Acetic acid, C11-14-branched alkyl esters, C13-rich

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:

24 November 1993 - 23 December 1993

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1994

Report date:

1994

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

EPA OTS 798.5265 (The Salmonella typhimurium Bacterial Reverse Mutation Test)

Deviations:

yes

Remarks:

analysis of the test substance mixtures was not performed

GLP compliance:

yes

Type of assay:

bacterial reverse mutation assay

Test material

Test material information

Constituent 1

Reference substance name:

Acetic acid, C11-14-isoalkyl esters, C13-rich

EC Number:

283-740-9

EC Name:

Acetic acid, C11-14-isoalkyl esters, C13-rich

Cas Number:

84712-50-5

Molecular formula:

C15H30O2

IUPAC Name:

Acetic acid, C11-14-isoalkyl esters, C13-rich

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Source and lot/batch No.of test material: Exxon Chemical Company/ Lot Number: 2-93-15
- Expiration date of the lot/batch: 31 October 1998

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material: Room Temperature
- Solubility and stability of the test substance in the solvent/vehicle: The test substance was soluble in DMSO.

Method

Species / strain

Species / strain / cell type:

other: S. typhimurium TA 1535, TA 1537, TA 1538, TA 98 and TA 100

Details on mammalian cell type (if applicable):

CELLS USED
- Source of cells: Dr. B. N. Ames, Department of Biochemistry, University of California, Berkeley, California.

Metabolic activation:

with and without

Metabolic activation system:

Liver homogenate from the livers of Aroclor 1254 pretreated Sprague Dawley rats

Test concentrations with justification for top dose:

625, 1250, 1500, 500, 10000 ug/ml.

In a toxicity pretest a dose range from 1 to 10,000 ug per plate where tested. An increase in the number of revertant colonies was not observed at any of the concentrations tested. A reduction in the number of revertant colonies was observed at test concentrations 50 ug/plate and 10,000 ug/plate. It is was clear if this decrease is related to toxicity or the normal variation in colony counts. The test substance appeared to bead on the plates at test concentrations of 2,000 to 10,000 ug/plate.

Vehicle / solvent:

- Vehicle(s)/solvent(s) used: DMSO

Controls

Untreated negative controls:

yes

Negative solvent / vehicle controls:

yes

True negative controls:

not specified

Positive controls:

yes

Positive control substance:

9-aminoacridine

2-nitrofluorene

other: 2-Aminoanthracene, N-Methyl-N-Nitro-N-Nitrosoguanidine

Details on test system and experimental conditions:

METHOD OF APPLICATION: in agar

DURATION
- Exposure duration: 2 days

Evaluation criteria:

An individual dose is considered positive if the mean colony count on the test plates is equal to or greater than three times the mean number of spontaneous revertants on the vehicle control plates. A positive result for the assay is defined as a reproducible dose-related increase in the number of revertant colonies over at least 3 concentrations of test material including at least one positive dose

Statistics:

The mean plate count and standard deviation for each dose point were determined.

Results and discussion

Test results

Key result

Species / strain:

other: S. typhimurium TA 1535, TA 1537, TA 1538, TA 98 and TA 100

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

Positive controls validity:

valid

Any other information on results incl. tables

Results tables can be found in the attachment to this RSS.

Applicant's summary and conclusion

Conclusions:

Exxate 1300 (MRD-93-689) was not considered to be mutagenic under the conditions of this assay.

Executive summary:

The microbial mutagenesis assay (Ames Assay), developed by B. N. Ames and coworkers (1975) is a test for the ability of a compound to cause reverse mutation at the histidine locus in bacteria (from nutritional histidine dependence to histidine independence). Five special tester strains of Salmonella typhimurium, which were sensitive to frameshift or base pair mutagens, were employed. Positive test results are considered to provide presumptive evidence of mutagenic potential in mammalian species.

This assay was conducted in compliance with the U.S. EPA, Federal Insecticide, Fungicide and Rodenticide Act (FIFRA); Good Laboratory Practice Standards, 40 CFR Part 160, 1989 and the U.S. EPA, Toxic Substance and Control Act (TSCA) Test Guidelines 40 CFR 798.5265, 1985, to determine if Exxate 1300 (MRD-93-689) was capable of causing reverse mutations in these special tester strains of bacteria with and without metabolic activation.

The test substance was diluted in DMSO. A toxicity pretest was performed to determine the highest concentration of test substance to be used in the initial assay. Test concentrations of 1 to 10,000 µg/plate were tested with and without metabolic activation in tester strain TA98.

The test substance did not induce an increase in the number of revertant colonies at any of the concentrations tested. A reduction in the number of revertant colonies was observed at test concentrations 50 µg/plate and 10,000 µg/plate without metabolic activation. It is not clear if this decrease is related to toxicity or the normal variation of colony counts.

Based on these results, test concentrations of 625 to 10,000 µg/plate were tested in the initial assay. A repeat assay was performed using test concentrations of 156 to 2,500 µg/plate.

Neither a positive dose nor a dose related increase was observed for any of the tester strains with or without metabolic activation. Thus, Exxate 1300 (MRD-93-689) was not considered to be mutagenic under the various conditions of testing.

Toxicity, as seen by either a reduction in the number of reverent colonies or reduction in the background lawn, was not observed.

Both the negative and positive controls responded in an appropriate manner.