2,6,6-trimethylcyclohex-2-ene-1,4-dione

Genetic toxicity: in vitro

Administrative data

Endpoint:

in vitro gene mutation study in bacteria

Remarks:

Type of genotoxicity: genome mutation

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1997

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: According to OECD 471, 472 and EEC Directives 92/69, B 13 and 14. Study conducted under GLP.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1997

Report date:

1997

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

Test guideline 2

Qualifier:

according to guideline

Guideline:

OECD Guideline 472 (Genetic Toxicology: Escherichia coli, Reverse Mutation Assay)

Test guideline 3

Qualifier:

according to guideline

Guideline:

EU Method B.13/14 (Mutagenicity - Reverse Mutation Test Using Bacteria)

GLP compliance:

yes

Type of assay:

bacterial reverse mutation assay

Test material

Test material information

Constituent 1

Reference substance name:

2,6,6-trimethylcyclohex-2-ene-1,4-dione

EC Number:

214-406-2

EC Name:

2,6,6-trimethylcyclohex-2-ene-1,4-dione

Cas Number:

1125-21-9

Molecular formula:

C9H12O2

IUPAC Name:

2,6,6-trimethylcyclohex-2-ene-1,4-dione

Constituent 2

Reference substance name:

Oxoisophoron

IUPAC Name:

Oxoisophoron

Details on test material:

- Name of test substance: Oxoisophoron
- Batch No.: not given
- CAS No.: 1125-21-9
- Date of manufacture: May 18, 1995
- Test substance No.: 96/87
- Degree of purity: 98.87%
- Appearance, consistency: Yellowish liquid
- Storage: Room temperature

Method

Target gene:

his, trp

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:

Male Sprague-Dawley rat liver S-9 fraction. Induction with Aroclor 1254.

Test concentrations with justification for top dose:

20; 100; 500; 2,500 and 5,000 µg/plate

Vehicle / solvent:

DMSO

Controls

Untreated negative controls:

yes

Remarks:

vehicle control and sterility control

Negative solvent / vehicle controls:

yes

True negative controls:

no

Positive controls:

yes

Positive control substance:

other: 2-aminoanthracene (2-AA): 2.5 and 60 µg with S-9; N-methyl-N'-nitro-o-phenylendiamine: 5 µg without S-9; 4-nitro-o-phenylendiamine (NOPD): 10 µg without S-9; 9-aminoacridine: 100 µg without S-9; N-ethyl-N'-nitro-N-nitrosoguanidine: 10 µg without S-9.

Details on test system and experimental conditions:

Test conducted according to the Ames procedure (standard plate test and preincubation test, with and without S9-Mix).

Number of plates: 3 test plates per dose or per control.

Vehicle: DMSO

The study comprised 2 independent experiments.

1st Experiment:
Strains: TA 1535, TA 100, TA 1537, TA 98, E. coli WP2 uvrA.
Doses: 0; 20; 100; 500; 2500 and 5000 ug/plate.
Vehicle: DMSO.
Type of test and test conditions: standard plate test with and without S9-Mix.
Number of plates: 3 test plates per dose or per control.

2nd Experiment:
Strains: TA 1535, TA 100, TA 1537, TA 98, E. coli WP2 uvrA.
Doses: 0; 20; 100; 500; 2500 and 5000 ug/plate.
Vehicle: DMSO.
Type of test and test condition: preincubation test with and without S9 mix.
Number of plates: 3 test plates per dose or per control.

Evaluation criteria:

In general, a substance to be characterized as positive in the bacterial tests has to fulfil the following requirements:
- doubling of the spontaneous mutation rate (control)
- dose-response relationship
- reproducibility of the results.

Results and discussion

Test results

Test results 1

Species / strain:

E. coli WP2 uvr A

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

Positive controls validity:

valid

Test results 2

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:

other: A slight decrease in the nunber of his* revertants was occasionally observed. A reduced his- background growth was found using TA 98 in the preincubation test without S-9 mix at 5,000 µg/plate.

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

Positive controls validity:

valid

Remarks on result:

other: all strains/cell types tested

Remarks:

Migrated from field 'Test system'.

Applicant's summary and conclusion

Conclusions:

According to the results of the present study, oxoisophoron is not mutagenic in the Ames test and in the Escherichia coli - reverse mutation assay under the chosen experimental conditions. Thus, no classification is warranted according to Regulation (EC) No. 1272/2008 and EU Directive 67/548/EEC.