Methyl benzoate

Repeated dose toxicity: oral

Administrative data

Endpoint:

chronic toxicity: oral

Type of information:

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

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: very concise study summary is available

Data source

Reference

Reference Type:

publication

Title:

Die Verträglichkeit der Benzoesäure in chronischen Fütterungsversuch

Author:

Kieckebusch W, Lang K

Year:

1960

Bibliographic source:

Arzneimittel Forschung 10, 1001-1003

Materials and methods

Test guideline

Qualifier:

no guideline followed

Principles of method if other than guideline:

4-generation study

GLP compliance:

no

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

Benzoic acid

EC Number:

200-618-2

EC Name:

Benzoic acid

Cas Number:

65-85-0

Molecular formula:

C7H6O2

IUPAC Name:

Benzoic acid

Details on test material:

- Name of test material (as cited in study report): Benzoesäure

Test animals

Species:

rat

Strain:

not specified

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Farbwerke Bayer (Elberfeld)
- Age at study initiation: no data
- Weight at study initiation: 40-50 g
- Fasting period before study: no data
- Housing: no data
- Diet (e.g. ad libitum): first 8 weeks "paired feed" technique was applied and after ad libitum
- Water (e.g. ad libitum): ad libitum
- Acclimation period: no data

ENVIRONMENTAL CONDITIONS
- Temperature (°C): no data
- Humidity (%): no data
- Air changes (per hr): no data
- Photoperiod (hrs dark / hrs light): no data

Administration / exposure

Route of administration:

oral: feed

Vehicle:

unchanged (no vehicle)

Details on oral exposure:

PREPARATION OF DOSING SOLUTIONS:

DIET PREPARATION
- Rate of preparation of diet (frequency): no data
- Mixing appropriate amounts with (Type of food): no data
- Storage temperature of food: no data

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

every 6 weeks

Duration of treatment / exposure:

Generation 1 and 2: lifelong; generation 3: 16 weeks; generation 4: until breeding

Frequency of treatment:

in 8 first weeks a "paired feed" technique was applied and after ad libitum

Doses / concentrations

Remarks:

Doses / Concentrations:
0, 0.5, 1 %
Basis:
nominal in diet

No. of animals per sex per dose:

20

Control animals:

yes, plain diet

Details on study design:

- Dose selection rationale: no data
- Rationale for animal assignment (if not random): no data
- Section schedule rationale (if not random): no data

Examinations

Observations and examinations performed and frequency:

CAGE SIDE OBSERVATIONS: No data

DETAILED CLINICAL OBSERVATIONS: No data

BODY WEIGHT: Yes
- Time schedule for examinations: in the first 8 weeks body weight was measured weekly and later in four week interval

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: No data
- Compound intake calculated as time-weighted averages from the consumption and body weight gain data: yes

FOOD EFFICIENCY:
- Body weight gain in kg/food consumption in kg per unit time X 100 calculated as time-weighted averages from the consumption and body weight gain data: No data

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

OPHTHALMOSCOPIC EXAMINATION: No data

HAEMATOLOGY: No data

CLINICAL CHEMISTRY: No data

URINALYSIS: No data

NEUROBEHAVIOURAL EXAMINATION: No data

Sacrifice and pathology:

GROSS PATHOLOGY: Yes (3rd generation)
HISTOPATHOLOGY: Yes (3rd generation)

Results and discussion

Results of examinations

Clinical signs:

not specified

Mortality:

not specified

Body weight and weight changes:

no effects observed

Food consumption and compound intake (if feeding study):

no effects observed

Food efficiency:

not specified

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

not specified

Ophthalmological findings:

not specified

Haematological findings:

not specified

Clinical biochemistry findings:

not specified

Urinalysis findings:

not specified

Behaviour (functional findings):

not specified

Organ weight findings including organ / body weight ratios:

effects observed, treatment-related

Description (incidence and severity):

liver weight increase in females caused by weight increase during lactation and variation in litter size (3rd generation)

Gross pathological findings:

no effects observed

Histopathological findings: non-neoplastic:

no effects observed

Histopathological findings: neoplastic:

not specified

Details on results:

CLINICAL SIGNS AND MORTALITY
no data

BODY WEIGHT AND WEIGHT GAIN
no effects

FOOD CONSUMPTION AND COMPOUND INTAKE (if feeding study)
no effects

FOOD EFFICIENCY
no data

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

OPHTHALMOSCOPIC EXAMINATION
no data

HAEMATOLOGY
no data

CLINICAL CHEMISTRY
no data

URINALYSIS
no data

NEUROBEHAVIOUR
no data

ORGAN WEIGHTS
liver weight increase in females caused by weight increase during lactation and variation in liter size (3rd generation)

GROSS PATHOLOGY
no effects

HISTOPATHOLOGY: NON-NEOPLASTIC
no effects

HISTOPATHOLOGY: NEOPLASTIC (if applicable)
no data

HISTORICAL CONTROL DATA (if applicable)
no data

Effect levels

1

Dose descriptor:

NOEL

Effect level:

500 mg/kg bw/day (nominal)

Based on:

test mat.

