2-chlorobuta-1,3-diene

Genetic toxicity: in vitro

Administrative data

Endpoint:

in vitro cytogenicity / chromosome aberration study in mammalian cells

Remarks:

Type of genotoxicity: chromosome aberration

Type of information:

migrated information: read-across based on grouping of substances (category approach)

Adequacy of study:

supporting study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: acceptable well-documented publication which meets basic scientific principles

Cross-reference

Reason / purpose for cross-reference:

reference to same study

Data source

Reference

Reference Type:

publication

Title:

In vitro genotoxicity testing of (1-chloroethenyl)oxirane, a metabolite of ß-chloroprene

Author:

Himmelstein MW, Gladnick NL, Donner EM, Snyder RD, Valentine R.

Year:

2001

Bibliographic source:

Chemico-Biological Interactions 135-136: 701-713

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 473 (In Vitro Mammalian Chromosome Aberration Test)

Principles of method if other than guideline:

The methods of Fenech & Morley (1985), Fenech (2000) and Kalweit et al (1999) were followed, and were broadly comparable to the guideline.

GLP compliance:

not specified

Remarks:

published study

Type of assay:

in vitro mammalian chromosome aberration test

Test material

Test material information

Constituent 1

Reference substance name:

chloroprene monoepoxide

IUPAC Name:

chloroprene monoepoxide

Constituent 2

Reference substance name:

3123-77-22

IUPAC Name:

3123-77-22

Details on test material:

Chloroprene monoepoxide (CEO); (1-chloroethenyl)oxirane, is the main metabolite produced by in vitro metabolism of chloroprene. The test material had a purity of >98%, was synthesised (methods published in Himmelstein et al (2001) Chemico-Biological Interactions 135-136: 267-284), and was stored frozen with nitrogen in the vial headspace.

Method

Target gene:

Not applicable - chromosome aberration study.

Species / strain

Species / strain / cell type:

Chinese hamster lung fibroblasts (V79)

Metabolic activation:

without

Test concentrations with justification for top dose:

0 to 0.943 mM, the upper concentrations corresponded to those below which cytotoxicity was observed.

Vehicle / solvent:

1% DMSO

Controls

Negative solvent / vehicle controls:

yes

Positive controls:

yes

Positive control substance:

no

Details on test system and experimental conditions:

Chinese hamster V79 cells were seeded onto 4-well tissue culture slides at ca. 2000 - 5000 cells/well, covered, and allowed to grow at 37°C in an humidified atmosphere of 5% CO2 for 24 h. The covers of the well slides were removed and the slides were placed into sterile bottles filled to the rim with complete culture media (Eagle's minimum essential medium with 10% fetal bovine serum) without S9 mix. The test substance was diluted in DMSO and injected into the bottles with a syringe followed by gentle mixing.
The cells were exposed for 3 h then removed from the exposure bottles. The covers were replaced, and fresh medium containing cytochalasin B was added. The cells were cultured for an additional 16 h. After the incubation, the cells were treated with hyptonic solution and stained wth Dif-Qwik in situ on the slides. A minimum of 500 binucleated cells were scored for micronuclei, and assessed for the proportion of binucleated cells and mononucleated cells.
Cytotoxicity was determined by comparing the number of binucleated cells in treated groups to the control, and assessing cell morphology.

Evaluation criteria:

For a chemical to be classified as positive, a concentration-dependent increase in the frequency of micronucleated binucleated cells was required, with at least one concentration producing approximately a three-fold or higher MN frequency than that observed in the vehicle control.

Statistics:

Not required.

Results and discussion

Test results

Species / strain:

Chinese hamster lung fibroblasts (V79)

Metabolic activation:

without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

cytotoxicity

Vehicle controls validity:

valid

Additional information on results:

No precipitation was observed. Cytotoxicity, observed as a reduced proportion of binucleated cells and altered cell morphology was observed at test concentrations of 0.175 mM and above.
The MN frequency of the vehicle controls was 0.9±0.6% (1 SD for 6 determinations).
Concentrations analysed for aberrations were between 0.02 and 0.2 mM. There was no evidence of mutagenicity.

Remarks on result:

other: strain/cell type: V79

Remarks:

Migrated from field 'Test system'.

Any other information on results incl. tables

The use of positive controls was not reported, however 3,4-epoxy-1-butene and 1,2:3,4-diepoxybutane were also evaluated and found to be clearly clastogenic.

Applicant's summary and conclusion

Conclusions:

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

Chloroprene monoepoxide (CEO), an in vitro metabolite of chloroprene, was found to be non-clastogenic to Chinese hamster V79 cells in vitro.

Executive summary:

Chloroprene monoepoxide (CEO), an in vitro metabolite of chloroprene, was found to be non-clastogenic to Chinese hamster V79 cells when tested up to concentrations of 0.2 mM in vitro.