Dimethyldioctylammonium chloride

Toxicity to reproduction

Administrative data

Endpoint:

two-generation reproductive toxicity

Type of information:

experimental study

Adequacy of study:

key study

Study period:

16 May 1988 - 15 August 1989

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1991

Report date:

1991

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 416 (Two-Generation Reproduction Toxicity Study)

Deviations:

not specified

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

Reference substance 001

Cas Number:

7173-51-5

Test material form:

liquid

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Batch No.of test material: B-1889

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material: room temperature

Test animals

Species:

rat

Strain:

Sprague-Dawley

Sex:

male/female

Administration / exposure

Route of administration:

oral: feed

Vehicle:

unchanged (no vehicle)

Details on exposure:

Twenty eight male and 28 female weanling rats (F0 generation) were exposed to the substance by dietary inclusion for a total of 10-week pre-breed exposure period. Exposures continued through mating, gestation, parturition and lactation. Exposures continued through mating, gestation, parturition and lactation of the second litters.

Details on mating procedure:

Following a 10-week pre-breed exposure period the F0 rats were randomly paired within dose groups for a three week mating period to produce the F1A generation. At least 10 days after the weaning of the F1A litters, the Fo parents were paired again (with different male-female pairing within the dose groups than employed for the F1A breed) for 3 weeks to produce the F1B generation.

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

The concentration of the substance in the test diets was determined using gas chromatography. For the first 4 weeks of teh study, test diets from all diets were analysed for concentrations of the substance prior to administration of the diets to the animals. For the remaining 60 weeks of teh study, all test diets from every fourth preparation were analysed after administration of the diets to the study animals. Homogeneity and stability analyses of the substance in the diets were performed prior to the start of the test diet administration.

Details on study schedule:

Following a 10-week pre-breed exposure period the F0 rats were randomly paired within dose groups for a three week mating period to produce the F1A generation. At least 10 days after the weaning of the F1A litters, the F0 parents were paired again (with different male-female pairing within the dose groups than employed for the F1A breed) for 3 weeks to produce the F1B generation. After the F1B pups were weaned, the F0 animals were necropsied and high dose and control animals were examined for histopathologic lesions. At weaning, 28 F1B weanlings/sex/group were randomly selected as parents of the subsequent generation. Selected F1 parents were exposed to the same dietary concentrations of the substance as their parents for at least 10 weeks. After their pre-breed exposure the F1 animals were paired to produce F2A and F2B offspring.

Doses / concentrations

Doses / concentrations 1

Dose / conc.:

0 ppm

Doses / concentrations 2

Dose / conc.:

300 ppm

Doses / concentrations 3

Dose / conc.:

750 ppm

Doses / concentrations 4

Dose / conc.:

1 500 ppm

No. of animals per sex per dose:

28/sex/dose

Control animals:

yes, plain diet

Details on study design:

Twenty eight F0 rats/sex/dose were bred twice to produce F1A and F1B litters. Selected males and females from F1B litters were used as parents of the F2 generation. Twenty eight F1 pups/sex/dose, exposed to the same dietary concentration of the substance as their parents, were subsequently bred twice to produce F2A and F2B litters.

Examinations

Parental animals: Observations and examinations:

PARAMETERS EXAMINED
The following parameters were examined in F0 to produce F1A/F1B litters and F1 to produce F2A/F2B litters: Mating index (males), mating index (males), fertility index (females) and fertility index (males).

Litter observations:

PARAMETERS EXAMINED
The following parameters were examined in F1A/F1B / F2A/F2B offspring: gestational index, live birth index, 4-day survival index (precull and postcull), 14-day survival index, 21-day survival index, lactation index, 28-day survival index.
[number and sex of pups, stillbirths, live births, postnatal mortality, presence of gross anomalies, weight gain, physical or behavioural abnormalities, anogenital distance (AGD), presence of nipples/areolae in male pups, other:]

GROSS EXAMINATION OF DEAD PUPS:
[no / yes, for external and internal abnormalities; possible cause of death was/was not determined for pups born or found dead.]

