Phenethyl acetate

Developmental toxicity / teratogenicity

Administrative data

Endpoint:

developmental toxicity

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

key study

Study period:

published in 1993

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Published literature study

Justification for type of information:

Based on structural, physicochemical and toxicity data, similarities between benzyl acetate is considered appropriate for use of the information by read across to phenyl ethyl acetate - see review attached in IUCLID section 13.2.

Cross-reference

Reason / purpose for cross-reference:

read-across source

Reference

Endpoint:

developmental toxicity

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

key study

Study period:

published in 1993

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Published literature study

Justification for type of information:

Based on structural, physicochemical and toxicity data, similarities between benzyl acetate is considered appropriate for use of the information by read across to phenyl ethyl acetate - see review attached in IUCLID section 13.2.

Reason / purpose for cross-reference:

read-across source

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 414 (Prenatal Developmental Toxicity Study)

GLP compliance:

not specified

Limit test:

no

Species:

rat

Strain:

Wistar

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Keari Inc.
- Age at study initiation: Females: 10 to 15 weeks
Males: 12 to 17 weeks.
- Weight at study initiation: Not documented
- Fasting period before study: Not documented
- Housing: Not documented
- Diet (e.g. ad libitum): Solid food purchased form Japan Kurea
- Water (e.g. ad libitum): Tap water
- Acclimation period: 2 weeks

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22 ± 1°C
- Humidity (%): 50 ± 10%
- Air changes (per hr): Not documented
- Photoperiod (hrs dark / hrs light): 12 hours light/dark

IN-LIFE DATES: From: To: Not documented

Route of administration:

oral: gavage

Vehicle:

olive oil

Details on exposure:

PREPARATION OF DOSING SOLUTIONS:
The test susbtance, benzyl acetate, was mixed with olive oil to achieve concentration levels of 1000, 500, 100, 10 and 0 mg/ml

VEHICLE
- Justification for use and choice of vehicle (if other than water): olive oil
- Concentration in vehicle: Not documented
- Amount of vehicle (if gavage): Not documented
- Lot/batch no. (if required): VDR7446
- Purity: Not documented

Analytical verification of doses or concentrations:

not specified

Details on analytical verification of doses or concentrations:

No information provided

Details on mating procedure:

On confirmation of the oestrous cycle of the females, 12-17 week old male rats were introduced and the males and females were co-housed from 5pm until the next morning when the presence of sperm in the vagina was considered to be successful mating. This was considered to be day zero of pregnancy. Based on their weight, pregnant rats were separated into 6 groups and relocated to separate cages.

Duration of treatment / exposure:

10 days

Frequency of treatment:

Once each day from days 6 to 15 of gestation

Duration of test:

Animals terminated on Day 20 of gestation

Remarks:

Doses / Concentrations:
0, 10, 100, 500, 1000 mg/kg bw/d
Basis:
actual ingested

No. of animals per sex per dose:

20-22 mated females per group

Control animals:

yes, concurrent no treatment

Details on study design:

- Dose selection rationale: No information
- Rationale for animal assignment (if not random): random
- Other: no other information

Maternal examinations:

CAGE SIDE OBSERVATIONS: Yes
- Time schedule: Daily

DETAILED CLINICAL OBSERVATIONS: No data

BODY WEIGHT: Yes
- Time schedule for examinations: Every 2 days

FOOD CONSUMPTION AND COMPOUND INTAKE (if feeding study): Yes
Examined every 2 days.

WATER CONSUMPTION AND COMPOUND INTAKE (if drinking water study): No data

POST-MORTEM EXAMINATIONS: Yes
- Sacrifice on gestation day # 20
- Organs examined: Not documented

OTHER: The implantation in the womb, corpus lutea quantity, the implantation quantity, the resorption embryo count and the living or dead foetuses. The weight of the placenta was measured.

