Diisooctyl adipate

Toxicity to reproduction

Administrative data

Endpoint:

screening for reproductive / developmental toxicity

Remarks:

based on test type (migrated information)

Type of information:

migrated information: read-across based on grouping of substances (category approach)

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: see 'Remark'

Remarks:

GLP - Guideline study. According to the ECHA guidance document "Practical guide 6: How to report read-across and categories (March 2010)", the reliability was changed from RL1 to RL2 to reflect the fact that this study was conducted on a read-across substance.

Data source

Reference

Reference 1

Reference Type:

study report

Title:

Unnamed

Year:

1996

Reference 2

Reference Type:

secondary source

Title:

Dibutyl adipate CAS N°: 105-99-7

Author:

OECD

Year:

1996

Bibliographic source:

SIDS Initial Assessment Report for SIAM 4; Tokyo, Japan, 20-22 May 1996

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 421 (Reproduction / Developmental Toxicity Screening Test)

Deviations:

no

GLP compliance:

yes

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

Dibutyl adipate

EC Number:

203-350-4

EC Name:

Dibutyl adipate

Cas Number:

105-99-7

Molecular formula:

C14H26O4

IUPAC Name:

dibutyl adipate

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 Laboratories Japan, Inc., Yokohama, Japan
- Age at study initiation: 8 wks;
- Weight at study initiation: males: 270.6 - 326.5 g; females: 199.5 - 243.4 g
- Fasting period before study: No
- Diet: CA-1 by CLEA Japan, Meguro, Japan, ad libitum
- Water: tap water, ad libitum
- Acclimation period: 7 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 24 ± 1
- Humidity (%): 55 ± 5
- Air changes (per hr): 15
- Photoperiod (hrs dark / hrs light): 12/12

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

corn oil

Details on exposure:

VEHICLE
- Justification for use and choice of vehicle: due to the lipophilic properties of the test material, corn oil was selected as the appropriate vehicle
- Amount of vehicle: 5 mL/kg

Details on mating procedure:

- M/F ratio per cage: 1/1
- Length of cohabitation: up to 14 days
- Proof of pregnancy: vaginal plug and sperm in vaginal smear referred to as Day 0 of pregnancy
- After successful mating each pregnant female was caged: Individually

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

Detailed method was not described. The measured concentration was between 98.3 and 104% of nominal concentration.

Duration of treatment / exposure:

Males: 14 days before mating and for 28 days thereafter
Females: total of 42-53 days beginning 14 days before mating to day 3 of lactation

Frequency of treatment:

7 days /week

Details on study schedule:

- Age at mating of the mated animals in the study: 10 weeks

Doses / concentrations

Remarks:

Doses / Concentrations:
100, 300, 1000 mg/kg bw/day
Basis:
actual ingested

No. of animals per sex per dose:

13

Control animals:

yes, concurrent vehicle

Details on study design:

- Dose selection rationale: A dose finding study was performed. Test solutions of 0, 500 and 1000 mg/kg bw/day were administered for 14 days to female rats. Slight salivation was observed during treatment but no mortality occured. No difference in body weight and food consumption was observed and necropsy revealed no abnormalities.No change in organ weight compared with control group was observed.

Examinations

Parental animals: Observations and examinations:

CAGE SIDE OBSERVATIONS: Yes
- Time schedule: twice daily, before and after administration

BODY WEIGHT: Yes
- Time schedule for examinations: Males on Days 1, 8, 15, 22, 29, 36 and 43, females on Days 1, 8 and 15 of treatment, Days 0, 7, 14 and 20 of gestation and Days 0 and 4 of lactation

FOOD CONSUMPTION: not examined

Oestrous cyclicity (parental animals):

Observed

Sperm parameters (parental animals):

Parameters examined in parental animals:
testis weight, epididymis weight, other: histopathology

Litter observations:

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

GROSS EXAMINATION OF DEAD PUPS:
yes, for external and internal abnormalities

Postmortem examinations (parental animals):

SACRIFICE
- Male animals: All surviving animals on Day 43
- Maternal animals: All surviving animals on Day 4 of lacation

GROSS NECROPSY
- Gross necropsy consisted of external and internal examinations including the cervical, thoracic, and abdominal viscera.

HISTOPATHOLOGY / ORGAN WEIGHTS
Organ weight: kidneys and spleen of both sexes and testes and epididymides of males.
Microscopic observation: testes and epididymides of males; ovary and uterus of females

Postmortem examinations (offspring):

SACRIFICE
- The F1 offspring were sacrificed at 4 days of age.

