Cyclohexyl phenyl ketone

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:

From Jun. 12, 2003 to Sep. 19, 2003

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Well documented, according to accepted guidelines.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2003

Report date:

2003

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

Version / remarks:

1997 followed, reliability scoring based on 1997 guideline.

Deviations:

yes

Remarks:

2-aminoanthracene was the only compound used to test the efficacy of the S9 fraction

GLP compliance:

yes (incl. QA statement)

Type of assay:

bacterial reverse mutation assay

Test material

Test material information

Constituent 1

Reference substance name:

Cyclohexyl phenyl ketone

EC Number:

211-923-5

EC Name:

Cyclohexyl phenyl ketone

Cas Number:

712-50-5

Molecular formula:

C13H16O

IUPAC Name:

cyclohexyl(phenyl)methanone

Details on test material:

- Name of test material (as cited in study report): TK A 40293
- Physical state: solid
- Analytical purity: 98%
- Lot/batch No.: CHPK 10/43-53
- Expiration date of the lot/batch: May 30, 2005
- Storage condition of test material: room temperature

Method

Species / strain

Species / strain 1

Species / strain / cell type:

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

Additional strain / cell type characteristics:

not applicable

Species / strain 2

Species / strain / cell type:

E. coli WP2 uvr A

Additional strain / cell type characteristics:

not applicable

Metabolic activation:

with and without

Metabolic activation system:

Phenobarbital/β-Naphthoflavone-induced rat liver S9

Test concentrations with justification for top dose:

Experiment I: 3, 10, 33, 100, 333, 1000, 2500 and 5000 µg/plate
Experiment II TA98 with and without S9 mix: 3, 10, 33, 100, 333 and 1000 µg/plate
Experiment II TA 1535 with and without S9 mix: 10, 33, 100, 333, 1000, 2500 and 5000 µg/plate
Experiment II TA 1537 and TA100 with and without S9 mix: 3, 10, 33, 100, 333, 1000 and 2500 µg/plate
Experiment II WP2 uvrA with and without S9 mix: 33, 100, 333, 1000, 2500 and 5000 µg/plate

Vehicle / solvent:

- Vehicle(s)/solvent(s) used: Dimethylsulfoxide (DMSO)
- Justification for choice of solvent/vehicle: The solvent was chosen because of its solubility properties and its relative non-toxicity to the bacteria.

Controls

Untreated negative controls:

yes

Remarks:

untreated

Negative solvent / vehicle controls:

yes

Remarks:

DMSO

True negative controls:

no

Positive controls:

yes

Positive control substance:

other: see Table 1

Details on test system and experimental conditions:

METHOD OF APPLICATION:
Experiment I: in agar (plate incorporation)
Experiment II: preincubation

DURATION
- Preincubation period: 60 minutes at 37°C
- Exposure duration: ≥48 hours at 37°C

NUMBER OF REPLICATIONS: 3 plates per test; two independent experiments performed.

Evaluation criteria:

-A test item is considered as a mutagen if a biologically relevant increase in the number of revertants exceeding the threshold of twice (strains TA 98, TA 100 and WP2 uvrA) or thrice (strains TA 1535 and TA 1537) the colony count of the corresponding solvent control is observed.
-A dose dependent increase is considered biologically relevant if the threshold is exceeded at more than one concentration.
-An increase exceeding the threshold at only one concentration is judged as biologically relevant if reproduced in an independent second experiment.
-A dose dependent increase in the number of revertant colonies below the threshold is regarded as an indication of a mutagenic potential if reproduced in an independent second experiment. However, whenever the colony counts remain within the historical range of negative and solvent controls such an increase is not considered biologically relevant.

Statistics:

Revertant colony numbers were calculated as average and standard deviation. No statistical analysis test was performed.

Results and discussion

Test results

Test results 1

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:

>100 µg/plate

Vehicle controls validity:

valid

Untreated negative controls validity:

not examined

Positive controls validity:

valid

Test results 2

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:

not examined

Positive controls validity:

valid

Remarks on result:

other: all strains/cell types tested

Remarks:

Migrated from field 'Test system'.

Any other information on results incl. tables

The plates incubated with the test item showed in Experiment I reduced background growth at 100 µg/plate and above with and without metabolic activation. In Experiment II reduced background growth were observed in strains TA 1535, TA 1537 and TA 100 at higher concentrations. Toxic effects, evident as a reduction in the number of revertants, occurred in all Salmonella strains with and without metabolic activation. No substantial increase in revertant colony numbers of any of the five tester strains was observed following treatment with TK A 40293 at any dose level, neither in the presence nor absence of metabolic activation (S9 mix).

Applicant's summary and conclusion

Conclusions:

Interpretation of results (migrated information):
negative with metabolic activation
negative without metabolic activation