2-bromo-4-chloro-1-isopropylbenzene

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:

2015

Report date:

2015

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

Version / remarks:

21 July 1997

Deviations:

yes

Remarks:

2-aminoanthracene was used as sole positive control for metabolic activation

GLP compliance:

yes (incl. QA statement)

Type of assay:

bacterial reverse mutation assay

Test material

Test material information

Constituent 1

Reference substance name:

2-bromo-4-chloro-1-(propan-2-yl)benzene

EC Number:

696-543-1

Cas Number:

1369828-32-9

Molecular formula:

C9H10BrCl

IUPAC Name:

2-bromo-4-chloro-1-(propan-2-yl)benzene

Method

Target gene:

his operon, trp operon

Species / strain

Species / strain 1

Species / strain / cell type:

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

Species / strain 2

Species / strain / cell type:

E. coli WP2 uvr A

Metabolic activation:

with and without

Metabolic activation system:

cofactor-supplemented post-mitochondrial fraction (S9 mix), prepared from the livers of male rats, treated with phenobarbital and β-naphthoflavone (80 mg/kg bw)

Test concentrations with justification for top dose:

Initial Mutation Test (plate incorporation test, Exp. I):
- 1.581, 5, 15.81, 50, 158.1, 500, 1581 and 5000 μg/plate (with and without metabolic activation, all Salmonella typhimurium strains and E. coli WPA uvr A)

Confirmatory Mutation Test (pre-incubation procedure, Exp. IIa):
- 1.581, 5, 15.81, 50, 158.1, 500, 1581 and 5000 μg/plate (with and without metabolic activation, only E. coli WPA uvr A)

Complementary Confirmatory Mutation Test (pre-incubation procedure, Exp. IIb):
- 0.01581, 0.05, 0.1581, 0.5, 1.581, 5, 15.81, 50, 158.1, 500, 1581 and 5000 μg/plate (without metabolic activation, all Salmonella typhimurium strains)
- 0.1581, 0.5, 1.581, 5, 15.81, 50, 158.1, 500, 1581 and 5000 μg/plate (with metabolic activation, all Salmonella typhimurium strains)

Vehicle / solvent:

- Vehicle(s)/solvent(s) used: DMSO

Controls

Untreated negative controls:

yes

Remarks:

untreated control

Negative solvent / vehicle controls:

yes

Remarks:

DMSO and distilled water

True negative controls:

no

Positive controls:

yes

Positive control substance:

9-aminoacridine

sodium azide

methylmethanesulfonate

other: 4-nitro-1,2-phenylene-diamine (NPD); 2-aminoanthracene (2AA)

Results and discussion

Test results

Test results 1

Species / strain:

S. typhimurium TA 98

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

cytotoxicity

Remarks:

in Exp. I at 5000 μg/plate, -S9 mix, in the Exp. IIb at 500 and 158.1 μg/plate, +S9 mix, at 50 and 15.81 μg/plate, -S9 mix

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

Positive controls validity:

valid

Test results 2

Species / strain:

S. typhimurium TA 100

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

cytotoxicity

Remarks:

in the Exp. IIb 500 and 158.1 μg/plate, +S9 mix, at 50 and 15.81 μg/plate, -S9 mix

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

Positive controls validity:

valid

Test results 3

Species / strain:

S. typhimurium TA 1535

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

cytotoxicity

Remarks:

in Exp. I at 500, 1581 and 5000 μg/plate, +/-S9 mix and in Exp. IIb at 500 and 158.1 μg/plate, +S9 mix, at 50, 15.81 and 5 μg/plate, -S9 mix.

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

Positive controls validity:

valid

Test results 4

Species / strain:

S. typhimurium TA 1537

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

cytotoxicity

Remarks:

in Exp. I at 5000 μg/plate, +/-S9 mix and at 1581 μg/plate, -S9 mix and in Exp. IIb at 500 and 158.1 μg/plate, +S9 mix, at 50 and 15.81 μg/plate, -S9 mix

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

Positive controls validity:

valid

Test results 5

Species / strain:

E. coli WP2 uvr A

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity nor precipitates, but tested up to recommended limit concentrations

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

Positive controls validity:

valid

Remarks on result:

other:

Remarks:

Insolubility (microdrops) was detected in Exp. I at 5000 μg/plate +/-S9 mix and at 1581 μg/plate +S9 mix.

Applicant's summary and conclusion

Conclusions:

The potential of the test substance to induce gene mutations was examined in 4 Salmonella typhimurium strains TA98, TA100, TA102, TA1535 and TA1537 and in one E. coli strain WP2 uvrA in at two independent experiments, each carried out without and with metabolic activation. The first experiment was carried out as a plate incorporation test and the second as a preincubation test. Based on the results of the conducted study the test material did not exhibit mutagenic properties in bacteria with or without metabolic activation.