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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:
oct - nov 1985
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
guideline study with acceptable restrictions

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1985
Report Date:
1985

Materials and methods

Test guideline
Qualifier:
equivalent or similar to
Guideline:
OECD Guideline 471 (Bacterial Reverse Mutation Assay)
GLP compliance:
yes
Type of assay:
bacterial reverse mutation assay

Test material

Reference
Name:
Unnamed
Type:
Constituent

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:
S9 mix from Aroclor induced rat liver and S9 mix from hamster supplemented with flavin mononucleotid
Test concentrations with justification for top dose:
0, 4, 20, 100, 500, 2500, 5000 microgramm/plate
Vehicle / solvent:
- Vehicle(s)/solvent(s) used: DMS
Controls
Negative solvent / vehicle controls:
yes
Positive controls:
yes
Positive control substance:
9-aminoacridine
2-nitrofluorene
sodium azide
benzo(a)pyrene
congo red
other: 2-Aminoanthracene (TA 98, TA 100, TA 1535, TA 1537, with S9 mix), 2-Aminoanthracene (Prival-Test: TA 100, TA 1535, TA 1537, with S9 mix), Benzidine (Prival-Test: TA 98, with S9 mix)
Details on test system and experimental conditions:
METHOD OF APPLICATION: in agar (plate incorporation), preincubation (prival test)

DURATION
- Preincubation period: 30 min
- Exposure duration: 48-72 h

NUMBER OF REPLICATIONS: 2 independent experiments of each protocol

NUMBER OF CELLS EVALUATED: all colonies (his+ revertants) were counted

DETERMINATION OF CYTOTOXICITY
- Method: relative total growth

Results and discussion

Test results
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, but tested up to precipitating concentrations
Vehicle controls validity:
valid
Positive controls validity:
valid
Additional information on results:
RANGE-FINDING/SCREENING STUDIES:
Preliminary toxicity tests were performed with all tester strains using two plates per dose to get information on mutagenicity and toxicity for calculation of an appropriate dose range. A reduced rate of spontaneously occuring colonies as well as visible thinning of the bacterial lawn were used as indicator for toxicity. Thinning of the bacterial lawn was controlled microscopically.

Applicant's summary and conclusion

Conclusions:
Interpretation of results:
negative

It is concluded the the test substance is not mutagenic in the absence and presence of rat S-9 Mix using the standard Ames Test procedure. Also in the preincubation method to Prival the test compound is not mutagenic in the presence of hamster liver S-9.