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Toxicological information

Genetic toxicity: in vitro

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Administrative data

Endpoint:
in vitro gene mutation study in bacteria
Remarks:
Type of genotoxicity: gene mutation
Type of information:
experimental study
Adequacy of study:
key study
Study period:
Nov 13 - Dec 04, 1992
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1993
Report Date:
1993

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 471 (Bacterial Reverse Mutation Assay)
Principles of method if other than guideline:
none
GLP compliance:
yes (incl. certificate)
Type of assay:
bacterial reverse mutation assay

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
solid

Method

Target gene:
His operon (Salmonella), Trp operon (E. coli)
Species / strain
Species / strain:
S. typhimurium TA 1535, TA 1537, TA 98, TA 100 and E. coli WP2
Metabolic activation:
with and without
Metabolic activation system:
liver S9 mix from PB/NF-pretreated rats
Test concentrations with justification for top dose:
1st series: 10, 50, 100, 500, 1000, 5000 µg/plate
2nd series: 313, 625, 1250, 2500, 5000 µg/plate
Vehicle:
DMSO
Purity > 99 %
Controls
Negative controls:
yes
Solvent controls:
yes
Positive controls:
yes
Positive control substance:
2-acetylaminofluorene
9-aminoacridine
sodium azide
benzo(a)pyrene
other: 2-Aminoanthracene
Details on test system and conditions:
METHOD OF APPLICATION: in agar (plate incorporation)

DURATION
- Preincubation period: no
- Exposure duration: 48-52 hours

NUMBER OF REPLICATIONS: 2


DETERMINATION OF CYTOTOXICITY
- Method: other: background clearance

OTHER EXAMINATIONS:
- Determination of polyploidy: na
- Determination of endoreplication: na
- Other:

Evaluation criteria:
A test material is defined as non-mutagenic in this assay if
• "no" or "weak increases" occur in the first and second series of the main experiment. ("Weak increases" randomly occur due to experimental variation.)

A test material is defined as mutagenic in this assay if
• a dose-related (over at least two test material concentrations) increase in the number of revertants is induced, the maximal effect is a "clear increase", and the effects are reproduced at similar concentration levels in the same test system;
• "clear increases" occur at least at one test material concentration, higher concentrations show strong precipitation or cytotoxicity, and the effects are reproduced at the same concentration level in the same test system.
Statistics:
no

Results and discussion

Test results
Key result
Species / strain:
S. typhimurium TA 1535, TA 1537, TA 98, TA 100 and E. coli WP2
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity:
no, but tested up to precipitating concentrations
Vehicle controls valid:
yes
Negative controls valid:
yes
Positive controls valid:
yes
Remarks on result:
other:
Additional information on results:
precipitation @50 µg/plate from beginning until end of experiment

Applicant's summary and conclusion

Conclusions:
With and without addition of S9 mix as the external metabolizing system, the test material was not mutagenic under the experimental conditions described.