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Toxicological information

Genetic toxicity: in vitro

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Administrative data

Endpoint:
in vitro gene mutation study in bacteria
Type of information:
experimental study
Adequacy of study:
key study
Study period:
28 Jun. - 07 Aug. 2007
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: GLP guideline 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
GLP compliance:
yes (incl. certificate)
Type of assay:
bacterial reverse mutation assay

Test material

Reference
Name:
Unnamed
Test material form:
liquid
Details on test material:
- additional information as appropriate is presented in the respective study record
Specific details on test material used for the study:
- Name of test material (as cited in study report): Novares LS 500
- Source and lot/batch No.of test material: RÜTGERS Novares GmbH, batch No. 24430
- Composition of test material: composition is specified in IUCLID Sect. 13 - Assessment reports under Certificate of Analysis_Novares LS 500_phenol, styrenated
- Substance type: organic
- Purity test date: 2010/08/05
- 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 / strain
Species / strain / cell type:
S. typhimurium TA 1535, TA 1537, TA 98, TA 100 and 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: 3.16, 10, 31.6, 100, 316, and 1000 µg/plate (TA 98 and TA 100, +/-S9)
1.0, 3.16, 10, 31.6, 100, and 316 µg/plate (TA 1535 and TA 1537, +/-S9)
1.0, 3.16, 10, 31.6, 100, 316, and 1000 µg/plate (TA 102, +/-S9)
2nd experiment: 15.63, 31.25, 62.5, 125, 250, and 500 µg/plate (TA 98 and TA 100, +/-S9)
3.91, 7.81, 15.63, 31.25, 62.5, 125, and 250 µg/plate (TA 1535 and TA 1537, +/-S9)
7.81, 15.63, 31.25, 62.5, 125, 250, and 500 µg/plate (TA 102, +/-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
Remarks:
dist. water
Negative solvent / vehicle controls:
yes
Remarks:
DMSO
Positive controls:
yes
Positive control substance:
2-acetylaminofluorene
sodium azide
methylmethanesulfonate
other: 4-nitro-o-phenylenediamine
Details on test system and experimental conditions:
METHOD OF APPLICATION: in agar (1st and 2nd experiment: plate incorporation 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. 21).

Results and discussion

Test resultsopen allclose all
Species / strain:
S. typhimurium, other: TA 1535, TA 1537, TA 98, and TA 102
Metabolic activation:
with and without
Genotoxicity:
negative
Remarks:
reproducible in both tests
Cytotoxicity / choice of top concentrations:
cytotoxicity
Remarks:
reproducible, >=31 µg/pl. (-S9); >= 125 µg/pl. (+S9), depending on tester strain
Vehicle controls validity:
valid
Untreated negative controls validity:
valid
Positive controls validity:
valid
Species / strain:
S. typhimurium TA 100
Metabolic activation:
with and without
Genotoxicity:
positive
Remarks:
reproducible: at >=100 µg/pl. (-S9) and at >= 250 µg/pl. (+S9)
Cytotoxicity / choice of top concentrations:
cytotoxicity
Remarks:
reproducible: >=31 µg/pl. (-S9); >= 125 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 were observed in the four tester strains, TA 1535, TA 1537, TA 98 and TA 102, following treatment with Novares LS 500, either in the presence or in the absence of metabolic activation.

Biologically relevant, dose-related increases were found in tester strain TA 100 at 100 µg/pl. without S9 and at 316 µg/pl. under metabolic activation (1st exp.) and at 62.5 and 125 µg/pl. without S9 and at 250 µg/pl. with S9 (2nd exp.): a maximum mutation factor of 3 was reached in the presence of S9. The mutagenic doses in the absence or presence of metabolic activation were cytotoxic as well.

All reference mutagens induced distinct increases of revertant colonies indicating the validity of the experiment.

Applicant's summary and conclusion

Conclusions:
The test substance is not considered to be positive in the Ames test as tester strains TA 98, TA 102, TA 1535, and TA 1537 did not show any cytotoxic effects with and without metabolic activation even at cytotoxic concentrations. Only strain TA 100 responded slightly positve at cytotoxic concentrations without clear dose-response relationship.