Benzyl acetate

Developmental toxicity / teratogenicity

Administrative data

Endpoint:

developmental toxicity

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1972

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1972

Report date:

1972

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 414 (Prenatal Developmental Toxicity Study)

Principles of method if other than guideline:

Females artifically inseminated with 0.3 mL of diluted semen from a proven donor buck using approximatley 20 x 10^6 motile sperm according to the procedure described by Vogin et al (Pharmacologist 11, 282 (1969). The females were dosed by oral gavage on Day 6 to 18 of gestation. Body weights were recorded on Days 0, 6, 12, 18 and 29 of gestation. All animals were observed daily for appearance and behaviour, including food consumption and body weight. Numbers of corpora lutea, implantation sites and resorption sites were recorded. The numbers of live and dead foetuses were recorded. Body weights of the live pups were recorded. The urogenital tract of each animal was examined in detail for normality. All foetuses underwent a detailed gross examination for the presence of external congenital abnormalities. The live foetuses were placed in an incubator for 24 hours for the evaluation of neonatal survival. All surviving pups were sacrificed and all pups were examined for visceral abnormalities by dissection. All foetuses were then cleared in potassium hydroxide, stained with alizarin red S dye and examined for skeletal defects.

GLP compliance:

no

Test material

Test material information

Constituent 1

Reference substance name:

Reference substance 001

Cas Number:

532-32-1

Specific details on test material used for the study:

Sodium benzoate

Test animals

Species:

rabbit

Strain:

other: Dutch-belted

Details on test animals or test system and environmental conditions:

Housed individually in mesh bottom cages
Temperature and humidity controlled
Food and fresh tap water ad libitum

Administration / exposure

Route of administration:

oral: gavage

Details on exposure:

Females were dosed by oral gavage on Day 6 to 18 of gestation.

Analytical verification of doses or concentrations:

no

Details on mating procedure:

Females artifically inseminated with 0.3 mL of diluted semen from a proven donor buck using approximatley 20 x 10^6 motile sperm according to the procedure described by Vogin et al (Pharmacologist 11, 282 (1969).

Duration of treatment / exposure:

Days 6 to 18 of gestation.

Frequency of treatment:

Daily

Duration of test:

29 days

Doses / concentrations

Doses / concentrations 1

Dose / conc.:

0 mg/kg bw/day (nominal)

Remarks:

Sham exposed controls

Doses / concentrations 2

Dose / conc.:

2.5 mg/kg bw/day (nominal)

Doses / concentrations 3

Dose / conc.:

12 mg/kg bw/day (nominal)

Doses / concentrations 4

Dose / conc.:

54 mg/kg bw/day (nominal)

Doses / concentrations 5

Dose / conc.:

250 mg/kg bw/day (nominal)

No. of animals per sex per dose:

Sham treatment: 17 females mated
Positive control: 15 females mated
2.5 mg/kg bw/day: 32 females mated
12.0 mg/kg bw/day: 21 females mated
54 mg/kg bw/day: 22 females mated
250 mg.kg bw/day: 14 females mated

Control animals:

yes, sham-exposed

other:

Details on study design:

All does were subjected to Caesarean section under surgical anaesthesia on Day 29 of gestation.

Examinations

Maternal examinations:

Body weights were recorded on Days 0, 6, 12, 18 and 29 of gestation. All animals were observed daily for appearance and behaviour, including food consumption and body weight.

Ovaries and uterine content:

Numbers of corpora lutea, implantation sites and resorption sites were recorded.

Fetal examinations:

The numbers of live and dead foetuses were recorded. Body weights of the live pups were recorded. The urogenital tract of each animal was examined in detail for normality. All foetuses underwent a detailed gross examination for the presence of external congenital abnormalities. The live foetuses were placed in an incubator for 24 hours for the evaluation of neonatal survival. All surviving pups were sacrificed and all pups were examined for visceral abnormalities by dissection. All foetuses were then cleared in potassium hydroxide, stained with alizarin red S dye and examined for skeletal defects.

Results and discussion

Results: maternal animals

General toxicity (maternal animals)

Clinical signs:

effects observed, treatment-related

Dermal irritation (if dermal study):

not examined

Mortality:

mortality observed, treatment-related

Body weight and weight changes:

no effects observed

Food consumption and compound intake (if feeding study):

not examined

Food efficiency:

not examined

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

not examined

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:

not examined

Neuropathological findings:

not examined

Histopathological findings: non-neoplastic:

not examined

Histopathological findings: neoplastic:

not examined

Other effects:

not examined

Maternal developmental toxicity

Number of abortions:

no effects observed

Pre- and post-implantation loss:

no effects observed

Total litter losses by resorption:

no effects observed

Early or late resorptions:

no effects observed

Dead fetuses:

no effects observed

Changes in pregnancy duration:

not examined

Description (incidence and severity):

Migrated Data from removed field(s)
Field "Effects on pregnancy duration" (Path: ENDPOINT_STUDY_RECORD.DevelopmentalToxicityTeratogenicity.ResultsAndDiscussion.ResultsMaternalAnimals.MaternalDevelopmentalToxicity.EffectsOnPregnancyDuration): not examined

Changes in number of pregnant:

no effects observed

Other effects:

no effects observed

Effect levels (maternal animals)

