Registration Dossier

Administrative data

Endpoint:
in vitro gene mutation study in bacteria
Type of information:
experimental study
Adequacy of study:
supporting study
Study period:
July 2013
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: comparable to guideline study with acceptable restrictions

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2013
Report Date:
2013

Materials and methods

Test guideline
Qualifier:
equivalent or similar to
Guideline:
OECD Guideline 471 (Bacterial Reverse Mutation Assay)
Deviations:
yes
Remarks:
screening version (only conducted as preincubation modification, only one plate per dose and strain investigated, purity of test item not specified)
GLP compliance:
no
Type of assay:
bacterial reverse mutation assay

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
liquid

Method

Target gene:
Histidine gene locus
Species / strain
Species / strain / cell type:
S. typhimurium TA 1535, TA 1537, TA 98, TA 100 and TA 102
Additional strain / cell type characteristics:
not applicable
Metabolic activation:
with and without
Metabolic activation system:
Aroclor 1254 induced male rat liver S9 mix
Test concentrations with justification for top dose:
0, 5, 10, 50, 100, 250, 500, 1000, 2000 µg/plate




Vehicle / solvent:
DMSO
Controls
Untreated negative controls:
no
Negative solvent / vehicle controls:
yes
True negative controls:
no
Positive controls:
yes
Positive control substance:
other: sodium azide (TA 100 and TA 1535), 2-nitrofluoren (only TA 98), 4-nitro-1,2-phenylene diamine (only TA 1537), cumene hydroperoxide (only TA 102), 2-aminoanthracene (all strains)
Remarks:
The positive controls sodium azide, 2-nitrofluoren, 4-nitro-1,2-phenylene diamine and cumene hydroperoxide were only used without S9 mix; the positive control 2-aminoanthracene was only used with S9 mix.
Details on test system and experimental conditions:
METHOD: Preincubation test; only one plate per dose and strain investigated
Evaluation criteria:
The test substance is classified as mutagenic if there is a concentration-related increase over the range tested and/or an increase at one or more concentrations in the number of revertant colonies per plate in at least one strain with or without metabolic activation system. For TA 1535, TA 1537, TA 100 and TA 98 this increase should be about twice that of negative controls, whereas for TA 102 an increase of less than 2-fold may also be judged a positive result.

In the evaluation of the test results, the magnitude ofthe effects, their reproducibility, bacteriotoxic effects of the test substance, the historical control data obtained in the laboratory and scientific plausibility are taken into consideration.

Any positive test result should be evaluated for its biological relevance.

A test substance for which the results do not meet the above criteria is considered non-mutagenic in this test
Statistics:
not specified

Results and discussion

Test results
Species / strain:
S. typhimurium, other: TA 98, TA 100, TA 102, TA 1535, TA 1537
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
cytotoxicity
Remarks:
strain-specific bacteriotoxic effect at 500 µg per plate and above
Vehicle controls validity:
valid
Untreated negative controls validity:
not examined
True negative controls validity:
not examined
Positive controls validity:
valid

Any other information on results incl. tables

The total colony counts of the 10-6 dilution of bacterial culture confirmed the viability and high cell density of the cultures of the individual strains.

The counts recorded on appropriate solvent control plates confirmed the characteristic spontaneous reversion rates of the tester strains. Furthermore, appropriate positive controls with known mutagens produced the expected numbers of revertant colonies.

Precipitates in the agar were not found.

Doses up to and including 250 μg per plate did not cause any bacteriotoxic effects. Total bacteria counts remained unchanged and no inhibition of growth was observed. At higher doses, the substance had a strain-specific bacteriotoxic effect. This range could nevertheless be used strain-specifically up to 2000 μg per plate for assessment purposes.

Evidence of mutagenic activity of 2-Fluorbenzylchloride was not seen. No biologically relevant increase in the mutant count, in comparison with the negative controls, was observed for any of the five Salmonella strains.

Due to these results 2-Fluorbenzylchloride has to be regarded as non-mutagenic in the Salmonella/microsome mutagenicity test.

Applicant's summary and conclusion

Conclusions:
negative
Executive summary:

2-Fluorbenzylchloride was initially screened with one plate per dose using the Salmonella/microsome preincubation test for point mutagenic effects in doses of up to and including 2000 µg per plate on the five Salmonella typhimurium strains TA 98, TA 100, TA 102, TA 1535 and TA 1537 (similar to OECD TG 471).

Doses up to and including 250 μg per plate did not cause any bacteriotoxic effects. Total bacteria counts remained unchanged and no inhibition of growth was observed. At higher doses, the substance had a strain-specific bacteriotoxic effect. This range could nevertheless be used strain-specifically up to 2000 μg per plate for assessment purposes.

Evidence of mutagenic activity of 2-Fluorbenzylchloride was not seen. No biologically relevant increase in the mutant count, in comparison with the negative controls, was observed for any of the five Salmonella strains.

Therefore, 2-Fluorbenzylchloride was considered to be non-mutagenic without and with S9 mix in the preincubation modification of the Salmonella/microsome test.