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Toxicological information

Genetic toxicity: in vitro

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Administrative data

Endpoint:
in vitro gene mutation study in bacteria
Type of information:
experimental study
Adequacy of study:
key study
Study period:
10 December 1996 to 16 May 1997
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1997
Report Date:
1997

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 471 (Bacterial Reverse Mutation Assay)
Deviations:
no
GLP compliance:
yes
Type of assay:
bacterial reverse mutation assay

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
liquid
Details on test material:
CAS number: Not yet known
EC Number: Not yet known
Specific details on test material used for the study:
Description: Dark amber viscous liquid
Purity: 100%

Method

Species / strainopen allclose all
Species / strain / cell type:
S. typhimurium TA 1535, TA 1537, TA 98 and TA 100
Species / strain / cell type:
E. coli WP2 uvr A
Metabolic activation:
with and without
Metabolic activation system:
S9 Rat liver, induced with Aroclor
Test concentrations with justification for top dose:
Test 1 and Test 2: 0, 50, 150, 500, 1500 and 500 µg/plate.
5000 µg is the standard top dose recommended in the guidelines.
Vehicle / solvent:
Acetone
Controls
Positive controls:
yes
Positive control substance:
4-nitroquinoline-N-oxide
9-aminoacridine
N-ethyl-N-nitro-N-nitrosoguanidine
other: 2-Aminoanthracene

Results and discussion

Test resultsopen allclose all
Key result
Species / strain:
S. typhimurium, other: TA 100, A 1535, TA 1537 and TA 98
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
no cytotoxicity, but tested up to precipitating concentrations
Remarks:
1500 and 5000 µg/plate
Vehicle controls validity:
valid
Untreated negative controls validity:
valid
Positive controls validity:
valid
Key result
Species / strain:
E. coli WP2 uvr A
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
no cytotoxicity, but tested up to precipitating concentrations
Remarks:
1500 and 5000 µg/plate
Vehicle controls validity:
valid
Untreated negative controls validity:
valid
Positive controls validity:
valid

Applicant's summary and conclusion

Conclusions:
The test material was considered to be non-mutagenic under the test conditions of this test.
Executive summary:

Salmonella typhimurium strains TA 1535, TA 1537, TA98 and TA 100, and Escherichia coli strain WP2uvrA- were treated with the test material using the Ames plate incorporation method at five dose levels, 50, 150, 500, 1500, and 5000 ug/plate, in triplicate, both with and without the addition of a rat liver S9 metabolising system. The experiment was repeated on a separate day using the same dose range as experiment 1, fresh cultures of the bacterial strains, and fresh test material formulations.

The dose range was determined in a preliminary toxicity assay in which the test material at dose levels from 50 to 5000 µg/plate caused no visible reduction in the growth of the bacterial lawn at any dose level, either with or without metabolic activation.  A precipitate was observed at and above 1500 µg/plate, but did not interfere with the scoring of revertant colonies.

No significant increase in the frequency of revertant colonies was recorded for any of the bacterial strains with any dose of the test material, either with or without metabolic activation. The vehicle (acetone) control plates produced counts of revertant colonies within the normal range.  All of the positive control chemicals used in the test induced marked increases in the frequency of revertant colonies, both with and without the metabolising system. The test material was considered to be non-mutagenic under the conditions of this test.