Carbonic acid, ethyl methyl ester

Genetic toxicity: in vitro

Administrative data

Endpoint:

in vitro gene mutation study in bacteria

Remarks:

Type of genotoxicity: gene mutation

Type of information:

experimental study

Adequacy of study:

key study

Study period:

Feb 19 - Mar 10, 1993

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: The study was performed in compliance with the Good Laboratory Practice (GLP) regulations. The procedures used in this study were similar to OECD Guideline 471.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1993

Report date:

1993

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

Deviations:

no

Principles of method if other than guideline:

None

GLP compliance:

yes

Type of assay:

bacterial reverse mutation assay

Test material

Test material information

Constituent 1

Reference substance name:

-

EC Number:

433-480-9

EC Name:

-

Cas Number:

623-53-0

Molecular formula:

C4H8O3

IUPAC Name:

ethyl methyl carbonate

Method

Target gene:

HIS operon (S. thyphimurium)
TRY operon (E. coli)

Species / strain

Species / strain 1

Species / strain / cell type:

S. typhimurium TA 1535

Species / strain 2

Species / strain / cell type:

S. typhimurium TA 1537

Species / strain 3

Species / strain / cell type:

S. typhimurium TA 98

Species / strain 4

Species / strain / cell type:

S. typhimurium TA 100

Species / strain 5

Species / strain / cell type:

E. coli WP2 uvr A

Metabolic activation:

with and without

Metabolic activation system:

liver S9 mix from Phenobarbital-pretreated rats with standard co-factors

Test concentrations with justification for top dose:

The test material concentrations were used selected according to the EC and OECD guidelines for this test system and the requirements of the Labor Ministry of Japan:
1. Series: 10, 50, 100, 500, 1000, 5000 µg/plate
2. Series: 10, 50, 100, 500, 1000, 5000 µg/plate

Vehicle / solvent:

DMSO

Controls

Controls 1

Positive controls:

yes

Positive control substance:

sodium azide

Controls 2

Positive controls:

yes

Positive control substance:

other: 2-(2-Furyl)-3-(5-nitro-2-furyl)acrylamide

Controls 3

Positive controls:

yes

Positive control substance:

9-aminoacridine

Controls 4

Positive controls:

yes

Positive control substance:

other: 2-Aininoanthracene

Controls 5

Positive controls:

yes

Positive control substance:

benzo(a)pyrene

Details on test system and experimental conditions:

METHOD OF APPLICATION: preincubation

DURATION
- Preincubation period: 20 min
- Exposure duration: 48 h

The S9 fraction obtained Kan rat previously treated with phenobarbital and 5,6-benzoflavone to induce drug metabolic enzymes was purchased from Kikkoman Corporation (Chiba, Japan) and stored at -80 °C until use.


NUMBER OF REPLICATIONS: 2

Evaluation criteria:

The numbers of revertant colonies of all test substance groups were compared with those obtained from both negative control groups. The test substance was considered as positive when the following conditions were observes.

A dose related and more than 2 fold increase in the number of revertant colonies are observed.
A reproducibility is observed.

Statistics:

No statistical analysis was used in this test.

Results and discussion

Test results

Test results 1

Species / strain:

S. typhimurium TA 1535

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

Test results 2

Species / strain:

S. typhimurium TA 98

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

Test results 3

Species / strain:

S. typhimurium TA 1537

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

Test results 4

Species / strain:

S. typhimurium 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

Test results 5

Species / strain:

E. coli WP2

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

Remarks on result:

other: all strains/cell types tested

Remarks:

Migrated from field 'Test system'.

Applicant's summary and conclusion

Conclusions:

Interpretation of results (migrated information):
negative with and without metabolic activation

With and without addition of S9 mix as the external metabolizing system, the test substance was not mutagenic under the experimental conditions described.

Executive summary:

Purpose

The objective of this test is to assess the mutagenic potential of the test substance in bacterial systems compiled with the guideline that is proposed by the JMHW and JMOL. Therefore the mutagenic activity of the test substance was avluated by examining its ability to revert histidine-requiring strains of Salmonella typhimurium and tryptophane requiring E.coli in the absence and in the presence of a rat liver metabolising system (S-9).

Study Design

The procedures used in this study were in accordance or similar to OECD Guideline 471. The investigations for the mutagenic potential were performed using Salmonella typhimurium tester strains TA 98, TA 100, TA 1535, TA 1537 and in E. coli WP2 uvr A strain. The preincubation test with and without addition of liver S9 mix was used. Two independent experimental series using duplicate plates were performed.

Results

The test substance was dissolved in DMSO and tested at concentrations ranging from 10 to 5000 µg/plate. Toxicity to the bacteria was not observed.
2 -(2 -furyl)-3 -(5 -nitro-2 -furyl)acrylamide, sodium azide, and 9 -aminoacridine served as strain specific positive control test materials in the absence of S9 mix and 2-aminoanthracene and benzo[a]pyrene were used as controls in the presence of metabolic activation. Each treatment with the test materials used as positive controls led to a clear increase in revertant colonies, thus, showing the expected reversion properties of all strains and good metabolic activity of the S9 mix used.

Following test substance treatments of all the tester strains, in the absence and in the presence of S-9, no increases in revertant numbers were observed. This study was considered to have provided no evidence of any test substance mutagenic activity in this assay system.

Conclusion

With and without addition of S9 mix as the external metabolizing system, the test substance was not mutagenic under the experimental conditions described.