Registration Dossier

Diss Factsheets

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:
August 20 -23, 1996
Reliability:
1 (reliable without restriction)

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1996
Report date:
1996

Materials and methods

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

Test material

Constituent 1
Chemical structure
Reference substance name:
o-fluoro-α,α,α-trichlorotoluene
EC Number:
207-692-5
EC Name:
o-fluoro-α,α,α-trichlorotoluene
Cas Number:
488-98-2
Molecular formula:
C7H4Cl3F
IUPAC Name:
1-fluoro-2-(trichloromethyl)benzene

Method

Target gene:
hystidine locus
Species / strain
Species / strain / cell type:
S. typhimurium, other: TA98, TA100
Metabolic activation:
with and without
Metabolic activation system:
S9
Test concentrations with justification for top dose:
The maximum concentration was 5000 ug/plate. The concentration range covered two logarithmic decades.
According to the dose selection criteria the test article was tested at the following concentrations:
3.3; 10; 33.3; 100; 333.3; 1000; 2500 and 5000 ug/plate.
Controls
Untreated negative controls:
yes
Negative solvent / vehicle controls:
yes
Positive controls:
yes
Positive control substance:
sodium azide
other: 2-aminoanthracene and 4-nitro-o-phenylene-diamine

Results and discussion

Test resultsopen allclose all
Species / strain:
S. typhimurium TA 98
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
cytotoxicity
Remarks:
from 1000 to 5000 ug/plate
Species / strain:
S. typhimurium TA 100
Metabolic activation:
with and without
Genotoxicity:
positive
Cytotoxicity / choice of top concentrations:
cytotoxicity
Remarks:
from 1000 to 5000 ug/plate
Additional information on results:
Toxicity evident as a reduction in the number or revertants, was observed in TA98 (+/- S9 mix) and in TA100 (- S9 mix) from 1000 ug/plate up to 5000 ug/plate.
The plates incubated with the test article showed reduced background growth at 333.3 ug/plate and above in strain TA98 and at 1000 ug/plate and above in the absence and at the maximal concentration in the presence of S9 mix in strain TA100.
An increase in revertant colony numbers with factors exceeding the threshold of 2.0 was observed following treatment with test item in strain TA100 at 100 and 333.3 ug/plate without S9 mix and from 1000 up to 5000 ug/plate with S9 mix. At concentrations above 333.3 toxic effects result in a decrease of the number of revertant colonies with a concomitant decrease of the corresponding factor.
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):
positive

In conclusion, it can be stated that during the described mutagenicity test and under the experimental conditions reported, the test article induced gene mutations by base pair changes genome of the strain TA 100.
Therefore, the test item is considered to be mutagenic in this Salmonella tymphimurium reverse mutation assay.