1,1-difluoroethylene

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:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Non-GLP, comparable to guideline study; some restrictions in reporting, acceptable for assessment.

Data source

Reference

Reference Type:

other company data

Title:

Unnamed

Year:

1979

Report date:

1979

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

GLP compliance:

no

Type of assay:

bacterial reverse mutation assay

Test material

Test material information

Constituent 1

Reference substance name:

1,1-difluoroethylene

EC Number:

200-867-7

EC Name:

1,1-difluoroethylene

Cas Number:

75-38-7

Molecular formula:

C2H2F2

IUPAC Name:

1,1-difluoroethene

Details on test material:

Purity: 99.77%

Method

Target gene:

his

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:

S9 (liver homogenate from rats induced with Aroclor 1254)

Test concentrations with justification for top dose:

0 to 50% (0 to 500,000 ppm)

Vehicle / solvent:

filtered air

Controls

Untreated negative controls:

no

Negative solvent / vehicle controls:

yes

Remarks:

filtered air

True negative controls:

no

Positive controls:

yes

Positive control substance:

other: chloro-ethylene

Details on test system and experimental conditions:

The cytotoxicity of the test sample in the presence and absence of an activation system, as measured in strain TA 1535, is the basis for selecting concentrations to be used in the mutagenisis experiment.

Exposure was in 9-liter glass chambers. The test gas is mixed with filtered air from a compressed air line and introduced into the chambers through a flow-meter system. The cultures were exposed to gaseous concentrations from 0 to 50% of the test material, for 48 hours at 37 degrees Celsius, both in absence and presence of S9-mix.

The concentrations of the test gas in the chambers are determined (by gas chromatography) at between 2 to 3 hours after the treatment is started and just before the end of the treatment.

Evaluation criteria:

The total revertant colony number at each treatment condition is compared independently with the total revertant colony number for the appropriate negative control. Significance is judged at the 0.01 probability level.
A test sample is classified as mutagenic if both a statistically significant increase in total revertant colony number (p ≤ 0.01) and a dose response (p ≤ 0.05) are observed.

Statistics:

Number of revertants for each dose group: z-test
Dose dependency: Spearman rank test.

Results and discussion

Test results

Test results 1

Species / strain:

other: S. typhimurium TA 1537, 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:

not examined

Positive controls validity:

not specified

Test results 2

Species / strain:

S. typhimurium TA 1535

Metabolic activation:

without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity

Vehicle controls validity:

valid

Untreated negative controls validity:

not examined

Positive controls validity:

valid

Test results 3

Species / strain:

S. typhimurium TA 1535

Metabolic activation:

with

Genotoxicity:

positive

Remarks:

from 10%

Cytotoxicity / choice of top concentrations:

no cytotoxicity

Vehicle controls validity:

valid

Untreated negative controls validity:

not examined

Positive controls validity:

valid

Additional information on results:

In the cytotoxicity experiment the substance was not toxic for strain TA 1535 at concentrations up to 50%.
Strain TA 1535 reverted significantly at concentrations of 10% and above only in presence of the activation system (number of revertant colonies increased maximally 2.6 times those of controls).

Remarks on result:

other: all strains/cell types tested

Remarks:

Migrated from field 'Test system'.