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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:
17 October 1980
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
comparable to guideline study with acceptable restrictions
Remarks:
Study conducted similarly to OECD 471 Guideline with deviations: purity of test substance; evaluation criteria not reported ; E. Coli strain not tested

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1980
Report Date:
1980

Materials and methods

Test guideline
Qualifier:
equivalent or similar to
Guideline:
OECD Guideline 471 (Bacterial Reverse Mutation Assay)
Deviations:
yes
Remarks:
purity of test substance; evaluation criteria not reported ; E. Coli strain not tested
Principles of method if other than guideline:
Not applicable
GLP compliance:
no
Remarks:
pre-GLP
Type of assay:
bacterial reverse mutation assay

Test material

Reference
Name:
Unnamed
Type:
Constituent
Type:
Constituent
Test material form:
solid
Remarks:
white waxy solid
Specific details on test material used for the study:
SOURCE OF TEST MATERIAL
- Date of receipt: 26 August 1980

Method

Target gene:
histidine
Species / strain
Species / strain / cell type:
S. typhimurium, other: TA 1535, TA 1537, TA 1538, TA 98 and TA 100
Details on mammalian cell type (if applicable):
not applicable
Additional strain / cell type characteristics:
not applicable
Metabolic activation:
with and without
Metabolic activation system:
S9 fraction was prepared from liver homogenates of male Wistar rats induced with Aroclor 1254
Test concentrations with justification for top dose:
0.06, 0.19, 0.56, 1.67 and 5.0 mg/ 0.1 ml H2O/ plate, with and without metabolic activation
Vehicle / solvent:
- Vehicle(s)/solvent(s) used: Distilled water
- Appropriate solutions of the test material were prepared in glass distilled water immediately before use.
Controlsopen allclose all
Untreated negative controls:
no
Negative solvent / vehicle controls:
yes
Remarks:
distilled water
True negative controls:
no
Positive controls:
yes
Positive control substance:
sodium azide
other: hycanthone methanesulphonate
Remarks:
without metabolic activation
Untreated negative controls:
no
Negative solvent / vehicle controls:
yes
Remarks:
distilled water
True negative controls:
no
Positive controls:
yes
Positive control substance:
other: 2-aminoanthracene
Remarks:
with metabolic activation
Details on test system and experimental conditions:
SOURCE OF TEST SYSTEM
- Salmonella typhimurium mutants used viz. S. typhimurium TA 1535, TA 1537, TA 1538, TA 98 and TA 100 were provided by Dr. B.N. Ames, Berkeley, California, USA.

METHOD OF APPLICATION: in agar (plate incorporation)

DURATION
- Exposure duration: 37 °C for 3 days

NUMBER OF REPLICATIONS:
3 plates/dose

DETERMINATION OF CYTOTOXICITY
- Method: Toxicity was evaluated by background lawn of bacterial growth.

OTHER:
- Colonies (revertants which are histidine independent) were counted and the background lawn of bacterial growth was examined microscopically.
- S9, S9 mix and test product was checked for sterility.
Rationale for test conditions:
The dose range used in the mutagenesis assay was based on a preliminary test performed to assess the toxicity of the compound for the bacteria.
Evaluation criteria:
No data
Statistics:
None

Results and discussion

Test results
Key result
Species / strain:
S. typhimurium, other: TA 1535, TA 1537, TA 1538, TA 98 and TA 100
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
no cytotoxicity
Vehicle controls validity:
valid
Untreated negative controls validity:
not applicable
Positive controls validity:
valid
Additional information on results:
TEST-SPECIFIC CONFOUNDING FACTORS
- Water solubility: The dose levels used in the study were based on the solubility of the test substance in water: 5 % (w/v) was soluble, while 10 % was not soluble.

CYTOTOXICITY:
There were no signs that chemical toxicity interfered with the mutagenicity testing; the background lawn of bacterial growth in control and test plates was comparable.

MUTAGENICITY
- Test substance up to 5 mg/plate did not increase the numbers of his+ revertants with any of the five tester strains, either in the presence or in the absence of S9 mix.

Any other information on results incl. tables

See "Attached background material" section for table of results

Applicant's summary and conclusion

Conclusions:
Under the test conditions, test substance is not considered as mutagenic in S. typhimurium (TA 1535, TA 1537, TA 1538, TA 98 and TA 100) strains.
Executive summary:

In a reverse gene mutation assay in bacteria, performed similarly to the OECD Guideline 471, strains of Salmonella typhimurium (TA 1535, TA 1537, TA 1538, TA 98 and TA 100) were exposed to test substance at the following concentrations using plate incorporation method: 0.06, 0.19, 0.56, 1.67 and 5.0 mg/plate, with and without metabolic activation

 

S9 fraction prepared from liver homogenates of male Wistar rats induced with Aroclor 1254. Vehicle and positive control groups were also included in mutagenicity tests.

 

No evidence of toxicity was observed up to 5.0 mg/plate with or without metabolic activation and the background lawn of bacterial growth in control and test plates was comparable. No significant increases in the frequency of revertant colonies were recorded for any of the bacterial strains, at any dose level either with or without metabolic activation. 

 

Under the test conditions, test substance is not considered as mutagenic in this bacterial system.