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
Study period:
2007-08-08 - 2008-04-03
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: non-GLP guideline study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2008
Report Date:
2008

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 471 (Bacterial Reverse Mutation Assay)
Deviations:
no
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): DCBS
- Substance type: organic
- Physical state: white powder
- Analytical purity: no data

Method

Species / strain
Species / strain / cell type:
other: S. typhimurium TA97, TA98, TA100, TA102 and TA1535
Metabolic activation:
with and without
Metabolic activation system:
S9, two concentrations (5% and 10%)
Test concentrations with justification for top dose:
0.05mg/plate, 0.15mg/plate, 0.5mg/plate, 1.5mg/plate, 5mg/plate
Vehicle / solvent:
- Vehicle(s)/solvent(s) used: DMSO
- Justification for choice of solvent/vehicle: According to the physical and chemical state of the test substance and the result of preliminary test, DMSO was selected to be solvent of this test
Controls
Untreated negative controls:
yes
Remarks:
Spontaneous revertant
Negative solvent / vehicle controls:
yes
Remarks:
100µL bacteria solution + 0.5mL PBS + 100µl DMSO/100µL bacteria solution + 0.5mL S9-mix + 100µl DMSO
True negative controls:
no
Positive controls:
yes
Positive control substance:
other: ICR-191, P-NQ, MMS, NaN3, 2-AF, Danthron, and 2-AA
Details on test system and experimental conditions:
METHOD OF APPLICATION: AMES, direct plate incorporation

DURATION
- Preincubation period: not applicable
- Exposure duration: 48 hours

NUMBER OF REPLICATIONS: 160

NUMBER OF CELLS EVALUATED: 160

DETERMINATION OF CYTOTOXICITY
- Method: Number changes of revertant bacteria colony

Results and discussion

Test results
Species / strain:
other: S. typhimurium TA97, TA98, TA100, TA102 and TA1535
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
no cytotoxicity, but tested up to precipitating concentrations
Vehicle controls validity:
valid
Untreated negative controls validity:
valid
Positive controls validity:
valid
Additional information on results:
The number of revertant colonies of 5 dosages (0.05mg/plate~5mg/plate) of DCBS with and without S9-mix (two concentrations) had no significant difference to solvent control.
Remarks on result:
other: all strains/cell types tested

Applicant's summary and conclusion

Conclusions:
Interpretation of results: negative

No toxic effect of the test item was observed in the experimental conditions, therefore, the test item is considered to be non-mutagenic.