Ovaries and uterine content:

Examinations included:
- Gravid uterus weight: No data
- Number of corpora lutea: Yes
- Number of implantations: Yes
- Number of early resorptions: No data
- Number of late resorptions: No data

Fetal examinations:

- External examinations: Yes: all living foetuses
- Soft tissue examinations: Yes: half per litter
- Skeletal examinations: Yes:
- Head examinations: No data

Statistics:

One way layout dispersion method if equal dispersion detected. The Kruskal-Wallis method was used to verify significance in the case of equal dispersion. The multi-comparison verification method of Scheffe and Dunnett was used to verify the significance of subjected groups. An X2 verification method was also performed to determine the frequency of of the bone changes, internal organs of the foetuses and the gender comparison of the surviving foetuses.

Indices:

Not documented

Historical control data:

No information provided

Details on maternal toxic effects:

Maternal toxic effects:yes

Details on maternal toxic effects:
There were no specific changes observed in the general condition or behaviour of the animals throughout the course of the study. No mortalities were observed in any treatment group. There were no significant differences in body weight observed between treatment groups. However, there was a tendency for the body weight to decrease in 1000mg/kg dose group from day 16 to day 20 of test substance administration and during the course of the pregnancy to day 20. A slight effect was also apparent at 500 mg/kg bw/d. There were no significant changes in food consumption in any of the treatment groups from the start to the end of pregnancy. On gross examination, there were no visible abnormalities in the internal organs examined

Dose descriptor:

NOAEL

Effect level:

500 mg/kg bw/day

Based on:

test mat.

Basis for effect level:

other: maternal toxicity

Dose descriptor:

NOAEL

Effect level:

500 mg/kg bw/day

Based on:

test mat.

Basis for effect level:

other: developmental toxicity

Details on embryotoxic / teratogenic effects:

Embryotoxic / teratogenic effects:no effects

Details on embryotoxic / teratogenic effects:
Numbers of corpora lutea were comparable in all groups; the numbers of implantations and live foetuses were marginally lower at 1000 mg/kg bw/d. A single dead foetus was observed at 1000 mg/kg bw/d. Resorptions were comparable in al groups. Mean male foetal weight was marginally but significantly higher at 10 and 100 mg/kg bw/d; mean male and female foetal weights were significantly lower at 1000 mg/kg bw/d.

No external or visceral malformations were observed in any group. The number of visceral variations was significantly higher at 500 and 1000 mg/kg bw/d; increased incidences of ventricular dilation and renal pelvis dilation indicate an effect of treatment at 1000 mg/kg bw/d but not at 500 mg/kg bw/d. A single skeletal malformation (fused rib) was seen at 1000 mg/kg bw/d but is not considered to be clearly related to treatment. The incidence of skeletal variations was significantly increased at 1000 mg/kg bw/d; incidences of wavy rib, lumbar rib and other parameters indicative of reduced ossification were increased at this dose level.

Remarks on result:

other: Not specified

Abnormalities:

not specified

Developmental effects observed:

not specified

Maternal findings

Group	Untreated controls	Vehicle controls	10 mg/kg bw/d	100 mg/kg bw/d	500 mg/kg bw/d	1000 mg/kg bw/d
N	20	20	21	21	20	22
Overall maternal weight gain (g) D0 -20	157.6	160.7	159.0	166.3	151.3	149.1
Weight gain (g) D16 -20	65.4	66.4	64.5	67.2	60.9	56.8

Litter parameters

Group	Untreated controls	Vehicle controls	10 mg/kg bw/d	100 mg/kg bw/d	500 mg/kg bw/d	1000 mg/kg bw/d
Corpora lutea (#)	17.1	18.1	18.2	17.2	17.7	17.4
Implantations (#)	15.5	15.2	15.2	15.7	15.6	14.6
Live foetuses (#)	15.0	14.5	14.7	15.1	14.6	13.9
Dead foetuses (total)	0	0	0	0	0	1
Resorptions (#)	0.6	0.7	0.6	0.5	1.0	0.7
Foetal weight M (g)	4.09	3.91	4.21*	4.12*	4.05	3.35*
Foetal weight F (g)	3.92	3.85	3.97	3.89	3.85	3.17*

