Registration Dossier

Diss Factsheets

Toxicological information

Genetic toxicity: in vitro

Currently viewing:

Administrative data

Endpoint:
in vitro gene mutation study in bacteria
Remarks:
Type of genotoxicity: gene mutation
Type of information:
migrated information: read-across based on grouping of substances (category approach)
Adequacy of study:
key study
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: According to OECD 471 guidelines. GLP.
Justification for type of information:
A discussion and report on the read across strategy is given as an attachment in IUCLID Section 13.
Cross-reference
Reason / purpose for cross-reference:
read-across: supporting information
Reference
Endpoint:
in vitro gene mutation study in bacteria
Remarks:
Type of genotoxicity: gene mutation
Type of information:
read-across from supporting substance (structural analogue or surrogate)
Adequacy of study:
key study
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: According to OECD 471 guidelines. GLP.
Justification for type of information:
A discussion and report on the read across strategy is given as an attachment in IUCLID Section 13.
Reason / purpose for cross-reference:
read-across source
Key result
Species / strain:
S. typhimurium TA 1535, TA 1537, TA 98 and TA 100
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
cytotoxicity
Vehicle controls validity:
valid
Untreated negative controls validity:
valid
Positive controls validity:
valid
Additional information on results:
Toxicity pretest was performed from doses of 556, 1667, 5000 ug/plate using all strains. Toxicity was observed at all of these doses and in phase 2 of the study, the doses were reduced to 0, 32, 63, 125, 250, 500 ug/plate.
Remarks on result:
other: all strains/cell types tested
Remarks:
Migrated from field 'Test system'.
Conclusions:
Interpretation of results: negative

In all cases, the test material did not induce any significant changes in the number of revertant colonies.  It is concluded in this study that the test material is not a mutagenic agent and is not classified under the new Regulation (EC) 1272/2008 on classification, labeling, and packaging of substances and mixtures (CLP) or under the Directive 67/518/EEC for dangerous substances and Directive 1999/45/EC for preparations.
Executive summary:

This data is being read across from the source study that tested Hydrocarbons, C10-C13, aromatics, >1% naphthalene based on analogue read across.

Test material was examined for mutagenic activity in the bacterial reverse mutation test using histidine-requiring Salmonella typhimurium strains TA 1535, 1537, 98, and 100, and the E. coli strain WP2 uvr A in the absence and presence of a liver S9 fraction for metabolic activation. Concentrations above 500 ug/plate were found to be cytotoxic and so the test was performed in triplicate using doses of 0, 32, 63, 125, 250, 500 ug/plate.  In all cases, the test material did not induce any significant changes in the number of revertant colonies.  It is concluded in this study that the test material is not a mutagenic agent and is not classified under the new Regulation (EC) 1272/2008 on classification, labeling, and packaging of substances and mixtures (CLP) or under the Directive 67/518/EEC for dangerous substances and Directive 1999/45/EC for preparations.  

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2001
Report date:
2001

Materials and methods

Test guideline
Qualifier:
according to guideline
Guideline:
OECD Guideline 471 (Bacterial Reverse Mutation Assay)
Deviations:
no
GLP compliance:
yes
Type of assay:
bacterial reverse mutation assay

Test material

Constituent 1
Chemical structure
Reference substance name:
Hydrocarbons, C10-C13, aromatics, >1% naphthalene
EC Number:
926-273-4
Molecular formula:
None available - not a single isomer - see remarks
IUPAC Name:
Hydrocarbons, C10-C13, aromatics, >1% naphthalene