Sex:

male/female

Basis for effect level:

other: 1% of benzoic acid in food, assuming 150 mg (1%) of benzoic acid per day per rat and 300 g bw of rat

2

Dose descriptor:

NOEL

Effect level:

557 mg/kg bw/day (nominal)

Based on:

other: methyl benzoate

Sex:

male/female

Target system / organ toxicity

Critical effects observed:

not specified

Any other information on results incl. tables

Table 1. Body weight gain in g (mean ± deviation)

	Control		0.5% Benzoic acid		1% benzoic acid
	Male	Female	Male	Female	Male	Female
I Generation
Week 4	70 ± 5.0	67 ± 4.1	69 ± 2.7	64 ± 2.4	75 ± 1.4	61 ± 2.2
Week 8	159 ± 6.6	124 ± 5.2	160 ± 5.0	135 ± 5.4	147 ± 2.8	133 ± 2.4
Week 12	219 ± 6.3	-	221 ± 5.6	-	237 ± 6.0	-
II Generation
Week 4	69 ± 2.3	57 ± 3.3	71 ± 2.2	60 ± 6.7	73 ± 3.3	70 ± 2.4
Week 8	167 ± 2.0	122 ± 3.6	161 ± 2.6	131 ± 3.5	158 ± 4.6	123 ± 5.3
Week 12	243 ± 5.5	-	238 ± 3.3	-	231 ± 5.6	-
III Generation
Week 4	73 ± 3.0	60 ± 3.5	68 ± 3.8	71 ± 2.4	72 ± 3.5	67 ± 3.7
Week 8	157 ± 4.5	134 ± 4.1	158 ± 5.3	137 ± 3.9	168 ± 2.0	136 ± 4.5
Week 12	240 ± 4.6	-	226 ± 5.8	-	233 ± 3.8	-
IV Generation
Week 4	93 ± 1.7	76 ± 4.8	84 ± 2.9	70 ± 3.1	73 ± 5.3	72 ± 3.5
Week 8	189 ± 5.3	137 ± 4.3	168 ± 3.7	143 ± 2.4	159 ± 6.2	134 ± 4.5
Week 12	255 ± 4.6	-	245 ± 4.4	-	240 ± 4.4	-

Table 2. The organ weights of animals of the 3rd generation (% of bodyweight)

	Control		0.5% Benzoic acid		1% Benzoic acid
	Male	Female	Male	Female	Male	Female
Bodyweight, g	326 ± 5	262 ± 5	329 ± 5	276 ± 5	316 ± 3	248 ± 6
Brain	0.57 ± 0.01	0.69 ± 0.02	0.58 ± 0.01	0.68 ± 0.01	0.61 ± 0.00	0.75 ± 0.02
Heart	0.34 ± 0.02	0.35 ± 0.01	0.32 ± 0.01	0.39 ± 0.01	0.33 ± 0.01	0.35 ± 0.01
Liver	3.49 ± 0.1	5.32 ± 0.3	3.34 ± 0.1	5.19 ± 0.2	3.49 ± 0.1	5.40 ± 0.2
Spleen	0.21 ± 0.00	0.25 ± 0.01	0.21 ± 0.04	0.23 ± 0.01	0.22 ± 0.01	0.25 ± 0.01
Rein	0.72 ± 0.02	0.8 ± 0.03	0.70 ± 0.04	0.79 ± 0.01	0.74 ± 0.02	0.78 ± 0.02
Testes	0.85 ± 0.03	-	0.83 ± 0.04	-	0.92 ± 0.01	-

Applicant's summary and conclusion

Conclusions:

No effects were noted after chronic dietary exposure of rats to 1% benzoic acid (equivalent to 500 mg/kg bw/day). The NOEL for benzoic acid can be converted to a NOEL for methyl benzoate of 557 mg/kg bw/day.

Executive summary:

In a life long chronic multi-generation study 2 experimental groups of 20 male and 20 female rats were treated with 0.5 and 1% of benzoic acid in food. The control group received untreated food and consisted also of 20 male and 20 female rats. The first and the second generations were treated lifelong, the 3rd generation was exposed for 16 weeks and the 4th generation was exposed until breeding. No effects on body weight and food intake were detected in all 4 generations. Liver weight increase in females of the 3rd generation was considered as not treatment-related and interpreted as weight increase during lactation and due to variation in litter size. No effects after histopathological examinations were detected in the treated animals of the 3rd generation. Causes of death in this chronic study were not investigated. Based on the data of this study, the NOEL for chronic exposure to benzoic acid in the diet is 1% (corresponding to 500 mg/kg bw/day benzoic acid and 557 mg/kg bw/day methyl benzoate).