Statistics:

The unit of comparison was the male, pregnant female or the litter. Results of the qunatitative continuous variables (e.g. body weights, food consumption, organ weights, etc) were intercompared for the three treatment groups and one control group by use of Levene's test for equal variances; analysis of variance (ANOVA) and t-tests. When Levene's test indicated homogeneous variances and the ANOVA was significant, the pooled t-test was used for pair-wise comparisons. When Levene's test indicated heterogeneous variances, all groups were compared by an ANOVA for unequal variances followed, when necessary, by the separate variance t-test for pairwise comparisons. The significance levels for the t-tests comparisons were corrected by the Bonferroni method. Nonparametric data were statistically evaluated using the Kruskal-Wallis test followed by the Mann-Whitney U test for pairwise comparisons when appropriate. Frequency data were compared using the Fisher's exact test. For all statistical tests, the fidcial limit of 0.5 (two-tailed) was used as the criterion for statistical significance.

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

Description (incidence and severity):

Reduced body weight and body weight gain at the top concentration begining one week after treatment.

Food consumption and compound intake (if feeding study):

effects observed, treatment-related

Description (incidence and severity):

Substantial reductions in food consumption were observed throughout the pre-breed period in F0 animals at the top concentration.

Food efficiency:

not examined

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

not specified

Ophthalmological findings:

not examined

Haematological findings:

not examined

Clinical biochemistry findings:

not examined

Urinalysis findings:

not examined

Behaviour (functional findings):

not specified

Immunological findings:

not examined

Histopathological findings: non-neoplastic:

no effects observed

Histopathological findings: neoplastic:

no effects observed

Reproductive function / performance (P0)

Reproductive performance:

no effects observed

Description (incidence and severity):

Gestational length as well as mating, fertility and gestational indices were unaffected by treatment. Body weights and bodyu weight gains at 300 and 750 ppm were essentially equivalent to control values throughout gestation. Gestational food consumption was unaffected by treatment. There were no differences across the groups for reproductive parameters for F0 parents for the F1A and F1B breeds.

Results: P1 (second parental generation)

General toxicity (P1)

Clinical signs:

effects observed, non-treatment-related

Body weight and weight changes:

effects observed, treatment-related

Description (incidence and severity):

Males and females at 1500 ppm exhibited consistently reduced body weights throughout the entire treatment period. Significant weight gain depression was noted at 1500 ppm.

Food consumption and compound intake (if feeding study):

effects observed, treatment-related

Description (incidence and severity):

Food consumption for the F1 males and females was reduced at 1500 ppm throughout the treatment period. No effects on food consumption were noted in F1 males and females at 300 and 750 ppm.

Food efficiency:

not examined

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

not specified

Ophthalmological findings:

not examined

Haematological findings:

not examined

Clinical biochemistry findings:

not examined

Urinalysis findings:

not examined

Behaviour (functional findings):

not examined

Immunological findings:

not examined

Organ weight findings including organ / body weight ratios:

not examined

Gross pathological findings:

no effects observed

Neuropathological findings:

not examined

Histopathological findings: non-neoplastic:

no effects observed

Histopathological findings: neoplastic:

no effects observed

Reproductive function / performance (P1)

Reproductive performance:

no effects observed

Description (incidence and severity):

Maternal gestational body weights, but not weight gains, were reduced at 1500 ppm.

Effect levels (P1)

1

Key result

Dose descriptor:

NOEL

Effect level:

750 ppm

Based on:

test mat.

Sex:

male/female

Basis for effect level:

body weight and weight gain

2

Key result

Dose descriptor:

NOAEL

Effect level:

1 500 ppm

Based on:

test mat.

Sex:

male/female

Basis for effect level:

reproductive performance

Remarks on result:

not determinable due to absence of adverse toxic effects

Results: F1 generation

General toxicity (F1)

Clinical signs:

effects observed, non-treatment-related

Mortality / viability:

mortality observed, non-treatment-related

Body weight and weight changes:

effects observed, treatment-related

Description (incidence and severity):

Pup body weights and body weight gains were unaffected by treatment though lactational day 7. From day 14 through weaning on lactational day 21, and postweaning, on day 28, body weights of male and female pups at 1500 ppm were reduced. Corresponding body weight gains for lactational days 7-21 and 21-28 (postweaning) were reduced at 1500 ppm. Body weights and weight gains of pups at 750 and 300 ppm were unaffected by treatment.

