4-methylbenzophenone

Genetic toxicity: in vitro

Administrative data

Endpoint:

in vitro gene mutation study in bacteria

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1985

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

comparable to guideline study with acceptable restrictions

Data source

Reference

Reference Type:

publication

Title:

Unnamed

Year:

1986

Report date:

1986

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

Deviations:

yes

Remarks:

Test with strains TA98, TA100, TA 1535 and TA 1537

GLP compliance:

not specified

Type of assay:

bacterial reverse mutation assay

Test material

Test material information

Constituent 1

Reference substance name:

Benzophenone

EC Number:

204-337-6

EC Name:

Benzophenone

Cas Number:

119-61-9

Molecular formula:

C13H10O

IUPAC Name:

benzophenone

Details on test material:

- Name of test material (as cited in study report): Benzophenone
- Supplier: Aldrich
- Analytical purity: 99%

Method

Species / strain

Species / strain / cell type:

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

Metabolic activation:

with and without

Metabolic activation system:

S9 mix

Test concentrations with justification for top dose:

0 - 1000 ug/plate

Vehicle / solvent:

DMSO

Controls

Untreated negative controls:

yes

Negative solvent / vehicle controls:

yes

True negative controls:

no

Positive controls:

yes

Positive control substance:

other: sodium azide, 4-nitro-o-phenylenediamine, 9-aminoacridine and 2-aminoanthracene

Details on test system and experimental conditions:

Testing comparable to guideline

Evaluation criteria:

mutagenic response: dose-related, reproducible increase in the number of revertants over background, even if the increase was less than twofold
nonmutagenic response: no increase in the number of revertants
questionable response: absence of a clear-cut dose-related increase in revertants, dose-related increases in the number of revertants not reproducible or response was of insufficient magnitude to support a determination of mutagenicity

Statistics:

not further specified

Results and discussion

Test results

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:

no cytotoxicity

Remarks:

tested up to precipitating concentrations

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

Positive controls validity:

valid

Additional information on results:

RANGE-FINDING/SCREENING STUDIES: Benzophenone was tested initially with tester strain TA100 in the presence and absence of the metabolic activation system, over a wide dose range with an upper limit of 10 mg/plate, or less when solubility problems were encountered. A concentration of 1000 µg/plate was slightly toxic and was therefore selected as highest dose.

Any other information on results incl. tables

See attached documents

Applicant's summary and conclusion

Conclusions:

Benzophenone did not significatly increase the number of revertant colonies both in the absence or presence of a metabolic system and is therefore considered non-mutagenic in this test system.

Executive summary:

Benzophenone was tested in the Salmonella pre-incubation assay, which was performed in duplicate with and without metabolic activation. Concurrent positive control substances confirmed the sensitivity of the test system.

Benzophenone did not induce mutations in S. typhimurium strains in any of the concentrations tested and is therefore considered non-mutagenic in this test system.