GROSS NECROPSY
- Gross necropsy consisted of external and internal examinations.

Statistics:

Barlett's test, Dunett's test, Scheffe's test, Kruskal-Wallis test

Reproductive indices:

copulation index (no. of copulated rats/no. of mated rats x 100),
fertility index (no. of pregnant females/no. of females with successful copulation x 100),
gestation index (no. of females with live pups/no. of pregnant females x 100),
implantation index (no. of implantation sites/no. of corpora lutea x 100),
delivery index (no. of pups born/no. of implantation sited x 100)

Offspring viability indices:

birth index (no. of live pups on day 0/no. of implantation sites x 100),
live birth index (no. of live pups on Day 0/no. of pups born x 100),
viability index (no. of pups alive on Day 4 of lactation/no. of pups born x 100)

Results and discussion

Results: P0 (first parental generation)

General toxicity (P0)

Clinical signs:

effects observed, treatment-related

Description (incidence and severity):

Dose-dependent increase in number of rats with salivation after dose administration in both sexes.

Body weight and weight changes:

no effects observed

Food consumption and compound intake (if feeding study):

no effects observed

Organ weight findings including organ / body weight ratios:

effects observed, treatment-related

Histopathological findings: non-neoplastic:

no effects observed

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:

no effects observed

Details on results (P0)

CLINICAL SIGNS AND MORTALITY (PARENTAL ANIMALS)
Slight salivation was observed in treatment group with dose-responsibility (see Table 1). This change was not regarded as neurological effect but caused by stimulation by the administration of the test compound.

BODY WEIGHT AND FOOD CONSUMPTION (PARENTAL ANIMALS)
Light suppression of body weight gain was observed in males in 1000 mg/kg group but there was no significant difference.

ORGAN WEIGHTS (PARENTAL ANIMALS)
An increase in relative weight of kidney was observed in both sexes of 1000 mg/kg bw group. An increase in relative weight of spleen in males of 100 and 1000 mg/kg bw, increase in absolute weight of spleen in females of 100 mg/kg was observed ( see Table 2).

HISTOPATHOLOGY (PARENTAL ANIMALS)
Infiltration of lymphocyte in testis was observed in control and 1000 mg/kg group. This change was not related to the test compound.

OTHER FINDINGS (PARENTAL ANIMALS)
A dam in 300 mg/kg bw group didn't retrieve pups and all pups were dead until on PND 2. But this change was not regarded as compound-related effect.

Effect levels (P0)

1

Dose descriptor:

NOAEL

Remarks:

systemic

Effect level:

300 mg/kg bw/day

Based on:

test mat.

Sex:

male/female

Basis for effect level:

other: organ weights: kidney weights increased

2

Dose descriptor:

NOAEL

Remarks:

reproduction

Effect level:

>= 1 000 mg/kg bw/day

Based on:

test mat.

Sex:

male/female

Basis for effect level:

other: NOAEL for reproductive parameters is corresponding to the highest dose tested

Results: F1 generation

General toxicity (F1)

Clinical signs:

no effects observed

Mortality / viability:

mortality observed, treatment-related

Description (incidence and severity):

1000 mg/kg: Pup viability on PND 4 was decreased.

Body weight and weight changes:

effects observed, treatment-related

Description (incidence and severity):

1000 mg/kg bw: pup weight on PND 0 and 4 was slightly decreased (without reaching statistical significance)

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

Details on results (F1)

VIABILITY (OFFSPRING)
1000 mg/kg: Pup viability on PND 4 was statistically significantly decreased (see Table 3).

CLINICAL SIGNS (OFFSPRING)
No effects were observed.

BODY WEIGHT (OFFSPRING)
1000 mg/kg bw: pup weight on PND 0 and 4 was slightly decreased (without reaching statistical significance (see Table 3).

GROSS PATHOLOGY (OFFSPRING)
No effects were observed.

Effect levels (F1)

Dose descriptor:

NOAEL

Generation:

F1

Effect level:

300 mg/kg bw/day

Based on:

test mat.

