Reaction mass of 4-tert-butyl-2,5-xylenol and 6-tert-butyl-2,4-xylenol

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:

comparable to guideline study

Remarks:

Meets the requirements of GLP. There are no deviations from the recommended guideline.

Data source

Reference

Reference Type:

publication

Title:

Unnamed

Year:

1994

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

JAPAN: Guidelines for Screening Mutagenicity Testing Of Chemicals

Deviations:

no

Test guideline 2

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

Deviations:

no

GLP compliance:

yes

Type of assay:

bacterial reverse mutation assay

Test material

Test material information

Constituent 1

Reference substance name:

6-tert-butyl-2,4-xylenol

EC Number:

217-533-1

EC Name:

6-tert-butyl-2,4-xylenol

Cas Number:

1879-09-0

Molecular formula:

C12H18O

IUPAC Name:

2-tert-butyl-4,6-dimethylphenol

Method

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:

S9 mix

Test concentrations with justification for top dose:

0, 6.25, 12.5, 25, 50, 100 and 200 μg/plate (-S9 mix)
0, 6.25, 12.5, 25, 50, 100, 200 and 400 μg/plate (+S9 mix)
0, 6.25, 12.5, 25, 50, 100 and 200 μg/plate (TA1537) (+S9 mix)

Vehicle / solvent:

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

Controls

Controls 1

Untreated negative controls:

yes

Negative solvent / vehicle controls:

not specified

True negative controls:

no

Positive controls:

yes

Remarks:

without metabolic activation

Positive control substance:

sodium azide

Remarks:

TA 1535: 0.5 µg/plate

Controls 2

Untreated negative controls:

yes

Negative solvent / vehicle controls:

not specified

True negative controls:

no

Positive controls:

yes

Remarks:

without metabolic activation

Positive control substance:

other: AF2 (2-(2-Furyl)-3-(5-nitro-2-furyl) acrylamide

Remarks:

TA 100, WP2: 0.01 µg/plate and TA 98: 0.1 µg/plate

Controls 3

Untreated negative controls:

yes

Negative solvent / vehicle controls:

not specified

True negative controls:

no

Positive controls:

yes

Remarks:

without metabolic activation

Positive control substance:

9-aminoacridine

Remarks:

TA 1537: 80 µg/plate

Controls 4

Untreated negative controls:

yes

Negative solvent / vehicle controls:

not specified

True negative controls:

no

Positive controls:

yes

Remarks:

with metabolic activation

Positive control substance:

other: 2-aminoanthracene

Remarks:

TA 100: 1 µg/plate; TA 1535: 2 µg/plate; WP 2: 10 µg/plate; TA 98: 0.5 µg/plate; TA 1537: 2 µg/plate

Details on test system and experimental conditions:

METHOD OF APPLICATION: plate incorporation method
NUMBER OF REPLICATIONS: 2
OTHER:
Number of plates/test: 3

Results and discussion

Test results

Test results 1

Key result

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

Vehicle controls validity:

not specified

Untreated negative controls validity:

valid

Positive controls validity:

valid

Test results 2

Key result

Species / strain:

E. coli WP2 uvr A

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity

Vehicle controls validity:

not specified

Untreated negative controls validity:

valid

Positive controls validity:

valid

Any other information on results incl. tables

Toxicity (inhibition growth) was observed at concentrations of 200 µg/plate (100 µg/plate for TA100 and TA1537) (-)S9 Mix and 400 µg/plate (200 µg/plate for TA100 and TA1537) (+) S9 Mix.

 

Applicant's summary and conclusion

Conclusions:

Not mutagenic in Salmonella typhimurium TA100, TA98, TA1535, TA1537 and Escherichia coli WP2 uvrA, with and without metabolic activation.

Executive summary:

Genotoxicity of 6-tert-butyl-2,4-xylenol was studied by the reverse mutation assay in bacteria, according to the JAPAN Guidelines for Screening Mutagenicity Testing Of Chemicals (equivalent to OECD Guideline 471). 6 -tert-Butyl-2,4-xylenol was found to be not mutagenic in Salmonella typhimurium TA100, TA98, TA1535, TA1537 and Escherichia coli WP2 uvrA, with and without metabolic activation.