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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:
From December 07, 1994 to December 16, 1994
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
comparable to guideline study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1995
Report Date:
1995

Materials and methods

Test guideline
Qualifier:
equivalent or similar to
Guideline:
OECD Guideline 471 (Bacterial Reverse Mutation Assay)
Deviations:
no
GLP compliance:
yes (incl. certificate)
Type of assay:
bacterial reverse mutation assay

Test material

Reference
Name:
Unnamed
Type:
Constituent
Specific details on test material used for the study:
- Code: 06 FHFR 555
- Batch no.: E06 1859561, dated May 31, 1994
- Purity: 79.8% (w/v)
- Stability and homogeneity: Stable for 4 h
- Storage condition: Dark at approximately 20⁰C
- Appearence: White to yellowish scales
- pH (in water): 5.1

Method

Species / strain
Species / strain:
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:
0.8, 4, 20, 100, 500 and 2,500 µg/plate (for both with and without metabolic activation)
Vehicle:
Ethanol
Controlsopen allclose all
Negative controls:
yes
Solvent controls:
yes
Positive controls:
yes
Positive control substance:
sodium azide
Remarks:
Tested for TA 100, TA 1535 in the absence of S9-mix
Negative controls:
yes
Solvent controls:
yes
Positive controls:
yes
Positive control substance:
9-aminoacridine
Remarks:
Tested for TA 1537 in the absence of S9-mix
Negative controls:
yes
Solvent controls:
yes
Positive controls:
yes
Positive control substance:
2-nitrofluorene
Remarks:
Tested for TA 98 in the absence of S9-mix
Negative controls:
yes
Solvent controls:
yes
Positive controls:
yes
Positive control substance:
other: 2-amino anthracene
Remarks:
Tested for TA 100, TA 1535, TA 1537, TA 98 in presence of S9-mix
Details on test system and conditions:
METHOD OF APPLICATION: In agar (plate incorporation)
DURATION:
- Preincubation period: 48h

Evaluation criteria:
The test substance is classified as mutagenic if it has either of the following effects:
- 2-fold increase in the mean number of revertants per plate of at least one of the tester strains over the mean number of revertants per plate of the appropriate vehicle control at complete bacterial background lawn.
- Dose related increase in the mean number of revertants per plate of atleast one of the tester strains over the mean number of revertants per plate of the appropriate vehicle control in atleast two to three concentration of the test substance at complete bacterial background lawn.

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:
yes
Vehicle controls valid:
yes
Negative controls valid:
yes
Positive controls valid:
yes
Additional information on results:
Solubility: Visible precipitation of the test substance on the plates was observed at 5,000 µg/plate in the first experiment.
Toxicity: The test substance was toxic to most of the bacterial strain at doses of 100 µg/plate and above. Thinning of the bacterial lawn and a reduction in the number of colonies were observed at this dose.

Applicant's summary and conclusion

Conclusions:
Under the study conditions, the test substance was not mutagenic in Salmonella typhimurium strain TA97, TA98, TA100 or TA1535, with or without metabolic activation.
Executive summary:

A study was conducted to determine the in vitro genetic toxicity of the test substance according to a method similar to OECD Guideline 471, in compliance with GLP. Salmonella typhimurium strains TA97, TA98, TA100 and TA1535 were treated with the test substance using the Ames plate incorporation method. Tests were carried out in triplicate, both with and without the addition ofmetabolic activation (S9-mix). The concentration range of the test substance was 0.8 to 2,500 µg/plate. Cytotoxicity was observed at ≥100 µg/plate. No significant increase in the frequency of revertant colonies was recorded for any of the bacterial strains at any of the test substance concentrations tested, either with or without metabolic activation. Under the study conditions, the test substance was not mutagenic in Salmonella typhimurium strain TA97, TA98, TA100 or TA1535, with or without metabolic activation (Muller, 1995).