Clorofene

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:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: peer reviewed data

Data source

Reference

Reference Type:

publication

Title:

Unnamed

Year:

1986

Report date:

1985

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

Version / remarks:

adopted in 1997

Deviations:

yes

Remarks:

no 5th strain (TA 102 or E.coli) was tested

GLP compliance:

no

Type of assay:

bacterial reverse mutation assay

Test material

Test material information

Constituent 1

Reference substance name:

Clorofene

EC Number:

204-385-8

EC Name:

Clorofene

Cas Number:

120-32-1

Molecular formula:

C13H11ClO

IUPAC Name:

clorofene

Method

Target gene:

his

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:

cofactor supplemented post-mitochondrial fraction (S9 mix) from livers of Aroclor-1254-treated male Sprague-Dawley rat or Syrian hamster liver

Test concentrations with justification for top dose:

0.1, 0.3, 1.0, 3.0, 10.0, 33.0, 66.0, 100.0 µg/plate with and without metabolic activation

Vehicle / solvent:

not specified

Controls

Untreated negative controls:

no

Negative solvent / vehicle controls:

yes

True negative controls:

no

Positive controls:

yes

Positive control substance:

9-aminoacridine

sodium azide

other: 2-aminoanthracene (2-AA), 4-nitro-1,2-phenylene diamine (4-NOPD)

Details on test system and experimental conditions:

METHOD OF APPLICATION: preincubation

DURATION
- Preincubation period: 20 min
- Exposure duration: 48 h

NUMBER OF REPLICATIONS: 3 replications each in 2 independent experiments

DETERMINATION OF CYTOTOXICITY
- Method: cloning efficiency, other: thinning, absence of bacterial lawn, appearance of his(-) pinpoint colonies

Evaluation criteria:

The criteria used for data evaluation are summarized as follows: 1) mutagenic response: a dose-delated, reproducible increase in the number of revertants over background, even if the increase was less than twofold; 2) nonmutagenic response: when no increase in the number of revertants was elicited by the chemical; 3) questionable response: when there was an absence of a clear-cut dose-related increase in revertants; when the dose-related increases in the number of revertants were not reproducible; or when the response was of insufficient magnitude to support a determination of mutagenicity. The initial determination of mutagenic, nonmutagenic, or equivocal was made by the testing laboratory; the final determination was made by the project officer.

Statistics:

Mean values and standard deviation were calculated.

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:

cytotoxicity

Remarks:

slight toxicity at 100 µg/plate with metabolic activation

Vehicle controls validity:

valid

Untreated negative controls validity:

not examined

Positive controls validity:

valid

Test results 2

Species / strain:

S. typhimurium TA 1537

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

cytotoxicity

Remarks:

slight toxicity at 100 µg/plate with metabolic activation

Vehicle controls validity:

valid

Untreated negative controls validity:

not examined

Positive controls validity:

valid

Test results 3

Species / strain:

S. typhimurium TA 98

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

cytotoxicity

Remarks:

slight toxicity at 33 µg/plate with and without metabolic activation

Vehicle controls validity:

valid

Untreated negative controls validity:

not examined

Positive controls validity:

valid

Test results 4

Species / strain:

S. typhimurium TA 100

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

cytotoxicity

Remarks:

(slight) toxicity at 33 µg/plate with metabolic activation

Vehicle controls validity:

valid

Untreated negative controls validity:

not examined

Positive controls validity:

valid

Additional information on results:

RANGE-FINDING/SCREENING STUDIES:
The test substance was initially tested with strain TA 100 in the presence and the absence of the metabolic activation systems, over a wide dose range with an upper limit of 10 mg/plate, or less when solubility problems were encountered. Toxicity was evidenced by one or more of the following phenomena: appearance of his - pinpoint colonies, reduced numbers of revertant colonies per plate, or thinning or absence of the bactenal lawn. As a rule, at least one toxic dose was incorporated into the first mutagenicity test; the repeat test occasionally had the doses adjusted so that an apparent toxic dose was not reached.

Any other information on results incl. tables

Please refer to the results provided under "Attached background material".