Foetal parameters

Group	Untreated controls	Vehicle controls	10 mg/kg bw/d	100 mg/kg bw/d	500 mg/kg bw/d	1000 mg/kg bw/d
External malformations (#)	-	-	-	-	-	-
Visceral malformations (#)	-	-	-	-	-	-
Visceral variations (#)	3(2)	5 (2)	9 (4)	3 (2)	14 (4)*	17 (10)*
Ventricular dilation (#)	2 (1)	3 (2)	8 (3)	2 (1)	7 (3)	11 (6)*
Levo-umbilical artery (#)	-	-	2 (1)	-	-	2 (2)
Renal pelvis dilation (#)	1 (1)	3 (2)	8 (3)	2 (1)	7 (3)	11 (6)*
Skeletal malformations (#)	-	-	-	-	-	1 (1)
Fused ribs (#)	-	-	-	-	-	1 (1)
Skeletal variations (#)	8 (5)	29 (12)	16 (11)	24 (10)	22 (11)	73 (21)*
Wavy ribs	1 (1)	6 (4)	4 (3)	5 (3)	11 (5)	21 (12)*
Dumbbell thoracic vertebra	-	-	-	-	-	6 (3)*
Absent thoracic vertebral body	-	-	-	-	-	10 (4)
Split thoracic vertebral body	-	1 (1)	1 (1)	-	-	6 (3)*
Lumbar ribs	8 (5)	23 (10)	12 (8)	19 (8)	10 (7)	48 (17)*
Absent lumbar vertebral body	-	1 (1)	1 (1)	-	1 (1)	4 (4)
Dumbbell lumbar vertebra	-	-	-	-	-	1 (1)
Ossification: cervical vertebrae	3.36	3.44	3.44	3.24	2.72	0.78*
Ossification: caudal vertebrae	4.33	4.15	4.32	4.19	3.87	3.24*
Sternebrae	5.77	5.69	5.77	5.63	5.37	4.14*

Conclusions:

Maternal and developmental NOAELs of 500 mg/kg bw/d are derived for this study.

Executive summary:

In a guideline-comparable developmental toxicity study, mated female Wistar rats (20 -22/group) were gavaged with benzyl acetate at dose levels of 10, 100, 500 or 1000 mg/kg bw/d on days 6 -15 of gestation. Additional groups were administered the vehicle alone or were untreated. Animals were terminated on Day 20 of gestation and the uterine contents examined: foetuses were assessed for external, visceral and skeletal findings.

A tendency to reduced weight gain was seen in females at 1000 mg/kg bw/d and to a lesser extent at 500 mg/kg bw/d. Numbers of corpora lutea were comparable in all groups; the numbers of implantations and live foetuses were marginally lower at 1000 mg/kg bw/d. A single dead foetus was observed at 1000 mg/kg bw/d. Resorptions were comparable in al groups. Mean male foetal weight was marginally but significantly higher at 10 and 100 mg/kg bw/d; mean male and female foetal weights were significantly lower at 1000 mg/kg bw/d. No external or visceral malformations were observed in any group. The number of visceral variations was significantly higher at 500 and 1000 mg/kg bw/d; increased incidences of ventricular dilation and renal pelvis dilation indicate an effect of treatment at 1000 mg/kg bw/d but not at 500 mg/kg bw/d. A single skeletal malformation (fused rib) was seen at 1000 mg/kg bw/d but is not considered to be clearly related to treatment. The incidence of skeletal variations was significantly increased at 1000 mg/kg bw/d; incidences of wavy rib, lumbar rib and other parameters indicative of reduced ossification were increased at this dose level.

Maternal and developmental toxicity was observed in this study at the highest dose level of 1000 mg/kg bw/d. Maternal and developmental NOAELs of 500 mg/kg bw/d are therefore derived.