Sex:

male/female

Basis for effect level:

other: pup weight; viability index

Overall reproductive toxicity

Reproductive effects observed:

not specified

Any other information on results incl. tables

Table 1: Number of animals showing salivation upon treatment [male/female]

	Dose [mg/kg bw/day]
Days of treatment	0	100	300	1000
1-7	-	-	-	12/9
18-14	-	-/1	4/4	13/13
15-21	-	3/2	7/9	13/13
22-28	-	-	2/1	12/13
29-35	-	-	6/4	13/13
36-42	-	-	6/3	13/12
43	-	-	-	-
Total	-	3/3	11/9	13/13

 

Table 2: Organ weights

Males after 42 days of treatment		Dose [mg/kg bw/day]
Kidney		0	100	300	1000
absolute weight [g]	mean	2.96	3.12	3.04	3.08
	SD	0.39	0.34	0.32	0.35
relative weight [% of mean body weight]	mean	0.6	0.61	0.63	0.65*
	SD	0.05	0.04	0.06	0.06
Spleen
absolute weight [g]	mean	0.79	0.95	0.84	0.9
	SD	0.14	0.19	0.11	0.2
relative weight [% of mean body weight]	mean	0.16	0.18*	0.17	0.19**
	SD	0.02	0.03	0.02	0.03
Females at Day 4 of lactation
Kidney
absolute weight [g]	mean	1.95	1.97	2.1	2.11
	SD	0.15	0.19	0.22	0.17
relative weight [% of mean body weight]	mean	0.6	0.58	0.62	0.65
	SD	0.04	0.03	0.05	0.07
Spleen
absolute weight (in g)	mean	0.59	0.74*	0.65	0.68
	SD	0.08	0.16	0.13	0.09
relative weight (% of mean body weight)	mean	0.18	0.22	0.19	0.21
	SD	0.03	0.04	0.03	0.03

 

Table 3: Reproductive parameters

Dose [mg/kg bw/day]		0	100	300	1000
No.of female animals:		13	13	13	13
No. of mated pairs:		13	13	13	13
No. of copulated pairs:		13	13	13	13
Copulation index [%]		100	100	100	100
No. of pregnant females		12	12	12	12
Fertility index [%]		92.3	92.3	92.3	92.3
Pairing day until copulation
	mean	4.1	2.6	3	2.7
	SD	3.3	0.8	2.3	1
Frequency of vaginal estrus
	mean	1.1	1	1.2	1
	SD	0.3	0	0.6	0
No. of pregnant females with pups alive:		12	12	12	12
Gestation index (%)		100	100	100	100
Gestation length (days)
	mean	22.3	22.1	22.2	22.2
	SD	0.5	0.3	0.4	0.4
No. of corpora lutea
	mean	15.7	15.6	17	16.9
	SD	2	1.6	1.9	1.7
No.of implantation site
	mean	14.8	14.7	15.8	15.5
	SD	2.6	2.1	3.1	2.1
Implantation index [%]
	mean	94.2	94	92.2	91.5
	SD	7.8	8.4	14.1	7.5
Day 0 of lactation
No.of pups born
	mean	13.6	14.2	15	14.6
	SD	2.4	1.9	2.9	2.3
Delivery index [%]
	mean	91.8	96.7	95.5	93.9
	SD	6.5	3.4	5.7	5.9
No.of pups alive
	mean	13.3	13.9	14.3	13.7
	SD	2.4	1.9	2.6	3.3
Birth index (%)
	mean	90.1	95.2	91.8	88.2
	SD	6.1	6	8.8	16.8
Live birth index (%)
	mean	98.2	98.4	96.2	93.6
	SD	4.6	4.1	8.4	15.2
Pups weight [g]
Male	mean	6.5	6.4	6.2	6.1
	SD	0.7	0.6	0.8	0.7
Female	mean	6.1	6	5.8	5.8
	SD	0.6	0.6	0.7	0.5
Sex ratio on day 0 of lactation [no. of male pups/total no. of pups]
	mean	47.6	41.4	49.4	48.6
	SD	13	7.7	12.7	11.9
Day 4 of lactation
No.of pups alive
	mean	13.3	13.8	13.1	13.3
	SD	2.4	1.7	4.8	3.5
Viability index [%]
	mean	100	99.5	90.6	96.1*
	SD	0	1.7	28.6	5.3
Pups weight [g] on day 4 of lactation
Male	mean	10.6	10.8	10.2	9.9
	SD	1.8	1.2	1.7	1.9
Female	mean	10.1	10.1	9.7	9.3
	SD	1.7	1.2	1.6	1.4

SD standard deviation

* significant difference from control, p<0.05

** significant difference from control, p<0.01