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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:
migrated information: read-across from supporting substance (structural analogue or surrogate)
Adequacy of study:
key study
Study period:
2002
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: GLP guideline study, OECD guideline conform, well documented, read across substance

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2002
Report Date:
2002

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 471 (Bacterial Reverse Mutation Assay)
GLP compliance:
yes (incl. certificate)
Type of assay:
bacterial reverse mutation assay

Test material

Reference
Name:
Unnamed
Type:
Constituent

Method

Target gene:
His-: Salmonella typhimurium
Trp-: E. coli
Species / strain
Species / strain / cell type:
other: TA 1537, TA 98, TA1535, TA100, WP2 uvrA
Metabolic activation:
with and without
Metabolic activation system:
Phenobarbital/p-Naphthoflavone induced rat liver S9 mix
Test concentrations with justification for top dose:
Experiment I (plate incorporation test): 33; 100; 333; 1000; 2500; and 5000 µg/plate
Experiment II (preincubation test): 10; 33; 100; 333; 1000; 2500; and 5000 µg/plate
Vehicle / solvent:
DMSO
Controls
Untreated negative controls:
yes
Negative solvent / vehicle controls:
yes
True negative controls:
yes
Positive controls:
yes
Positive control substance:
other: see: "Details on test system"
Details on test system and experimental conditions:
Positive Control Substances:
Without metabolic activation:
Strains: TA 1535, TA 100
Name: sodium azide, NaN3
Supplier: SERVA, D-69042 Heidelberg
Catalogue No.: 30175
Purity: at least 99 %
Dissolved in: water deionised
Concentration: 10 µg/plate

Strains: TA1537,TA98
Name: 4-nitro-o-phenylene-diamine, 4-NOPD
Supplier: SIGMA. D-82041 Deisenhofen
Catalogue No.: N9504
Purity: > 99.9 %
Dissolved in: DMSO (MERCK. D-64293 Darmstadt; purity > 99 %)
Concentration: 10 µg/plate in TA 98. 50 µg/plate in TA 1537

Strains: WP2 uvrA
Name: methyl methane sulfonate. MMS
Supplier: Merck-Schuchardt, D-85662 Hohenbrunn
Catalogue No.: 820775
Purity: > 99.0 %
Dissolved in: water deionised
Concentration: 4 µl/plate

With metabolic activation:
Strains: TA 1535, TA 1537, TA 98. TA 100, WP2 uvrA
Name: 2-aminoanthracene, 2-AA
Supplier: SIGMA, D-82041 Deisenhofen
Catalogue No.: A 1381
Purity: 97.5 %
Dissolved in: DMSO (MERCK, D-64293 Darmstadt; purity > 99 %)
Concentration: 2.5 µg/plate, 10 µg/plate in strain WP2 uvrA
Evaluation criteria:
The Salmonella typhimurium and Escherichia coli reverse mutation assay is considered acceptable if it meets the following criteria:
- regular background growth in the negative and solvent control
- the spontaneous reversion rates in the negative and solvent control are in the range of our historical data
- the positive control substances should produce a significant increase in mutant colony frequencies

A test item is considered as a mutagen if a biologically relevant increase in the number of revertants exceeding the threshold of twice (strains TA 98, TA 100, and WP2 uvrA) or thrice (strains TA 1535 and TA 1537) the colony count ofthe corresponding solvent control is observed.
A dose dependent increase is considered biologically relevant if the threshold is exceeded at more than one concentration.
An increase exceeding the threshold at only one concentration is judged as biologically relevant if reproduced in an independent second experiment
A dose dependent increase in the number of revertant colonies below the threshold is regarded as an indication of a mutagenic potential if reproduced in an independent second experiment. However, whenever the colony counts remain within the historical range of negative and solvent controls such an increase is not considered biologically relevant.
Statistics:
No statistical evaluation of the data is required.

Results and discussion

Test results
Species / strain:
other: Salmonella typhimurium strains TA 1535, TA 1537, TA98, and TA 100, and the Escherichia coli strain WP2 uvrA.
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
cytotoxicity
Remarks:
see: "Additional information on results"
Vehicle controls validity:
valid
Untreated negative controls validity:
valid
Positive controls validity:
valid
Additional information on results:
In experiment I: toxic effects (below the factor of 0.5) were observed at higher concentrations in strain TA 1535 without S9 mix and in strains TA 1537 and TA 98 with and without S9 mix.
In experiment II: toxic effects were observed at the two highest concentrations in strain TA 1535 without S9 mix.
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