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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:
1992
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: GLP guideline study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Report Date:
1992

Materials and methods

Test guidelineopen allclose all
Qualifier:
according to
Guideline:
OECD Guideline 471 (Bacterial Reverse Mutation Assay)
Qualifier:
according to
Guideline:
OECD Guideline 472 (Genetic Toxicology: Escherichia coli, Reverse Mutation Assay)
Qualifier:
according to
Guideline:
EU Method B.13/14 (Mutagenicity - Reverse Mutation Test Using Bacteria)
GLP compliance:
yes
Type of assay:
bacterial reverse mutation assay

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
- Name of test material (as cited in study report): Laromer LR8869
- Physical state: nearly colorless liquid
- Analytical purity: >99%
- Lot/batch No.: 22386/142
- Stability under test conditions: verified analytically
- Storage condition of test material: +4 - +6°C

Method

Target gene:
his (salmonella)
trp (e.coli)
Species / strain
Species / strain / cell type:
S. typhimurium TA 1535, TA 1537, TA 98, TA 100 and E. coli WP2
Additional strain / cell type characteristics:
other: periodically checked for deep rough character, UV sensitivity, and ampicillin resistance
Metabolic activation:
with and without
Metabolic activation system:
arcolor induced S9 mix
Test concentrations with justification for top dose:
0, 20, 100, 500, 2500, 5000µg/plate
Vehicle / solvent:
- Vehicle(s)/solvent(s) used: DMSO
Controlsopen allclose all
Untreated negative controls:
no
Negative solvent / vehicle controls:
yes
True negative controls:
no
Positive controls:
yes
Positive control substance:
other: 2-aminoanthracene
Remarks:
with s9
Untreated negative controls:
no
Negative solvent / vehicle controls:
yes
True negative controls:
no
Positive controls:
yes
Positive control substance:
other: N-methyl-N-nitro-N-nitroso-guanidine (TA100 + TA1535); 4-nitro-o-phenylendiamin (TA98); 9-aminoacridine (TA1537); N-ethyl-N-nitro-N-nitroso-guanidin (e.coli WP2)
Remarks:
without S9
Details on test system and experimental conditions:
METHOD OF APPLICATION: in agar (plate incorporation) and preincubation;

DURATION
- Preincubation period: none (standard test); 20min (pre-incubation experiment)
- Exposure duration: 48h

SELECTION AGENT (mutation assays): histidine (salmonella), tryptophane (e.coli)

NUMBER OF REPLICATIONS: 3

DETERMINATION OF CYTOTOXICITY
- Method: titer determination of parallel cultures grown in agar containing maximal amino acid solution (control and two highest concentrations)
Evaluation criteria:
In general, a substance to be characterized as positive in the bacterjal tests has to fulfill the following requirements:
- doubling of the spontaneous mutation rate (control)
- dose-response relationship
- reproducibility of the results.

Results and discussion

Test results
Species / strain:
S. typhimurium TA 1535, TA 1537, TA 98, TA 100 and E. coli WP2
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
no cytotoxicity
Vehicle controls validity:
valid
Untreated negative controls validity:
not applicable
Positive controls validity:
valid
Additional information on results:
TEST-SPECIFIC CONFOUNDING FACTORS
- Solubility: completely soluble in DMSO


ADDITIONAL INFORMATION ON CYTOTOXICITY:
occasionally a slight decrease in the number of revertant colonies was observed at doses >= 2500µg/plate
Remarks on result:
other: other: standard test and pre-incubation test
Remarks:
Migrated from field 'Test system'.

Applicant's summary and conclusion

Conclusions:
Interpretation of results (migrated information):
negative

According to the results of the present study, the test substance is not mutagenic in the Ames test and in the Escherichia coli - reverse mutation assay under the experimental conditions chosen here.
Executive summary:

The test substance was tested for mutagenicity in the Ames test and in the E. coli - reverse mutation assay both in the standard plate test and in the preincubation test with and without the addition of a metabolizing system obtained from rat liver (S-9 mix) using the Salmonella strains TA 1535, TA 100, TA 1537, TA 98 and Escherichia coli 1412 uvrA.

An increase in the number of his + or trp+ revertants was not observed both in the standard plate test and in the preincubation test either without S-9 mix or after the addition of a metabolizing system.