Registration Dossier

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
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Study conducted as part of the USA National Toxicology Program.

Data source

Reference
Reference Type:
publication
Title:
Unnamed
Year:
1991

Materials and methods

Test guideline
Qualifier:
equivalent or similar to
Guideline:
OECD Guideline 471 (Bacterial Reverse Mutation Assay)
Deviations:
yes
Remarks:
Minor
Principles of method if other than guideline:
Essentially OECD 471
GLP compliance:
not specified
Type of assay:
bacterial reverse mutation assay

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
Not specified

Method

Species / strain
Species / strain:
S. typhimurium TA 1535, TA 1537, TA 98 and TA 100
Additional strain characteristics:
not specified
Metabolic activation:
with and without
Metabolic activation system:
Aroclor 1254-induced Sprague-Dawley rat or Syrian hamster liver
Test concentrations with justification for top dose:
5 concentrations, up to limit of toxicity/solubility (did not exceed 3,333 mcg/plate)
Vehicle:
Buffer or S9 mix
Details on test system and conditions:
Incubation for 20 minutes at 37 degC prior to the addition of soft agar supplemented with l-histidine and d-biotin. Subsequent plating on minimal
glucose plates. Incubation continued for an additional 48 hours.
Each test consisted of triplicate plates of concurrent positive and negative controls and at least 5 concentrations of test material.
Evaluation criteria:
Positive response defined as a reproducible, dose-related increase in histidine-dependent (revertant) colonies in any one strain/activation
combination. An equivocal response defined as an increase in revertants which was not dose-related, not reproducible, or of insufficient magnitude to support a determination of mutagenicity. Negative response obtained when no increase in revertant colonies was observed following treatment.
Statistics:
Not specified

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:
yes
Vehicle controls valid:
not specified
Negative controls valid:
not specified
Positive controls valid:
not specified
Remarks on result:
other: all strains/cell types tested
Remarks:
Migrated from field 'Test system'.

Applicant's summary and conclusion

Conclusions:
Negative in the reverse mutation assay in vitro when tested in Salmonella typhimurium strains TA100, TA1535, TA1537 and TA98 in a preincubation protocol, with and without metabolic activation.