assessment.
GLP compliance:
yes
Limit test:
no

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
Source: Dow Chemical Company, Lot No.: MM05137-636, Purity: Approx 87.3%, Identity of impurities: 2,2-bis(hydroxymethyl)-1-bromo-3-hydroxypropane (6.7%), 2,2-bis(bromomethyl)-1-bromo-3-hydroxypropane (5.5%), 3,3-bis(bromomethyl) oxetane (0.5%), water (3±0.1%).

Test animals

Species:
mouse
Strain:
CD-1
Sex:
male/female
Details on test animals and environmental conditions:
Parental: 20 male, 20 female per dose. Age:11 weeks
F1: 20 male, 20 female per dose. Age 64-84 days

Administration / exposure

Route of administration:
oral: feed
Vehicle:
other: substance was administered in feed
Details on mating procedure:
Task 2: 1 male and 1 female per cage. Cohabitation for 14 weeks.
Task 3: 1 male and 1 female per cage. Cohabitation until vaginal plug was detected or for a maximum of 7 days
Task 4: 1 male and 1 female per cage. Cohabitation continued for seven days or until a copulatory plug was found.
Details on analytical verification of doses or concentrations:
Range finding study Task 1: 0, 0.025, 0.05, 0.1, 0.25, 0.5 % w/w
Cohabitation study Task 2: 0, 0.1, 0.2, 0.4 % w/w
Crossover Mating Study Task 3: No chemical treatment during the mating period. 0, 0.4 % w/w during post-mating holding period.
Second Generation Study Task 4: 0, 0.1, 0.2, 0.4 % w/w.
Duration of treatment / exposure:
Premating exposure period for males: Parental (Task 2): 7 days
F1 (Task 4): 64-84 days

Premating exposure periods for females: Parental (Task 2): 7 days
F1 (task 4): 64-84 days.
Frequency of treatment:
Daily, ad libitum
Details on study schedule:
Task 1: 2 weeks
Task 2: 1 week pre-treatment, 14 weeks cohabitation, and 3 weeks holding period.
Task 3: 1 week cohabitation (maximum), and 3 weeks holding period.
Task 4: 74±10 days premating, 7 days (maximum cohabitation), and 3 weeks holding period.
No. of animals per sex per dose:
Parental: 20 male, 20 female per dose. Age 11 weeks
F1: 20 male, 20 female per dose. Age: 64-84 days.
Details on study design:
Control group:
Task 1: 8 males, 8 females; vehicle control
Task 2: 40 males, 40 females; vehicle control
Task 3: 20 males, 20 females; vehicle control
Task 4: 20 males, 20 females; vehicle control

Standardization of litters: No

Examinations

Parental animals: Observations and examinations:
Task 2 parental body weights were measured on days-7 (start of dosing), 0 (start of cohabitation), 7, 28, 84 and 112.
Oestrous cyclicity (parental animals):
Studied during Task 3
Sperm parameters (parental animals):
Sperm motility, sperm counts per "g" caudal tissue, and the incidence of abnormal sperm were examined at the end of Task 3
Litter observations:
At least twice per day: Loss of hair, diarrhoea, wounds, hyperactivity, inactivity, tearing or ocular discharge, paralysis, nasal discharge, blood in cage and or/ on animal, abnornal posture or death.
Postmortem examinations (offspring):
Female-liver, kidney, lymph nodes, mammary glands, ovary, oviduct, uterus, vagina, urinary bladder and skeletal muscle; Male-kidney, liver, epididymis, prostate gland, seminal vesicles, skin, testes and urinary bladder.
Statistics:
The Cochran-Armitage test was used in Task 2 to assess dose-related trends in fertility. Days between litters were evaluated by Shirley’s test. In Task 3 a c 2 test for homogeneity was used to test for an overall difference in fertility among the cross-mated groups. Pairwise comparisons between control and dosed groups were determined by the Fisher’s exact test. Dose group means for the proportion of live pups and sex ratio of pups were tested for overall differences by the Kruskal-Wallis test and for ordered differences by the Jonckheere test. Pairwise comparisons of treatment group means were determined by the Wilcoxon-Mann-Whitney U test. Differences in average pup weight were investigated using analysis of covariance (ANCOVA), using avaerage litter size inclusive of live and dead pups as covariant. Pairwise comparisons were performed using a two-tailed t test. For organ weights, analysis of covariance was performed to determine least squares treatment group means, which were then tested for overall and pairwise equality by two-sided F and t tests, respectively. The Kruskal-Wallis and Wilcoxon-Mann-Whitney U tests were also employed in the analysis of unadjusted body and organ weights.