Data source

Reference

Reference Type:

publication

Title:

Teratological Studies on Benzyl Acetate in Pregnant Rats.

Author:

Ishiguro, S., Miyamoto, A., Obi, T and Nishio, A.

Year:

1993

Bibliographic source:

Kagoshima University Agricultural Academic Report, No 43, p. 25-31, 1993

Report date:

1993

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 414 (Prenatal Developmental Toxicity Study)

GLP compliance:

not specified

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

Benzyl acetate

EC Number:

205-399-7

EC Name:

Benzyl acetate

Cas Number:

140-11-4

Molecular formula:

C9H10O2

IUPAC Name:

benzyl acetate

Test animals

Species:

rat

Strain:

Wistar

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Keari Inc.
- Age at study initiation: Females: 10 to 15 weeks
Males: 12 to 17 weeks.
- Weight at study initiation: Not documented
- Fasting period before study: Not documented
- Housing: Not documented
- Diet (e.g. ad libitum): Solid food purchased form Japan Kurea
- Water (e.g. ad libitum): Tap water
- Acclimation period: 2 weeks

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22 ± 1°C
- Humidity (%): 50 ± 10%
- Air changes (per hr): Not documented
- Photoperiod (hrs dark / hrs light): 12 hours light/dark

IN-LIFE DATES: From: To: Not documented

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

olive oil

Details on exposure:

PREPARATION OF DOSING SOLUTIONS:
The test susbtance, benzyl acetate, was mixed with olive oil to achieve concentration levels of 1000, 500, 100, 10 and 0 mg/ml

VEHICLE
- Justification for use and choice of vehicle (if other than water): olive oil
- Concentration in vehicle: Not documented
- Amount of vehicle (if gavage): Not documented
- Lot/batch no. (if required): VDR7446
- Purity: Not documented

Analytical verification of doses or concentrations:

not specified

Details on analytical verification of doses or concentrations:

No information provided

Details on mating procedure:

On confirmation of the oestrous cycle of the females, 12-17 week old male rats were introduced and the males and females were co-housed from 5pm until the next morning when the presence of sperm in the vagina was considered to be successful mating. This was considered to be day zero of pregnancy. Based on their weight, pregnant rats were separated into 6 groups and relocated to separate cages.

Duration of treatment / exposure:

10 days

Frequency of treatment:

Once each day from days 6 to 15 of gestation

Duration of test:

Animals terminated on Day 20 of gestation

Doses / concentrations

Remarks:

Doses / Concentrations:
0, 10, 100, 500, 1000 mg/kg bw/d
Basis:
actual ingested

No. of animals per sex per dose:

20-22 mated females per group

Control animals:

yes, concurrent no treatment

Details on study design:

- Dose selection rationale: No information
- Rationale for animal assignment (if not random): random
- Other: no other information

Examinations

Maternal examinations:

CAGE SIDE OBSERVATIONS: Yes
- Time schedule: Daily

DETAILED CLINICAL OBSERVATIONS: No data

BODY WEIGHT: Yes
- Time schedule for examinations: Every 2 days

FOOD CONSUMPTION AND COMPOUND INTAKE (if feeding study): Yes
Examined every 2 days.

WATER CONSUMPTION AND COMPOUND INTAKE (if drinking water study): No data

POST-MORTEM EXAMINATIONS: Yes
- Sacrifice on gestation day # 20
- Organs examined: Not documented

OTHER: The implantation in the womb, corpus lutea quantity, the implantation quantity, the resorption embryo count and the living or dead foetuses. The weight of the placenta was measured.

Ovaries and uterine content:

Examinations included:
- Gravid uterus weight: No data
- Number of corpora lutea: Yes
- Number of implantations: Yes
- Number of early resorptions: No data
- Number of late resorptions: No data

Fetal examinations:

- External examinations: Yes: all living foetuses
- Soft tissue examinations: Yes: half per litter
- Skeletal examinations: Yes:
- Head examinations: No data

Statistics:

One way layout dispersion method if equal dispersion detected. The Kruskal-Wallis method was used to verify significance in the case of equal dispersion. The multi-comparison verification method of Scheffe and Dunnett was used to verify the significance of subjected groups. An X2 verification method was also performed to determine the frequency of of the bone changes, internal organs of the foetuses and the gender comparison of the surviving foetuses.

