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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
Study period:
19 Jul. - 20 Aug. 2007
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: GLP study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2007
Report Date:
2007

Materials and methods

Test guidelineopen allclose all
Qualifier:
according to
Guideline:
OECD Guideline 471 (Bacterial Reverse Mutation Assay)
Qualifier:
according to
Guideline:
EU Method B.13/14 (Mutagenicity - Reverse Mutation Test Using Bacteria)
Principles of method if other than guideline:
plate incorporation assay and preincubation test
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): Naphthalene oil
- Molecular formula (if other than submission substance): not applicable
- Molecular weight (if other than submission substance): not applicable
- Substance type: organic
- Physical state: solid
- Stability under test conditions: no measured data; based on chemical structure assumed to be stable
- Storage condition of test material: room temperature, exclusion of light

Method

Species / strainopen allclose all
Species / strain / cell type:
S. typhimurium TA 1535, TA 1537, TA 98 and TA 100
Species / strain / cell type:
S. typhimurium TA 102
Metabolic activation:
with and without
Metabolic activation system:
Microsomal fraction prepared from induced livers of male Wistar rats, induced with phenobarbital (80 mg/kg bw) and ß-naphthoflavone (100 mg/kg bw) orally (3x)
Test concentrations with justification for top dose:
1st experiment: 10, 31.6, 100, 316, 1000, 2500, and 5000 µg/plate (all strains, +/-S9)
2nd experiment: 3.16, 10, 31.6, 100, 316, 1000, and 2500 µg/plate (TA 100, TA 102, TA 1535, TA 1537: +/- S9)
10, 31.6, 100, 316, 1000, 2500, and 5000 µg/plate (TA 98: +/- S9)
Vehicle / solvent:
- Vehicle(s)/solvent(s) used: DMSO
- Justification for choice of solvent/vehicle: compatible with survival of bacteria and S9 activity
Controls
Untreated negative controls:
yes
Negative solvent / vehicle controls:
yes
Positive controls:
yes
Positive control substance:
other: see Report p. 14
Details on test system and experimental conditions:
METHOD OF APPLICATION: in agar (1st experiment: plate incorporation); 2nd experiment: preincubation test

NUMBER OF REPLICATIONS: 3 per concentration

DETERMINATION OF CYTOTOXICITY
- Method: relative total growth/colony formation


Evaluation criteria:
Considered as mutagenic
- if a clear and dose-related increase in the number of revertants occurs in at least one tester with or without metabolic activation
and/or
- if a biologically relevant positive response for at least one of the dose groups occurs in at least one tester with or without metabolic activation.

An increase is considered relevant
- if in TA 100 and TA 102 mutation rate is at least twice as high as the rate of the solvent control;
- if in TA 98, TA 1535, and TA 1537 the mutation rate is at least 3x higher than that of the solvent control.


Statistics:
According to the OECD guidelines, the biological relevance is the criterion for the interpretation of the results: a statistical evaluation was not considered necessary under this premise (report p. 20).

Results and discussion

Test resultsopen allclose all
Species / strain:
S. typhimurium TA 1535, TA 1537, TA 98 and TA 100
Metabolic activation:
with and without
Genotoxicity:
negative
Remarks:
reproducible in both tests
Cytotoxicity / choice of top concentrations:
cytotoxicity
Remarks:
at >= 316 or 1000 µg/pl. (+/-S9)
Vehicle controls validity:
valid
Untreated negative controls validity:
valid
Positive controls validity:
valid
Species / strain:
other: TA 102
Metabolic activation:
with and without
Genotoxicity:
negative
Remarks:
reproducible in both tests
Cytotoxicity / choice of top concentrations:
no cytotoxicity
Remarks:
at >= 316 or 1000 µg/pl. (+/-S9)
Vehicle controls validity:
valid
Untreated negative controls validity:
valid
Positive controls validity:
valid

Any other information on results incl. tables

Summary:

No biologically relevant increases in revertant colony numbers of any of the five tester strains were observed following treatment with Naphthalene Oil at any concentration level, neither in the presence nor in the absence of metabolic activation. All reference mutagens induced distinct increases of revertant colonies indicating the validity of the experiment.

Applicant's summary and conclusion

Conclusions:
Interpretation of results (migrated information):
negative