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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:
1980/07/24-1980/12/08
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: This non-GLP study was conducted similar to OECD guideline and has significant deviations to warrant restriction. Study conducted on a read-across material

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1981
Report Date:
1981

Materials and methods

Test guideline
Qualifier:
equivalent or similar to
Guideline:
OECD Guideline 471 (Bacterial Reverse Mutation Assay)
Deviations:
yes
Remarks:
Only 4/5 recommended strains of bacteria tested and no information regarding cytotoxicity
GLP compliance:
no
Type of assay:
bacterial reverse mutation assay

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
Test material from lot EC24321 was described as brown or golden yellow, viscous liquid. The test article was stored in glass in the dark at room temperature.

Method

Target gene:
Point (reverse) mutations in selected histidine requiring mutant strains of Salmonella typhimurium. Tester strains have a deletion through uvrB to remove DNA excision repair function and rfa to remove the lipopolysaccharide coat. TA1535 is a missense mutant which is reverted by agents which cause base pair substitutions. TA98, TA1538, TA1537 are frame shift mutants. TA98 is TA1538 and TA100 is TA1535 with the additions of pKM101 plasmid.
Species / strainopen allclose all
Species / strain / cell type:
S. typhimurium TA 1535, TA 1537, TA 98 and TA 100
Species / strain / cell type:
S. typhimurium TA 1538
Metabolic activation:
with and without
Metabolic activation system:
S9
Test concentrations with justification for top dose:
1.0, 0.3, 0.1, 0.03 and 0.01 ul/plate
Vehicle / solvent:
All dilutions were made with ethyl acetate due to solubility and lack of reactivity with test article.
Controlsopen allclose all
Positive controls:
yes
Positive control substance:
9-aminoacridine
Remarks:
TA 1537 -S9

Migrated to IUCLID6: 10 ug/plate
Positive controls:
yes
Positive control substance:
2-nitrofluorene
Remarks:
TA 98 and TA 1538 -S9

Migrated to IUCLID6: 5 ug/plate
Untreated negative controls:
yes
Remarks:
bacteria only
Negative solvent / vehicle controls:
yes
Remarks:
ethyl acetate
Positive controls:
yes
Positive control substance:
other: 2-Aminoanthracene 5 ug/plate
Remarks:
For all strains +S9
Details on test system and experimental conditions:
The assay was performed by plate incorporation and the method of Ames et al with modification. The assay was performed in duplicate, with (+S9) or without (-S9) metabolic activation. Each of the tester strains was dosed with 5 concentrations of test substance, solvent controls, and a positive control. Three plates/dose group/strain/treatment set were evaluated. 100 ul of test substance, positive control or vehicle control were added to each plate along with 100 ul of tester strain, S9 mix (if required) and 2.0 ml of molten top agar. This was overlaid onto the surface of bottom agar in a petri dish and plates were incubated for 48 h at 37 C. The number of revertant colonies were counted on a Biotran II automatic colony counter.
Evaluation criteria:
All sterility controls must be negative for bacterial growth. The average number of revertant colonies representing spontaneous mutation must be within the following acceptable range: TA1535, 6-60; TA1537, 3-16; TA1538, 6-35; TA100, 80-250; TA98, 10-60. The average number of revertant colonies in the positive control plates must be at least 5 times those of the solvent control.

Statistics:
Mean revertant colony count and standard deciation were calculated for each dose level and compared to solvent controls.

Results and discussion

Test resultsopen allclose all
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:
not specified
Vehicle controls validity:
valid
Untreated negative controls validity:
valid
Positive controls validity:
valid
Species / strain:
S. typhimurium TA 1538
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
not specified
Vehicle controls validity:
valid
Untreated negative controls validity:
valid
Positive controls validity:
valid
Additional information on results:
A range finder was not included in this report.
Remarks on result:
other: all strains/cell types tested
Remarks:
Migrated from field 'Test system'.

Applicant's summary and conclusion

Conclusions:
Interpretation of results (migrated information):
negative

No detectable mutagenic activity for this test substance was found under the conditions of this study.
Executive summary:

In a bacterial reverse mutation assay in the presence and absence of exogenous metabolic activation, Salmonella strains TA1535, TA1537, TA1538, TA98, and TA100 were treated with test substance at concentrations of 0.03, 0.01, 0.006, 0.003, 0.001 ul/plate. The negative and positive controls fulfilled the requirements for determination of a valid test. None of the test substance treatment conditions produced a statistically significant increase in the number of revertants. Based on the results of this study, the test substance would not be classified based on weight of evidence for the chemical class in accordance with the classification system of GHS.

This toxicity study is classified as acceptable and satisfies the guideline requirement for in vitro mutagenicity test.