Registration Dossier

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
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: scientifically acceptable and well documented

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1997
Report Date:
1997

Materials and methods

Principles of method if other than guideline:
Vorprodukt Katalysator WAZ 5596B was screened with one plate per dose using the Salmonella/microsome test (plate incorporation and preincubation method) for point mutagenic effects in doses up to and including 128 µg per plate on five Salmonella thypimurium LT2 mutants. These comprised the histidine-auxotropic strains TA 1535, TA 100, TA 1537, TA 98 and TA 102.
GLP compliance:
not specified
Type of assay:
bacterial reverse mutation assay

Test material

Reference
Name:
Unnamed
Type:
Constituent

Method

Species / strain
Species / strain / cell type:
S. typhimurium TA 1535, TA 1537, TA 98, TA 100 and TA 102
Additional strain / cell type characteristics:
other: all strains are deep rough, i.e. partly deficient in lipopolysaccharide chains; with the exception of TA 102, all strains have reduced capability to repair DNA-damage
Metabolic activation:
with and without
Metabolic activation system:
S-9 mix
Test concentrations with justification for top dose:
Plate incorporation method: up to and including 128 µg/plate;
Preincubation method: up to and including 128 µg/plate
Controls
Untreated negative controls:
yes
Negative solvent / vehicle controls:
yes
True negative controls:
not specified
Positive controls:
yes
Positive control substance:
other: sodium azide, nitrofurantoin, 4-nitro-1,2-phenylene diamine, mitomycin C, cumene hydroperoxide and 2-aminoanthracene

Results and discussion

Test results
Species / strain:
S. typhimurium TA 1535, TA 1537, TA 98, TA 100 and TA 102
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
cytotoxicity
Remarks:
doses up to and including 16 µg per plate did not cause any bacteriotoxic effects
Vehicle controls validity:
valid
Untreated negative controls validity:
valid
Positive controls validity:
valid
Remarks on result:
other:
Remarks:
Migrated from field 'Test system'.

Any other information on results incl. tables

Doses up to and including 16 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 strong, strain-specific bacteriotaxic effect, so that this range could only be used to a limited extent up to and including 32 µg per plate for assessment purposes.

Applicant's summary and conclusion

Conclusions:
Interpretation of results (migrated information):
negative
Executive summary:

Vorprodukt Katalysator WAZ 5596B was screened with one plate per dose using the Salmonellajmicrosome test (plate incorporation

and preincubation method) for point mutagenic effects in doses of up to and including 128 µg per plate on five Salmonella

typhimurium LT2 mutants. These comprised the histidine-auxotrophic strains TA 1535, TA 100, TA 1537, TA 98 and TA 102.

Doses up to and including 16 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 strong, strain-specific bacteriotaxic effect, so that this range could only be used to a limited extent up to and including 32 µg per plate for assessment purposes.

Evidence of mutagenic activity of Vorprodukt Katalysator WAZ 5596B was not seen. No biologically relevant increase in the mutant count, in comparison with the negative controls, was observed .

The positive controls sodium azide, nitrofurantoin, 4-nitro-1,2-phenylene diamine, cumene hydroperoxide and 2-aminoanthracene

had a marked mutagenic effect, as was seen by a biologically relevant increase in mutant colonies compared to the corresponding negative controls.

Therefore, Vorprodukt Katalysator WAZ 55968 was considered to be non-mutagenic without and with 89 mix in the plate incorporation as well as in the preincubation modification of the Salmonella/microsome test.