Exo-1,7,7-trimethylbicyclo[2.2.1]hept-2-yl propionate

Genetic toxicity: in vitro

Administrative data

Endpoint:

in vitro gene mutation study in bacteria

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1982

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

comparable to guideline study with acceptable restrictions

Data source

Reference

Reference Type:

publication

Title:

Study of artificial flavouring substances for mutagenicity in the salmonella/microsome, Basc and micronucleus tests.

Author:

Wild D, King MT, Gocke E and Eckhardt K.

Year:

1983

Bibliographic source:

Fd Chem. Toxic. Vol. 21, No. 6, pp. 707-719, 1983

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

Deviations:

yes

Remarks:

Incomplete strain selection/ test concentrations not cleary specified and top-dose is below the recommended maximum concentration without a clear justification

GLP compliance:

no

Type of assay:

bacterial reverse mutation assay

Test material

Test material information

1

Reference substance name:

Exo-1,7,7-trimethylbicyclo[2.2.1]hept-2-yl propionate

EC Number:

220-410-5

EC Name:

Exo-1,7,7-trimethylbicyclo[2.2.1]hept-2-yl propionate

Cas Number:

2756-56-1

Molecular formula:

C13H22O2

IUPAC Name:

1,7,7-trimethylbicyclo[2.2.1]hept-2-yl propionate

Test material form:

liquid

Details on test material:

STORAGE CONDITIONS - Cool (<21C), dry area in sealed containers.

Method

Target gene:

Histidine gene

Species / strain

Species / strain / cell type:

S. typhimurium TA 1535, TA 1537, TA 98 and TA 100

Metabolic activation:

with and without

Metabolic activation system:

Aroclor 1254 induced rat liver S9

Test concentrations with justification for top dose:

5 concentrations up to 3.6 mg/ plate

Vehicle / solvent:

Water or, if poorly soluble in water, DMSO

Controls

Untreated negative controls:

no

Negative solvent / vehicle controls:

not specified

True negative controls:

no

Positive controls:

yes

Positive control substance:

sodium azide

benzo(a)pyrene

Details on test system and experimental conditions:

METHOD OF APPLICATION:
The standard plate procedure was followed (Ames, McCann & Yamasaki, 1975)

DURATION
Exposure duration: 48 hours

NUMBER OF REPLICATIONS:
At least two

Evaluation criteria:

Results that met the following criteria were regarded as positive:
- a reproducible, dose-related and at least two-fold elevation of the spontaneous revertant frequency.
- Agents producing reproducible, dose-related and significant (P ≤ 0.01) but less than two-fold elevations were classified as marginally mutagenic under the experimental conditions

Statistics:

Statistical significance was determined according to the methods of Kastenbaum & Bowman (1970).

Results and discussion

Test results

Key result

Species / strain:

S. typhimurium, other: TA 1535, TA 1537, TA98 and TA 100

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

not specified

Vehicle controls validity:

not specified

Untreated negative controls validity:

not applicable

Positive controls validity:

valid

Applicant's summary and conclusion

Conclusions:

Under the conditions of the test, the test substance is not mutagenic in the Ames test in absence and presence of metabolic activation.

Executive summary:

The mutagenic activity of the test substance was evaluated in a study equivalent to OECD 471. The substance was added by principles of the standard plate procedure at five dose levels up to 3.6 mg/plate in absence and presence of Aroclor induced rat liver S9. The five tester strains included Salmonella typhimurium TA 1535, TA 100, TA 1537, TA1538 and TA98, and water or DMSO was used as vehicle. No data on cytotoxicity was provided. Sodium azide and benzo[a]pyrene were taken along as positive controls at dose levels of 0.5 µg/plate and 5 µg/plate, respectively. Based on the results of this study it is concluded that the test substance is not mutagenic in the Salmonella typhimurium reverse mutation assay.