Indices:

Not documented

Historical control data:

No information provided

Results and discussion

Results: maternal animals

Maternal developmental toxicity

Details on maternal toxic effects:

Maternal toxic effects:yes

Details on maternal toxic effects:
There were no specific changes observed in the general condition or behaviour of the animals throughout the course of the study. No mortalities were observed in any treatment group. There were no significant differences in body weight observed between treatment groups. However, there was a tendency for the body weight to decrease in 1000mg/kg dose group from day 16 to day 20 of test substance administration and during the course of the pregnancy to day 20. A slight effect was also apparent at 500 mg/kg bw/d. There were no significant changes in food consumption in any of the treatment groups from the start to the end of pregnancy. On gross examination, there were no visible abnormalities in the internal organs examined

Effect levels (maternal animals)

1

Dose descriptor:

NOAEL

Effect level:

500 mg/kg bw/day

Based on:

test mat.

Basis for effect level:

other: maternal toxicity

2

Dose descriptor:

NOAEL

Effect level:

500 mg/kg bw/day

Based on:

test mat.

Basis for effect level:

other: developmental toxicity

Results (fetuses)

Details on embryotoxic / teratogenic effects:

Embryotoxic / teratogenic effects:no effects

Details on embryotoxic / teratogenic effects:
Numbers of corpora lutea were comparable in all groups; the numbers of implantations and live foetuses were marginally lower at 1000 mg/kg bw/d. A single dead foetus was observed at 1000 mg/kg bw/d. Resorptions were comparable in al groups. Mean male foetal weight was marginally but significantly higher at 10 and 100 mg/kg bw/d; mean male and female foetal weights were significantly lower at 1000 mg/kg bw/d.

No external or visceral malformations were observed in any group. The number of visceral variations was significantly higher at 500 and 1000 mg/kg bw/d; increased incidences of ventricular dilation and renal pelvis dilation indicate an effect of treatment at 1000 mg/kg bw/d but not at 500 mg/kg bw/d. A single skeletal malformation (fused rib) was seen at 1000 mg/kg bw/d but is not considered to be clearly related to treatment. The incidence of skeletal variations was significantly increased at 1000 mg/kg bw/d; incidences of wavy rib, lumbar rib and other parameters indicative of reduced ossification were increased at this dose level.

Effect levels (fetuses)

Remarks on result:

other: Not specified

Fetal abnormalities

Abnormalities:

not specified

Overall developmental toxicity

Developmental effects observed:

not specified

Any other information on results incl. tables

Maternal findings

Group	Untreated controls	Vehicle controls	10 mg/kg bw/d	100 mg/kg bw/d	500 mg/kg bw/d	1000 mg/kg bw/d
N	20	20	21	21	20	22
Overall maternal weight gain (g) D0 -20	157.6	160.7	159.0	166.3	151.3	149.1
Weight gain (g) D16 -20	65.4	66.4	64.5	67.2	60.9	56.8

Litter parameters

Group	Untreated controls	Vehicle controls	10 mg/kg bw/d	100 mg/kg bw/d	500 mg/kg bw/d	1000 mg/kg bw/d
Corpora lutea (#)	17.1	18.1	18.2	17.2	17.7	17.4
Implantations (#)	15.5	15.2	15.2	15.7	15.6	14.6
Live foetuses (#)	15.0	14.5	14.7	15.1	14.6	13.9
Dead foetuses (total)	0	0	0	0	0	1
Resorptions (#)	0.6	0.7	0.6	0.5	1.0	0.7
Foetal weight M (g)	4.09	3.91	4.21*	4.12*	4.05	3.35*
Foetal weight F (g)	3.92	3.85	3.97	3.89	3.85	3.17*

