1-chloro-1,1-difluoroethane

Genetic toxicity: in vitro

Administrative data

Endpoint:

genetic toxicity in vitro

Remarks:

Type of genotoxicity: other: in vitro indicator assay

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: GLP-compliant study, available as unpublished report, minor restrictions in design and reporting, but otherwise adequate for assessment (SIDS score: 2c)

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1977

Report date:

1978

Materials and methods

Principles of method if other than guideline:

Evaluation of the ability to induce malignant transformation of BALB/3T3 cells in vitro, according to the basic methodology developed by T. Kakunaga (1973)

GLP compliance:

yes

Type of assay:

in vitro mammalian cell transformation assay

Test material

Test material information

Constituent 1

Reference substance name:

1-chloro-1,1-difluoroethane

EC Number:

200-891-8

EC Name:

1-chloro-1,1-difluoroethane

Cas Number:

75-68-3

Molecular formula:

C2H3ClF2

IUPAC Name:

1-chloro-1,1-difluoroethane

Details on test material:

1-chloro-1,1-difluoromethane: no data, purity not stated

Method

Species / strain

Species / strain / cell type:

mammalian cell line, other: BALB73T3

Metabolic activation:

without

Test concentrations with justification for top dose:

Not determined; exposure to the test substance for 1, 2, 4, 6 and 24 h.

Vehicle / solvent:

None

Controls

Untreated negative controls:

yes

Negative solvent / vehicle controls:

yes

True negative controls:

no

Positive controls:

yes

Positive control substance:

3-methylcholanthrene

Details on test system and experimental conditions:

Number of replicates: 10

Evaluation criteria:

Number of foci per set of replicate plates for each time exposure.

Statistics:

Not stated

Results and discussion

Test results

Species / strain:

mammalian cell line, other: BALB/3T3 Cell line

Metabolic activation:

without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity

Vehicle controls validity:

not applicable

Untreated negative controls validity:

valid

Positive controls validity:

not valid

Additional information on results:

The positive control substance did not give usual response in this evaluation; it was low by 2-3 fold.

Remarks on result:

other: all strains/cell types tested

Remarks:

Migrated from field 'Test system'.

Any other information on results incl. tables

Table 1. Summary of data

Test substance	Concentration	Number of plates scored											Total number of foci	Mean number of foci/plate	Number of foci/plate corrected for spontaneous
		1	2	3	4	5	6	7	8	9	10
Negative control (media)	-	2	2	0	0	0	0	2	3	0	C		9	1.0	-
Positive control (3-MC)	5 g/ml	2	2	1	2	2	3	2	1	1	C		16	1.7	0.7
Isotron 142-B	1 h	1	1	2	1	2	1	2	0	C	C		10	1.2	0.2
Isotron 142-B	2 h	1	2	0	1	1	1	0	1	0	1	8		0.8	-
Isotron 142-B	4 h	2	2	1	0	1	2	1	2	1	C	12		1.3	0.3
Isotron 142-B	6 h	1	1	1	0	1	0	C	C	C	C	4		0.6	-
Isotron 142-B	24 h	2	2	1	1	1	1	0	2	C	C	10		1.2	0.2

3 -MC = 3 -methylchloroanthrene

C = plate was contaminated and not scored

* data significant from the negative control at p = 0.05

** data significant from the negative control at p = 0.01

Applicant's summary and conclusion

Conclusions:

Interpretation of results (migrated information):
negative

Compound was not active in this BALB/3T3 cell transformation assay as it did not produce any significant increase in the transformed clones compared to the untreated control .

Executive summary:

The ability of 1-chloro-1,1-difluoroethane to induce malignant transformation in BALB/3T3 cell transformation assay in vitro was evaluated, by adding 10 s of gas into culture flasks and using 1 h, 2 h, 4 h, 6 h and 24 h exposure times. The substance was not active in the assay and did not produce any significant increased in transofrmed clones compared to the untreated control. It should however be noted that the positive control (3 -methylchloroanthrene) did not produce a usual responce in this evaluation, it was low by 2 -3 fold.