2,6-difluorobenzamide

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

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Non-GLP, near guideline study, available as unpublished reoprt, no restrictions, fully adequate for assessment.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1987

Report date:

1987

Materials and methods

Test guideline

Test guideline 1

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

Test guideline 2

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 472 (Genetic Toxicology: Escherichia coli, Reverse Mutation Assay)

GLP compliance:

no

Type of assay:

bacterial reverse mutation assay

Test material

Test material information

Constituent 1

Reference substance name:

2,6-difluorobenzamide

EC Number:

241-972-8

EC Name:

2,6-difluorobenzamide

Cas Number:

18063-03-1

Molecular formula:

C7H5F2NO

IUPAC Name:

2,6-difluorobenzamide

Details on test material:

Batch number: 722.35
ST number: ST86/206
Characterisation: no purity data available- commercial sample
Appearance: white powder

Method

Target gene:

histidine

Species / strain

Species / strain 1

Species / strain / cell type:

S. typhimurium TA 1535, TA 1537, TA 98, TA 100 and E. coli WP2

Species / strain 2

Species / strain / cell type:

S. typhimurium TA 1538

Metabolic activation:

with and without

Metabolic activation system:

rat liver S9 (pre-treated with Aroclor 1254)

Test concentrations with justification for top dose:

31.25, 62.5, 125, 500, 1000, 200 and 4000 μg/plate

Vehicle / solvent:

DMSO

Controls

Untreated negative controls:

yes

Negative solvent / vehicle controls:

yes

True negative controls:

no

Positive controls:

yes

Positive control substance:

other: benzo(a)pyrene, sodium azide, neutral red and potassium dichromate

Details on test system and experimental conditions:

METHOD OF APPLICATION: in agar (plate incorporation)

DURATION
- Exposure duration: 48-72 h at 37 °C

NUMBER OF REPLICATIONS: three plates per dose/control

Evaluation criteria:

Results are expressed as a ratio: mean number of revertant colonies per treated plate / mean number of revertant colonies per control plate.
Reproducible values of 2.5 x a control value or greater are considered to indicate a mutagenic response.

Results and discussion

Test results

Test results 1

Species / strain:

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

Test results 2

Species / strain:

S. typhimurium TA 1538

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

Additional information on results:

The test compound was totally miscible in the test system at amounts up to 4000 µg per plate.

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 without metabolic activation
negative with metabolic activation

It was concluded that the test substance did not induce reverse gene mutation in the selected bacterial tester strains under the experimental conditions described.

Executive summary:

The mutagenic activity of the test substance was investigatedin agar layer cultures of selected bacterial tester strains of Salmonella typhimurium and Escherichia coli. Assays were performed both in the presence and in the absence of a S9 microsomal fraction obtained from a liver homogenate from rats pre-treated with Arochlor 1254.

It was concluded that the test substance did not induce reverse gene mutation in the selected bacterial tester strains under the experimental conditions described.