Results and discussion

Results: P0 (first parental animals)

General toxicity (P0)

Clinical signs:
no effects observed
Mortality:
no mortality observed
Body weight and weight changes:
effects observed, treatment-related
Description (incidence and severity):
After 14 weeks of treatment the weight gain for males in the 0, 0.1, 0.2, and 0.4 % dose groupd was 12, 10, 8, and 0% respectively. In fact, mice in th 0.4% dose group lost weight during the first few weeks of treatment and later regained it. Animals in all 3 dose groups consistently weighed less than the control group. The difference was most apparent at the 0.4% dose level.
Food consumption and compound intake (if feeding study):
no effects observed
Water consumption and compound intake (if drinking water study):
not examined
Ophthalmological findings:
not examined
Organ weight findings including organ / body weight ratios:
no effects observed
Histopathological findings: non-neoplastic:
effects observed, treatment-related
Other effects:
no effects observed

Reproductive function / performance (P0)

Reproductive function: oestrous cycle:
no effects observed
Reproductive function: sperm measures:
no effects observed
Reproductive performance:
effects observed, treatment-related
Description (incidence and severity):
Significant decrease (p<0.01) in the mean number of litters per fertile pair at the 0.4% BBMP level.
Other reproductive parameters significantly affected (p<0.01) at this dose level were : the total number of live pups (male, female) per litter, the proportion of the pups born alive, and the adjusted live pups weight.
At the 0.2% dose level, both absolute (except for female pups) and adjusted live pups weights were significantly decreased (p<0.05).
BBMP was significantly toxic at 0.2% and 0.4% dose levels as was revealed by the average dam weight by litter.




Details on results (P0)

see attached documet

Effect levels (P0)

Key result
Dose descriptor:
NOEL
Remarks:
F0
Effect level:
0.1 other: %
Based on:
test mat.
Sex:
male/female
Basis for effect level:
reproductive performance

Target system / organ toxicity (P0)

Key result
Critical effects observed:
no

Results: P1 (second parental generation)

General toxicity (P1)

Clinical signs:
no effects observed
Body weight and weight changes:
no effects observed

Reproductive function / performance (P1)

Reproductive function: oestrous cycle:
no effects observed
Reproductive function: sperm measures:
no effects observed
Reproductive performance:
effects observed, treatment-related

Effect levels (P1)

Key result
Dose descriptor:
NOAEL
Effect level:
0.1 other: %
Based on:
test mat.
Sex:
male/female
Basis for effect level:
reproductive performance

Results: F1 generation

General toxicity (F1)

Clinical signs:
not specified
Mortality / viability:
not specified
Body weight and weight changes:
not specified
Sexual maturation:
not specified
Organ weight findings including organ / body weight ratios:
not specified

Details on results (F1)

see attached document

Effect levels (F1)

open allclose all
Key result
Dose descriptor:
NOEL
Remarks:
F0
Generation:
F1
Effect level:
0.1 other: %
Based on:
test mat.
Sex:
male/female
Basis for effect level:
other: reproductive performance
Key result
Dose descriptor:
NOEL
Remarks:
F1
Generation:
F1
Effect level:
0.1 other: %
Based on:
test mat.
Sex:
male/female
Basis for effect level:
other: reproductive performance

Results: F2 generation

General toxicity (F2)

Body weight and weight changes:
effects observed, treatment-related
Description (incidence and severity):
Pups in the 3 dose groups were smaller than the control group at weaning as well as through maturation.
Food consumption and compound intake (if feeding study):
no effects observed
Description (incidence and severity):
There was no apparent difference with respect to average daily feed consumptio in the control and 3 dose groups.
Histopathological findings:
effects observed, treatment-related
Description (incidence and severity):
Kidney and liver

Effect levels (F2)

Key result
Dose descriptor:
NOEL
Remarks:
F1
Generation:
F2
Effect level:
0.1 other: %
Based on:
test mat.
Sex:
male/female
Basis for effect level:
histopathology: non-neoplastic

Overall reproductive toxicity

Reproductive effects observed:
not specified

Applicant's summary and conclusion

Conclusions:
The substance administered in feed at the 0.4% dose level adversely affected reproduction in CD1
mice. Continued treatment at this dose level also resulted in a significant drop in body weight. The crossover mating study showed that it was the reproductive performance of female mice that was affected by treatment with the substance at the 0.4% dose level. The number of live pups per litter delivered by the 0.4% female x control male group being significantly lower than the 0.4% male x control female group. The reproductive performance of second generation CD-1 mice exposed to the substance at the 0.4% dose level was adversely affected with respect to the number of live pups per litter and the adjusted live pup weight. Second generation animals in the 0.4% group weighed less than the control group at weaning, through maturation and at necropsy.