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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
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: Study conducted to OECD guidelines and to GLP.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1995
Report Date:
2005

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 471 (Bacterial Reverse Mutation Assay)
Deviations:
no
GLP compliance:
yes (incl. certificate)
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): Cardolite NC511
- Other: dark brow n liquid

Method

Species / strain
Species / strain / cell type:
S. typhimurium TA 1535, TA 1537, TA 98 and TA 100
Metabolic activation:
with and without
Metabolic activation system:
arochlor induced rat liver S9 extract
Test concentrations with justification for top dose:
0, 50, 150, 500, 1500 or 5000 μg/plate
Vehicle / solvent:
- Vehicle(s)/solvent(s) used: acetone
Controlsopen allclose all
Untreated negative controls:
no
Negative solvent / vehicle controls:
yes
Remarks:
acetone
True negative controls:
no
Positive controls:
yes
Positive control substance:
N-ethyl-N-nitro-N-nitrosoguanidine
Remarks:
TA100 and TA1535
Positive control substance:
9-aminoacridine
Remarks:
TA1537
Positive control substance:
other: 4-nitro-o-phenylenediamine
Remarks:
TA1538
Positive control substance:
4-nitroquinoline-N-oxide
Remarks:
TA98
Details on test system and experimental conditions:
METHOD OF APPLICATION: in agar (plate incorporation)

DURATION
- Exposure duration: 48 hours

NUMBER OF REPLICATIONS: 3

DETERMINATION OF CYTOTOXICITY
-Method: relative total growth
Evaluation criteria:
For a positive result, a dose related and statistically significant increase in mutation rate in one or more strains of bacteria in the presence or absence of S9 at sub-toxic dose levels should be induced.
Statistics:
Dunnet's method of linear regression.

Results and discussion

Test resultsopen allclose all
Key result
Species / strain:
S. typhimurium TA 98
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
no cytotoxicity
Vehicle controls validity:
valid
Untreated negative controls validity:
not valid
Positive controls validity:
valid
Key result
Species / strain:
S. typhimurium TA 100
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
no cytotoxicity
Vehicle controls validity:
valid
Untreated negative controls validity:
not valid
Positive controls validity:
valid
Key result
Species / strain:
S. typhimurium TA 1535
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
no cytotoxicity
Vehicle controls validity:
valid
Untreated negative controls validity:
not valid
Positive controls validity:
valid
Key result
Species / strain:
S. typhimurium TA 1537
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
no cytotoxicity
Vehicle controls validity:
valid
Untreated negative controls validity:
not valid
Positive controls validity:
valid
Additional information on results:
TEST-SPECIFIC CONFOUNDING FACTORS
- Precipitation: Observed at and above 1500 μg/plate

RANGE-FINDING/SCREENING STUDIES: The test material was non-toxic in Salmonella strain TA100 up to 5000 μg/plate.

ADDITIONAL INFORMATION ON CYTOTOXICITY: No toxicity was exhibited to any strain used.

Any other information on results incl. tables

No significant increase in the frequency of revertant colonies of bacteria were recorded for any of the strains used, at any dose level with or without metabolic activation.

Applicant's summary and conclusion

Conclusions:
Interpretation of results (migrated information):
negative

The test material was not genotoxic to Salmonella strains with and without metabolic activation.
Executive summary:

In a reverse gene mutation assay in bacteria, strains TA98, TA100, TA1535 and TA 1537 of S. typhimurium were exposed to cashew nutshell liquid, at concentrations of 0, 50, 150, 500, 1500 and 5000 μg/plate in the presence and absence of mammalian metabolic activation.

The positive controls induced the appropriate responses in the corresponding strains. There was no evidence of induced mutant colonies over background for the test substance. This study is classified as acceptable. This study satisfies the requirement for Test Guideline OECD 471 for in vitro mutagenicity (bacterial reverse gene mutation) data.