Foetal parameters

Group	Untreated controls	Vehicle controls	10 mg/kg bw/d	100 mg/kg bw/d	500 mg/kg bw/d	1000 mg/kg bw/d
External malformations (#)	-	-	-	-	-	-
Visceral malformations (#)	-	-	-	-	-	-
Visceral variations (#)	3(2)	5 (2)	9 (4)	3 (2)	14 (4)*	17 (10)*
Ventricular dilation (#)	2 (1)	3 (2)	8 (3)	2 (1)	7 (3)	11 (6)*
Levo-umbilical artery (#)	-	-	2 (1)	-	-	2 (2)
Renal pelvis dilation (#)	1 (1)	3 (2)	8 (3)	2 (1)	7 (3)	11 (6)*
Skeletal malformations (#)	-	-	-	-	-	1 (1)
Fused ribs (#)	-	-	-	-	-	1 (1)
Skeletal variations (#)	8 (5)	29 (12)	16 (11)	24 (10)	22 (11)	73 (21)*
Wavy ribs	1 (1)	6 (4)	4 (3)	5 (3)	11 (5)	21 (12)*
Dumbbell thoracic vertebra	-	-	-	-	-	6 (3)*
Absent thoracic vertebral body	-	-	-	-	-	10 (4)
Split thoracic vertebral body	-	1 (1)	1 (1)	-	-	6 (3)*
Lumbar ribs	8 (5)	23 (10)	12 (8)	19 (8)	10 (7)	48 (17)*
Absent lumbar vertebral body	-	1 (1)	1 (1)	-	1 (1)	4 (4)
Dumbbell lumbar vertebra	-	-	-	-	-	1 (1)
Ossification: cervical vertebrae	3.36	3.44	3.44	3.24	2.72	0.78*
Ossification: caudal vertebrae	4.33	4.15	4.32	4.19	3.87	3.24*
Sternebrae	5.77	5.69	5.77	5.63	5.37	4.14*

Applicant's summary and conclusion

Conclusions:

Maternal and developmental NOAELs of 500 mg/kg bw/d are derived for this study.

Executive summary:

In a guideline-comparable developmental toxicity study, mated female Wistar rats (20 -22/group) were gavaged with benzyl acetate at dose levels of 10, 100, 500 or 1000 mg/kg bw/d on days 6 -15 of gestation. Additional groups were administered the vehicle alone or were untreated. Animals were terminated on Day 20 of gestation and the uterine contents examined: foetuses were assessed for external, visceral and skeletal findings.

A tendency to reduced weight gain was seen in females at 1000 mg/kg bw/d and to a lesser extent at 500 mg/kg bw/d. Numbers of corpora lutea were comparable in all groups; the numbers of implantations and live foetuses were marginally lower at 1000 mg/kg bw/d. A single dead foetus was observed at 1000 mg/kg bw/d. Resorptions were comparable in al groups. Mean male foetal weight was marginally but significantly higher at 10 and 100 mg/kg bw/d; mean male and female foetal weights were significantly lower at 1000 mg/kg bw/d. No external or visceral malformations were observed in any group. The number of visceral variations was significantly higher at 500 and 1000 mg/kg bw/d; increased incidences of ventricular dilation and renal pelvis dilation indicate an effect of treatment at 1000 mg/kg bw/d but not at 500 mg/kg bw/d. A single skeletal malformation (fused rib) was seen at 1000 mg/kg bw/d but is not considered to be clearly related to treatment. The incidence of skeletal variations was significantly increased at 1000 mg/kg bw/d; incidences of wavy rib, lumbar rib and other parameters indicative of reduced ossification were increased at this dose level.

Maternal and developmental toxicity was observed in this study at the highest dose level of 1000 mg/kg bw/d. Maternal and developmental NOAELs of 500 mg/kg bw/d are therefore derived.