Dimethyl oxalate

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:

6 May 1997 - 25 June 1997

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

test procedure in accordance with national standard methods

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1997

Report date:

1997

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

other: Notification No. 700 of the Planning and Coordination Bureau, EA, No.1039 of the Pharmaceutical Affairs Bureau, MHW & No.1014 (1986) of the Basic Industries Bureau, MITI, the Notification of Ministry of the Labor, Japan, No. 77.

GLP compliance:

yes

Remarks:

GLP statement not singed by study director

Type of assay:

other: Mutagenic potential assey using a bacterial/microsome test system

Test material

Test material information

1

Reference substance name:

Dimethyl oxalate

EC Number:

209-053-6

EC Name:

Dimethyl oxalate

Cas Number:

553-90-2

Molecular formula:

C4H6O4

IUPAC Name:

dimethyl oxalate

Specific details on test material used for the study:

Name: Dimethyl oxalate
Description: white solid
Purity of the substance 99.9%

Method

Species / strain

Species / strain 1

Species / strain / cell type:

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

Species / strain 2

Species / strain / cell type:

E. coli WP2 uvr A

Metabolic activation:

with and without

Metabolic activation system:

10% liver S9

Test concentrations with justification for top dose:

Concentration-determination test:
With and without S9 mix: 4.88; 19.5; 78.1; 313; 1250 and 5000 µg/plate, for all tester strains
Mutagenicity test:
With and without S9 mix: six concentrations between 156 and 10000 µg/plate, for all tester strains
Mutagenicity confirmation test 1:
With S9 mix: 1250, 2500, 3750, 5000, 6250, 7500, 8750 and 10000 µg/plate, tester strain TA100
Mutagenicity confirmation test 2:
With and without S9 mix: 1250, 2500, 3750, 5000, 6250, 7500, 8750 and 10000 µg/plate, tester strain TA100
Mutagenicity confirmation test 3 and 4:
With and without S9 mix: 1000, 2000, 3000, 4000, 5000, 6000, 7000 and 8000 µg/plate, tester strain TA100

Vehicle / solvent:

Concentration-determination test and Mutagenicity test: water
Mutagenicity confirmation tests 1-4: DMSO

Controls

Untreated negative controls:

no

Negative solvent / vehicle controls:

yes

True negative controls:

no

Positive controls:

yes

Positive control substance:

9-aminoacridine

sodium azide

other: 2-(2-Furyl)-3-(5-nitro-2-furyl)acrylamide, 9-Aminoacridine

Details on test system and experimental conditions:

The bacterial strains were stored in -80 °C. Overnight sub-cultures of the appropriate coded stock cultures were prepared in nutrient broth and incubated at 37 °C for approximately 10 h.
The test item was tested in a concentration-determination test, mutagenicity test and four mutagenicity confirmation tests. The concentration-determination test, mutagenicity test and mutagenicity confirmation tests 1, 3 and 4 were performed according to the pre-incubation method. The mutagenicity confirmation test 2 was performed according to the plate incorporation method.

Evaluation criteria:

The response was regarded positive in principle if the maximum number or revertant colonies in the test material group increased 2-fold relative to the vehicle control group and dose-response and reproducibility were confirmed.

Results and discussion

Test results

Test results 1

Key result

Species / strain:

S. typhimurium TA 100

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

not determined

Vehicle controls validity:

valid

Untreated negative controls validity:

not examined

Positive controls validity:

valid

Test results 2

Species / strain:

S. typhimurium TA 1535

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

not determined

Vehicle controls validity:

valid

Untreated negative controls validity:

not examined

Positive controls validity:

valid

Test results 3

Species / strain:

S. typhimurium TA 98

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

not determined

Vehicle controls validity:

valid

Untreated negative controls validity:

not examined

Positive controls validity:

valid

Test results 4

Species / strain:

S. typhimurium TA 1537

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

not determined

Vehicle controls validity:

valid

Untreated negative controls validity:

not examined

Positive controls validity:

valid

Test results 5

Species / strain:

E. coli WP2 uvr A

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

not specified

Vehicle controls validity:

valid

Untreated negative controls validity:

not examined

Positive controls validity:

valid

Any other information on results incl. tables

The concentration-determination test:

The number of revertant colonies increased at 5000 µg/plate for TA100 with or without metabolic activation, which was below 2 fold value compared to that of the vehicle control. No significant increases of revertant colonies were recorded for other strains.

Mutagenicity test:

The test material induced less than 2 fold increases in the number of revertant colonies of TA100 with or without metobolic activation to the vehicle control at the concentration range in which no toxicity was observed.

Mutagenicity test, Mutagenicity confirmation tests 3 and 4

The test material induced 1.5~1.8 fold increses in the number of revertant colonies of TA100 to the vehicle control at the concentration range in which no toxicity was observed.

Applicant's summary and conclusion

Conclusions:

Interpretation of results:
Negative

The test material was judged to be non-mutagenic because it did not induce any increases in the number of revertant colonies to at least twice as many as that of vehicle control the concentration range in which no toxicity was observed.

Executive summary:

The potential of test item Dimethyl oxalate to induce mutagenicity in Salmonella typhimurium and Escherichia coli was evaluated in experimental study by using a bacterial/microsome test system in accordance with national guidelines of Japan. The test was performed in the absence and presence of a rat liver metabolizing system (S9 mix). The validity criteria of test were fulfilled. Under experimental conditions, the test substance was judged to be non-mutagenic.