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Toxicological information

Toxicity to reproduction

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Administrative data

Endpoint:
one-generation reproductive toxicity
Remarks:
based on test guideline
Type of information:
experimental study
Adequacy of study:
key study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: GLP compliant, near guideline study, read-across.
Justification for type of information:
Bis (2-ethylhexyl) adipate (DEHA) is appropriate for read-across because it is considered as a similar substance, based on similar structure, toxicokinetic and toxicological profile useful for this interpolation (please see also read-across justification).

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1988

Materials and methods

Test guideline
Qualifier:
equivalent or similar to
Guideline:
OECD Guideline 415 [One-Generation Reproduction Toxicity Study (before 9 October 2017)]
Deviations:
no
GLP compliance:
yes
Limit test:
no

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
Purity: 99.2% w/w
Batch number: Y02259/003/001

Test animals

Species:
rat
Strain:
Wistar
Sex:
male/female
Details on test animals and environmental conditions:
TEST ANIMALS
- Source: Specific Pathogen Free (SPF) colony at the Alderley Park Breeding Unit, ICI
- Age at study initiation: 28 days
- Weight at study initiation: (P) Males: 72.5 g; Females: 71.1 g
- Housing: 2 females or 1 male per cage
- Diet (e.g. ad libitum): CTI diet supplied by Special Diets Servies Limited
- Water (e.g. ad libitum): filtered tap water
- Acclimatisation period: 6-7 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 19 - 21
- Humidity (%): 45-60
- Air changes (per hr): 15 - 25
- Photoperiod (hrs dark / hrs light): 12 /12

IN-LIFE DATES: From: 3-4 August 1987 To: 12 January 1988

Administration / exposure

Route of administration:
oral: feed
Vehicle:
other: hexane
Details on exposure:
DIET PREPARATION
- Mixing appropriate amounts with (Type of food):
Dose level 300 ppm: 9.07g/30 kg
Dose level 1800 ppm: 54.44g/30 kg
Dose level 12000 ppm: 362.90g/30 kg
Details on mating procedure:
- M/F ratio per cage: 1 male and 2 female per cage
- Length of cohabitation: 10 days
- Proof of pregnancy: vaginal smear were examined daily
- After 10 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): separately
Analytical verification of doses or concentrations:
yes
Details on analytical verification of doses or concentrations:
Mean concentrations within 2% of target concentration for all groups. DEHA was not detected in any control diet (detection limit 10ppm). Chemical stability of DEHA in diet was determined on three batches of diet at nominally 300 ppm and 12000 ppm. Satisfactory chemical stability was established.
Homogeneity of DEHA in diet mixtures was satisfactorily demonstraded on the first diet batch at nominally 300 and 12000 ppm DEHA.
Duration of treatment / exposure:
10 weeks
Frequency of treatment:
The rats in each generation were fed experimental diets continuously until termination.
Doses / concentrationsopen allclose all
Remarks:
Doses / Concentrations:
0, 300, 1800, 12000 ppm
Basis:
nominal in diet
Remarks:
Doses / Concentrations:
0, 28, 170, 1080 mg/kg
Basis:
nominal in diet
No. of animals per sex per dose:
30 females and 15 males per group in total 4 groups.
Control animals:
yes, plain diet
Details on study design:
According to randomisation the rats where housed
Positive control:
no

Examinations

Parental animals: Observations and examinations:
CAGE SIDE OBSERVATIONS: Yes, at least once daily

DETAILED CLINICAL OBSERVATIONS: Yes, once weekly

BODY WEIGHT: Yes, of all rats were recored at weekly intervals throughout the premating period.

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, each cage of rats was recorded throughout the premating periods and calculated on a weekly basis. The food utilisation value per cage was calculated as the weight gained by the animals in the cage per 100g of food eaten.
Oestrous cyclicity (parental animals):
no data
Sperm parameters (parental animals):
no data
Litter observations:
STANDARDISATION OF LITTERS
A count of all live and dead pups was made within 24 hrs (day 1), at days 5, 11, 22, 29 and 36 post partum. The sexes of the pups were also recorded at these times.
Postmortem examinations (parental animals):
SACRIFICE
All animals at scheduled kills and those killed during the study were anaesthetised by inhalation of halothane BP vapour and killed by exsanguination. All surviving males were killed after completion of mating. All females were killed after weaning thier litters.

Histological examination: Cervix, Epididymis, Liver, Mammary gland, Ovary, Prostate, Seminal vesicle, Testis, Uterus, Abnormal tissues.
Postmortem examinations (offspring):
All pups were killed as soon as possible after Day 36 post partum.

Histological examination: Cervix, Epididymis, Liver, Mammary gland, Ovary, Prostate, Seminal vesicle, Testis, Uterus, Abnormal tissues.
Statistics:
Mean bodyweight gain, food consumption and food utilisation during the premating period, female bodyweight gain during pregnancy, parental liver weights and pup (litter) bodyweight gain until Day 36 post partum.
Reproductive indices:
Mean lenght of gestation, mean pre-coital interval
Offspring viability indices:
Mean live born index, mean survival index, mean litter size, total litter weight and whole litter losses.

Results and discussion

Results: P0 (first parental animals)

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
Gross pathological findings:
no effects observed
Histopathological findings: non-neoplastic:
no effects observed
Other effects:
effects observed, treatment-related

Reproductive function / performance (P0)

Reproductive function: oestrous cycle:
not specified
Reproductive function: sperm measures:
not specified
Reproductive performance:
no effects observed

Details on results (P0)

TEST SUBSTANCE INTAKE
There was a slight increase in food consumption in males dosed with 12000ppm DEHA from 6-10 weeks of the study, the effect being statistically significant at weeks 6-9. Food utilisation was slightly less efficients overall for males receiving 12000ppm DEHA.

ORGAN WEIGHTS
An increase in liver weight was observed for both male and female parents receiving 12000ppm DEHA. No other groupp treatment group was effected. This increase in liver weight has been reported previously and is associated with peroxisome proliferation (Moody and Reddy 1978).

Effect levels (P0)

Key result
Dose descriptor:
NOAEL
Effect level:
ca. 170 mg/kg bw/day (nominal)
Sex:
male/female
Basis for effect level:
other: increased absolute liver weights, and reduced body weight gain in females

Results: F1 generation

General toxicity (F1)

Clinical signs:
no effects observed
Mortality / viability:
no mortality observed
Body weight and weight changes:
effects observed, treatment-related
Sexual maturation:
not specified
Organ weight findings including organ / body weight ratios:
no effects observed
Gross pathological findings:
no effects observed
Histopathological findings:
no effects observed

Details on results (F1)

BODY WEIGHT
Mean pup weight gain and total litter weight for both male and female offspring receiving 12000ppm DEHA were reduced throughout the whole of the post partum phase. There was no effect on either male or female pup weight gain in any other dose group in comparison with the control animals.

Effect levels (F1)

Key result
Dose descriptor:
NOAEL
Generation:
F1
Effect level:
ca. 170 mg/kg bw/day (nominal)
Sex:
male/female
Basis for effect level:
other: see 'Remark'

Overall reproductive toxicity

Reproductive effects observed:
not specified

Applicant's summary and conclusion