Method

Species / strainopen allclose all
Species / strain / cell type:
S. typhimurium TA 1535, TA 1537, TA 98 and TA 100
Species / strain / cell type:
E. coli WP2 uvr A
Metabolic activation:
with and without
Metabolic activation system:
S9 liver fractions from Aroclor exposed rats
Test concentrations with justification for top dose:
Tests (done in triplicate) with and without Metabolic Activation: 0, 32, 63, 125, 250, 500 ug/plate
Positive controls:
TA 1535 (S9-: sodium azide 1.0 ug/plate) (S9+: 2-aminoanthracene: 2.0 ug/plate)
TA 1537 (S9-: 9-aminoacridine 80 ug/plate) (S9+: benzo(a)pyrene: 4.0 ug/plate)
TA 98 (S9-: 2-nitrofluorene 2.0 ug/plate) (S9+: 2-aminoanthracene: 2.0 ug/plate)
TA 100 (S9-: sodium azide 1.0 ug/plate) (S9+: 2-aminoanthracene: 2.0 ug/plate)
WP2 uvr A (S9-: N-ethyl-N-nitrosourea 100 ug/plate) (S9+: 2-aminoanthracene: 80 ug/plate)
Vehicle / solvent:
- Vehicle(s)/solvent(s) used: DMSO
Controls
Untreated negative controls:
yes
Negative solvent / vehicle controls:
no
True negative controls:
yes
Remarks:
non treated
Positive controls:
yes
Positive control substance:
other: See Test Concentrations
Details on test system and experimental conditions:
METHOD OF APPLICATION: in agar
DURATION
- Exposure duration: 48 hours


NUMBER OF REPLICATIONS:
- triplicate

DETERMINATION OF CYTOTOXICITY
- Method: reduction in the number of revertants and/or clearing of the background lawn of bacterial growth
Evaluation criteria:
The mutagenicity study is considered valid if the mean colony counts of the control values of the strains are within acceptable ranges, if the positive controls meet the criteria for a positive response and if no more than 5% of the plates are lost through contamination or other unforeseen events.

A test substance is considered to be positive in the bacterial gene mutation test if the mean number of revertant colonies on the test plates increase in a concentration-related manner and/or if a reproducible two-fold or more increase is observed compared to that on the negative control plates.

A test substance is considered negative in the bacterial gene mutation test if it produces neither a dose-related increase in the mean number of revertant colonies nor a reproducible positive response at any of the test points.

Positive results from the bacterial reverse mutation test indicate that a substance induces point mutations by base substitution or frameshifts in the genome of Salmonella typhimurium. Negative results indicate that under the test conditions, the test substance is not mutagenic.
Statistics:
The mean plate count and standard deviation for each dose point were determined. Any test value that was equal to or greater than two times the mean value of the concurrent vehicle control was considered to be a positive dose.

Results and discussion

Test results
Key result
Species / strain:
S. typhimurium TA 1535, TA 1537, TA 98 and TA 100
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
cytotoxicity
Vehicle controls validity:
valid
Untreated negative controls validity:
valid
Positive controls validity:
valid
Additional information on results:
Toxicity pretest was performed from doses of 556, 1667, 5000 ug/plate using all strains. Toxicity was observed at all of these doses and in phase 2 of the study, the doses were reduced to 0, 32, 63, 125, 250, 500 ug/plate.
Remarks on result:
other: all strains/cell types tested
Remarks:
Migrated from field 'Test system'.

Applicant's summary and conclusion

Conclusions:
Interpretation of results: negative

In all cases, the test material did not induce any significant changes in the number of revertant colonies.  It is concluded in this study that the test material is not a mutagenic agent and is not classified under the new Regulation (EC) 1272/2008 on classification, labeling, and packaging of substances and mixtures (CLP) or under the Directive 67/518/EEC for dangerous substances and Directive 1999/45/EC for preparations.
Executive summary:

Test material was examined for mutagenic activity in the bacterial reverse mutation test using histidine-requiring Salmonella typhimurium strains TA 1535, 1537, 98, and 100, and the E. coli strain WP2 uvr A in the absence and presence of a liver S9 fraction for metabolic activation. Concentrations above 500 ug/plate were found to be cytotoxic and so the test was performed in triplicate using doses of 0, 32, 63, 125, 250, 500 ug/plate.  In all cases, the test material did not induce any significant changes in the number of revertant colonies.  It is concluded in this study that the test material is not a mutagenic agent and is not classified under the new Regulation (EC) 1272/2008 on classification, labeling, and packaging of substances and mixtures (CLP) or under the Directive 67/518/EEC for dangerous substances and Directive 1999/45/EC for preparations.