Key result

Remarks on result:

not determinable due to adverse toxic effects at highest dose / concentration tested

Results (fetuses)

Fetal body weight changes:

no effects observed

Description (incidence and severity):

Migrated Data from removed field(s)
Field "Fetal/pup body weight changes" (Path: ENDPOINT_STUDY_RECORD.DevelopmentalToxicityTeratogenicity.ResultsAndDiscussion.ResultsFetuses.FetalPupBodyWeightChanges): not examined

Reduction in number of live offspring:

no effects observed

Changes in sex ratio:

no effects observed

Changes in litter size and weights:

no effects observed

Changes in postnatal survival:

not specified

External malformations:

no effects observed

Skeletal malformations:

no effects observed

Visceral malformations:

no effects observed

Other effects:

not specified

Effect levels (fetuses)

Key result

Dose descriptor:

NOAEL

Effect level:

250 mg/kg bw/day

Based on:

test mat.

Sex:

female

Remarks on result:

not determinable due to absence of adverse toxic effects

Fetal abnormalities

Key result

Abnormalities:

no effects observed

Overall developmental toxicity

Key result

Developmental effects observed:

no

Any other information on results incl. tables

Fate of doe rabbits

	Sham 0 mg/kg bw/day	2.5 mg/kg bw/day	12.0 mg/kg bw/day	54.0 mg/kg bw/day	250 mg/kg bw/day	Positive control
Total mated	17	32	21	22	14	15
Total pregnant	10	12	10	12	10	10
Total surviving at term	16	28	21	20	12	15
Pregnant surviving at term	10	10	10	11	9	10

 

Maternal body weight (g)

	Sham 0 mg/kg bw/day	2.5 mg/kg bw/day	12.0 mg/kg bw/day	54.0 mg/kg bw/day	250 mg/kg bw/day	Positive control
Day 0	2.69	2.25	2.30	2.53	2.62	2.78
Day 6	2.45	2.29	2.37	2.63	2.74	2.86
Day 12	2.82	2.31	2.32	2.63	2.73	-
Day 18	2.87	2.37	2.34	2.60	2.76	-
Day 29	2.90 (10)	2.47 (10)	2.38 (10)	2.64 (11)	2.86 (9)	2.95 (10)

Number of surviving dams in parenthesis

Litter data

	Sham 0 mg/kg bw/day	2.5 mg/kg bw/day	12.0 mg/kg bw/day	54.0 mg/kg bw/day	250 mg/kg bw/day	Positive control
Total pregnancies	10	12	10	12	10	10
Died or aborted before Day 29	1	4	0	2	2	0
To term pregnancies (on Day 29)	10	10	10	11	9	10
Total corpora lutea	170	302	204	217	207	185
Mean corpora lutea/dam mated	10.0	9.44	9.71	9.86	14.8	12.3
Number of live litters	9	10	8	5	8	7
Total implant sites	59	54	55	51	65	71
Mean implant sites/dam	5.90	5.40	5.50	4.64	7.22	7.10
Total number of resorptions	6	14	13	36	12	39
Dams with 1 or more sites resorbed	3	6	4	11	5	9
Dams with all sites resorbed	1	-	1	6	1	3
Percent partial resorption	30.0	60.0	40.0	100.0	55.6	90.0
Percent complete resorption	10.0	-	10.0	54.6	11.1	30.0
Live foetuses	52	39	36	15	53	30
Average/dam	5.20	3.90	3.60	1.36	5.89	3.00
Sex ratio (M/F)	0.73	1.44	0.89	0.50	0.77	0.85
Dead foetuses	1	1	6	-	-	2
Dams with 1 or more dead foetus	1	1	1	-	-	2
Dams with all dead foetuses	-	-	1	-	-	-
Percent partial dead foetuses	10.0	10.0	10.0	-	-	20.0
Percent all dead foetuses	-	-	10.0	-	-	-
Average foetus weight (g)	38.0	35.4	36.3	41.9	38.6	32.4

Skeletal findings

	Sham 0 mg/kg bw/day	2.5 mg/kg bw/day	12.0 mg/kg bw/day	54.0 mg/kg bw/day	250 mg/kg bw/day	Positive control
Live foetuses examined at term	50/9	39/10	36/8	15/5	53/8	26/7
Incomplete oscillation of sternebrae		1/1	1/1			6/4
Bipartite sternebrae			1/1			1/1
Fused sternebrae		2/2		1/1		8/4
Extra sternebrae	2/2	2/2	1/1		3/2	2/1
Fused or split ribs						7/4
Scrambled vertebrae						10/5
Scoliosis of vertebrae						3/2
Tail defects						26/7
Craniostosis			1/1			2/1

Data presented as number of foetuses affected/number of litters affected

Applicant's summary and conclusion

Conclusions:

No evidence of maternal or developmental toxicity was seen in this study.

Executive summary:

The administration of up to 250 mg/kg bw/d of sodium benzoate to pregnant rabbits for 13 consecutive days (from Day 6 to 18 of gestation) had no clearly discernible effect on nidation or on maternal or foetal survival. The number of abnormalities seen in either soft or skeletal tissues of the test groups did not differ from the number occurring spontaneously in the sham-treated controls.