Food efficiency:

not examined

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

not specified

Ophthalmological findings:

not examined

Haematological findings:

not examined

Clinical biochemistry findings:

not examined

Urinalysis findings:

not examined

Sexual maturation:

not examined

Organ weight findings including organ / body weight ratios:

not examined

Gross pathological findings:

no effects observed

Histopathological findings:

no effects observed

Developmental neurotoxicity (F1)

Behaviour (functional findings):

not examined

Developmental immunotoxicity (F1)

Developmental immunotoxicity:

not examined

Effect levels (F1)

1

Key result

Dose descriptor:

NOEL

Generation:

F1

Effect level:

750 ppm

Based on:

test mat.

Sex:

male/female

Basis for effect level:

body weight and weight gain

2

Key result

Dose descriptor:

NOAEL

Generation:

F1

Effect level:

1 500 ppm

Based on:

test mat.

Sex:

male/female

Basis for effect level:

other: Reproductive performance

Remarks on result:

not determinable due to absence of adverse toxic effects

Results: F2 generation

General toxicity (F2)

Clinical signs:

effects observed, non-treatment-related

Mortality / viability:

mortality observed, non-treatment-related

Body weight and weight changes:

effects observed, treatment-related

Description (incidence and severity):

F2B pup body weights per litter were equivalent through lactational day 4. From lactational day 7 through weaning on day 21, and postweaning, on day 28, body weights of F2B pups at 1500 ppm were reduced. Concurrent F2B pup weight gain reductions were observed at 1500 ppm from day 4-28. There were no observable effects of treatment on body weight at 750 and 300 ppm.

Food consumption and compound intake (if feeding study):

not examined

Food efficiency:

not examined

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

not specified

Ophthalmological findings:

not examined

Haematological findings:

not examined

Clinical biochemistry findings:

not examined

Urinalysis findings:

not examined

Sexual maturation:

not examined

Organ weight findings including organ / body weight ratios:

not examined

Gross pathological findings:

not examined

Histopathological findings:

not examined

Developmental neurotoxicity (F2)

Behaviour (functional findings):

not examined

Developmental immunotoxicity (F2)

Developmental immunotoxicity:

not examined

Effect levels (F2)

1

Key result

Dose descriptor:

NOEL

Generation:

F2

Effect level:

750 ppm

Based on:

test mat.

Sex:

male/female

Basis for effect level:

body weight and weight gain

2

Key result

Dose descriptor:

NOAEL

Generation:

F2

Effect level:

1 500 ppm

Based on:

test mat.

Sex:

male/female

Remarks on result:

not determinable due to absence of adverse toxic effects

Overall reproductive toxicity

Key result

Reproductive effects observed:

no

Lowest effective dose / conc.:

1 500 ppm

Treatment related:

no

Applicant's summary and conclusion

Conclusions:

Exposure of rats to the substance at concentrations of 300, 750 aand 1500 ppm in the diet for two generations resulted in well-defined parental and postnatal toxicity at 1500 ppm without any adverse effects on reproductive performance. The NOEL was 750 ppm for both parents and offspring, indicating that there was no increased risk to the offspring in the absence of indications of adult toxicity.

Executive summary:

The potential of the substance to produce alterations in parental fertility, maternal pregnancy and lactation, and growth and development of the offspring for two generations and two litters per generation was evaluated in Sprague Dawley rats. The substance was administered via the diet at concentrations of 300, 750 aand 1500 ppm. A well-defined parental and postnatal toxicity as evidenced by body weight reductions occurred at 1500 ppm without any adverse effects on reproductive performance. The NOEL was 750 ppm for both parents and offspring, indicating that there was no increased risk to the offspring in the absence of indications of adult toxicity.