2-tert-butylhydroquinone

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

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Justification for type of information:

Data is from study report

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1983

Report date:

1983

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

Principles of method if other than guideline:

Ames assay was performed to determine the mutagenic nature of the test chemical

GLP compliance:

not specified

Type of assay:

bacterial reverse mutation assay

Test material

Test material information

Constituent 1

Reference substance name:

2-tert-butylhydroquinone

EC Number:

217-752-2

EC Name:

2-tert-butylhydroquinone

Cas Number:

1948-33-0

Molecular formula:

C10-H14-O2

IUPAC Name:

2-tert-butylbenzene-1,4-diol

Details on test material:

- Name of test material: 2-tert-butylhydroquinone
- Molecular formula: C10H14O2
- Molecular weight: 166.22
- Substance type: Organic
- Physical state: Solid

Method

Target gene:

Histidine

Species / strain

Species / strain / cell type:

S. typhimurium, other: TA1537, TA1535, TA1538, TA98, TA100

Details on mammalian cell type (if applicable):

Not applicable

Additional strain / cell type characteristics:

not specified

Cytokinesis block (if used):

No data

Metabolic activation:

with and without

Metabolic activation system:

RAT, LIVER, S-9, AROCLOR 1254

Test concentrations with justification for top dose:

The test chemical was tested in the Ames bioassay at levels upto 13.9 mg/L (0.450 mg/plate) without S-9 activation 82.3 mg/L (2.7 mg/plate) with S-9 activation.

Vehicle / solvent:

Dimethyl sulfoxide (DMSO)

Controls

Controls 1

Untreated negative controls:

not specified

Negative solvent / vehicle controls:

yes

Remarks:

Dimethyl sulfoxide (DMSO)

True negative controls:

not specified

Positive controls:

yes

Positive control substance:

other: 2-aminoanthracene

Remarks:

With S9 activation

Controls 2

Untreated negative controls:

not specified

Negative solvent / vehicle controls:

yes

Remarks:

Dimethyl sulfoxide (DMSO)

True negative controls:

not specified

Positive controls:

yes

Positive control substance:

sodium azide

Remarks:

Without S9 activation for S. typhimurium TA 1535

Controls 3

Untreated negative controls:

not specified

Negative solvent / vehicle controls:

yes

Remarks:

Dimethyl sulfoxide (DMSO)

True negative controls:

not specified

Positive controls:

yes

Positive control substance:

9-aminoacridine

Remarks:

Without S9 activation for S. typhimurium TA 1537

Controls 4

Untreated negative controls:

not specified

Negative solvent / vehicle controls:

yes

Remarks:

Dimethyl sulfoxide (DMSO)

True negative controls:

not specified

Positive controls:

yes

Positive control substance:

other: picrolonic acid

Remarks:

Without S9 activation for S. typhimurium TA 1538

Controls 5

Untreated negative controls:

not specified

Negative solvent / vehicle controls:

yes

Remarks:

Dimethyl sulfoxide (DMSO)

True negative controls:

not specified

Positive controls:

yes

Positive control substance:

other: ICR-191

Remarks:

Without S9 activation for S. typhimurium TA 98

Controls 6

Untreated negative controls:

not specified

Negative solvent / vehicle controls:

yes

Remarks:

Dimethyl sulfoxide (DMSO)

True negative controls:

not specified

Positive controls:

yes

Positive control substance:

sodium azide

Remarks:

Without S9 activation for S. typhimurium TA 100

Details on test system and experimental conditions:

No data

Rationale for test conditions:

No data

Evaluation criteria:

The plates were observed for an increase in number of revertants/plate

Statistics:

No data

Results and discussion

Test results

Test results 1

Species / strain:

S. typhimurium TA 1535

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

not specified

Vehicle controls validity:

not specified

Untreated negative controls validity:

not specified

Positive controls validity:

not specified

Test results 2

Species / strain:

S. typhimurium TA 1537

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

not specified

Vehicle controls validity:

not specified

Untreated negative controls validity:

not specified

Positive controls validity:

not specified

Test results 3

Species / strain:

S. typhimurium TA 1538

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

not specified

Vehicle controls validity:

not specified

Untreated negative controls validity:

not specified

Positive controls validity:

not specified

Test results 4

Species / strain:

S. typhimurium TA 98

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

not specified

Vehicle controls validity:

not specified

Untreated negative controls validity:

not specified

Positive controls validity:

not specified

Test results 5

Species / strain:

S. typhimurium TA 100

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

not specified

Vehicle controls validity:

not specified

Untreated negative controls validity:

not specified

Positive controls validity:

not specified

Additional information on results:

Without the metabolic mixture, the 50% population survival dose was observed to be between 31 and 9.8 mg/L. A significant decrease in 2-tert-butylhydroquinone (TBHQ) toxicity was observed in the presence of the S-9 metabolic mixture with 50% population survival occurring at between 30.5 and 96.3 mg/L.

Remarks on result:

other: No mutagenic potential

Applicant's summary and conclusion

Conclusions:

The test chemical was negative when tested in the standard Ames test in five strains of Salmonella typhimurium TA1537, TA1535, TA158, TA98 and TA100 both with and without rat liver S-9 microsomal activation and hence it is not likely to classify as a gene mutant in vitro.

Executive summary:

Ames assay was performed to determine the mutagenic nature of the test chemical. The study was performed using Salmonella typhimurium TA1537, TA1535, TA158, TA98 and TA100 both with and without rat liver S-9 microsomal activation system. In the study reported here, the test chemical was tested in the Ames bioassay at levels upto 13.9 mg/L (0.450 mg/plate) without S-9 activation 82.3 mg/L (2.7mg/plate) with S-9 activation. The maximum concentrations used in these studies resulted in reduced viability of the test organisms, indicating that the test chemical was being tested at biologically significant concentrations. The difference in maximum test concentrations as a function of the presence of S-9 indicates that the metabolite(s) of the test chemical formed by microsomal enzymes in the s-9 have less biological impact on the test organism than the test chemical itself. In the Ames bioassay , no test chemical- related increases in revertants were noted in any test strain either with or without S-9 liver enzymes. HQ was negative when tested in the standard Ames test in five strains of Salmonella typhimurium , both with and without rat liver S-9 microsomal activation.