Dichloromethylbenzene

Genetic toxicity: in vitro

Administrative data

Endpoint:

in vitro gene mutation study in bacteria

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2014

Report date:

2014

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

Principles of method if other than guideline:

The test item 'Dichlortoluol Gemisch' was initially investigated for point mutagenic effects in the plate incorporation test. The test item, dissolved in DMSO, was administered in doses of up to and including 5000 µg per plate without and with S9 mix on the five Salmonella typhimurium LT2 mutant strains TA1535, TA100, TA1537, TA98 and TA102, according to the OECD guideline 471.
The test item was investigated in an independent repeat using the preincubation modification in doses of up to and including 500 µg per plate without and with S9 mix. Other experimental conditions remained unchanged.

GLP compliance:

yes

Type of assay:

bacterial reverse mutation assay

Test material

Test material information

Constituent 1

Reference substance name:

Dichloromethylbenzene

EC Number:

249-854-8

EC Name:

Dichloromethylbenzene

Cas Number:

29797-40-8

Molecular formula:

C7H6Cl2

IUPAC Name:

(dichloromethyl)benzene

Details on test material:

Test Item: Dichlortoluol Gemisch
CAS No.: 29797-40-8
Molecular Formula: C7H6CI2
CAS name: Dichloromethyl-benzene
Molecular Mass (g/mol): 161.0
Purity: 99.1%
Appearance: colorless liquid
Storage: room temperature

Method

Species / strain

Species / strain / cell type:

S. typhimurium, other: TA1535, TA100, TA1537, TA98 and TA102

Additional strain / cell type characteristics:

other: All S. typhimurium strains were checked for of rfa-mutation ("deep rough"), for their resistance to ampicillin to establish the presence ofthe R-factor/pKM101-plasmid and for their resistance to tetracycline to establish the presence ofthe pAQ1-plasmid

Metabolic activation:

with and without

Metabolic activation system:

S9 mix

Test concentrations with justification for top dose:

plate incorporation test: up to and including 5000 µg per plate without and with S9 mix
preincubation method: up to and including 500 µg per plate without and with S9 mix

Controls

Untreated negative controls:

yes

Negative solvent / vehicle controls:

yes

True negative controls:

not specified

Positive controls:

yes

Positive control substance:

2-nitrofluorene

sodium azide

cumene hydroperoxide

mitomycin C

other: 4-Nitro-1,2-phenylene diamine, 2-aminoanthracene

Results and discussion

Test results

Species / strain:

S. typhimurium, other: TA1535, TA100, TA1537, TA98 and TA102

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

other: Doses up to and including 160 µg per plate did not cause any bacteriotoxic effects. At higher doses, the substance had a strain-specific bacteriotoxic effect

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

Positive controls validity:

valid

Remarks on result:

other: other: TA1535, TA100, TA1537, TA98 and TA102

Any other information on results incl. tables

Evidence of mutagenic activity ofthe test item was not seen. No biologically relevant increase in the mutant count, in comparison to the solvent controls, was observed in any of the strains tested, without and with S9 mix, in the plate incorporation as well in the preincubation modification, under the experimental conditions applied.

Applicant's summary and conclusion

Conclusions:

Interpretation of results: negative

Executive summary:

The test item 'Dichlortoluol Gemisch' was initially investigated for point mutagenic effects in the plate incorporation test. The test item, dissolved in DMSO, was administered in doses of up to and including 5000 µg per plate without and with S9 mix on the five Salmonella typhimurium LT2 mutant strains TA1535, TA100, TA1537, TA98 and TA102, according to the OECD guideline 471. Doses up to and including 160 µg per plate did not cause any bacteriotoxic effects. At higher doses, the substance had a strain-specific bacteriotoxic effect. This range could be used strain-specific up to 5000 µg per plate for assessment purposes.

The test item was investigated in an independent repeat using the preincubation modification in doses of up to and including 500 µg per plate without and with S9 mix. Other experimental conditions remained unchanged. Doses up to and including 16 µg per plate did not cause any bacteriotoxic effects. At higher doses, the substance had a strain-specific bacteriotoxic effect. This range could be used strain-specific up to 500 µg per plate for assessment purposes.

Evidence of mutagenic activity of the test item was not seen. No biologically relevant increase in the mutant count, in comparison to the solvent controls, was observed in any of the strains tested, without and with S9 mix, in the plate incorporation as well in the preincubation modification, under the experimental conditions applied.

Therefore, the test item was considered to be non-mutagenic without and with S9 mix in the plate incorporation as well as in the preincubation modification of the Salmonella/microsome test.