2,4-dichlorotoluene

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

Study period:

1989-02-17 to 1989-03-10

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1989

Report date:

1989

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

GLP compliance:

yes (incl. QA statement)

Type of assay:

bacterial reverse mutation assay

Test material

Test material information

Constituent 1

Reference substance name:

Benzene, 2,4-dichloro-1-methyl-

IUPAC Name:

Benzene, 2,4-dichloro-1-methyl-

Constituent 2

Reference substance name:

2,4-dichlorotoluene

EC Number:

202-445-8

EC Name:

2,4-dichlorotoluene

Cas Number:

95-73-8

Molecular formula:

C7H6Cl2

IUPAC Name:

2,4-dichloro-1-methylbenzene

Details on test material:

name of substance: 2,4-Dichlorotoluene
content: 99,4 % (analytical result dated November 30, 1988)
appearance: clear aqueous liquid
storage: refrigerator

Method

Target gene:

In the Salmonella typhimurium strains (TA 1535, TA 100, TA 1537, TA 1538, TA 98) the amino acid histidine locus is the target gene.

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:

Rat liver S-9 mix from Arochlor 1254 induced rats.

Test concentrations with justification for top dose:

0, 2.34, 9.38, 20, 37.5, 100, 150, 500, 600, 2400, 12500 µg/plate

Vehicle / solvent:

The solvent for 2,4-dichlorotoluene was ethanol and for the positive controls DMSO.

Controls

Untreated negative controls:

yes

Negative solvent / vehicle controls:

yes

Remarks:

Ethanol

Positive controls:

yes

Positive control substance:

other: sodium azide (10 µg/plate - TA 1535); nitrofurantoin (0,2 µg/plate - TA 100); 4-nitro-1,2-phenylene diamine (10 µg/plate - TA 1537 and 0,5 µg/plate - TA 98); 2-aminoanthracene (3 µg/plate - all strains)

Evaluation criteria:

A reproducible and dose-related increase in mutant counts of at least one strain is considered to be a positive result. For TA 1535, TA 100, and TA 98 this increase should be about twice the amount of negative controls, whereas for TA 1537 at least a threefold increase should be reached. Otherwise, the result is evaluated as negative.

Results and discussion

Test results

Species / strain:

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

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

cytotoxicity

Remarks:

Doses up to and including 9.38 µg/plate did not cause any bacteriotoxic effects. The range could only be used to a limit extent up to 2500 µg/plate for assessment purposes.

Vehicle controls validity:

valid

Remarks on result:

other: all strains/cell types tested

Remarks:

Migrated from field 'Test system'.

Applicant's summary and conclusion

Conclusions:

No indications of mutagenic effects of 2,4-dichlorotoluene could be found at assessable doses up to 2500 µg/plate in any of the Salmonella typhimurium strains used.

Executive summary:

In a reverse gene mutation assay in bacteria Salmonella typhimurium strains TA98, TA100, TA1535 and TA1537 were exposed to 2,4-dichlortoluene at concentrations of 0, 2.34, 9.38, 20, 37.5, 100, 150, 500, 600, 2400, 12500 µg/plate in the presence and absence of mammalian metabolic activation.

Doses higher than 9.3 µg/plate had a strain-specific bacteriotoxic effect, but could partly be used for assessment up to and including 2500 µg/plate.

No indications of mutagenic effects of 2,4-dichlorotoluene could be found at assessable doses up to 2500 µg/plate in any of the Salmonella typhimurium strains used.