Registration Dossier

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:
experimental study
Adequacy of study:
key study
Study period:
no data available
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: The study is sufficiently documented. Comparable to guideline study with acceptable restrictions (no E. coli or TA102 strain, only one positive control substance for test with metabolic activation)

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1992
Report Date:
1992

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 471 (Bacterial Reverse Mutation Assay)
Deviations:
yes
Remarks:
no E.coli or TA102 strain, only one positive control substance for test with metabolic activation
GLP compliance:
yes
Type of assay:
bacterial reverse mutation assay

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
solid: particulate/powder
Remarks:
migrated information: powder
Details on test material:
See confidential details on test material section

Method

Target gene:
his operon
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:
cofactor supplemented post-mitochondrial fraction (S9 mix), prepared from the livers of rats treated with Aroclor 1254
Test concentrations with justification for top dose:
Standard plate test: 0, 60, 120, 100, 250, 500, 1000, 2000, 2500, 5000, 7500 µg/plate
Preincubation test: 0, 20, 100, 500, 1000, 2000 µg/plate
Vehicle / solvent:
- Vehicle(s)/solvent(s) used: water
Controls
Untreated negative controls:
yes
Negative solvent / vehicle controls:
yes
True negative controls:
no
Positive controls:
yes
Positive control substance:
other: 2-aminoanthracene (with S-9 mix for all strains); N-methyl-N-nitro-N-nitrosoguanidine (without S-9 mix for TA100 and TA1535); 4-nitro-o-phenyldiamine (without S-9 mix for TA98); 9-aminoacridine chloride monohydrate (without S-9 mix for TA1537)
Details on test system and experimental conditions:
METHOD OF APPLICATION: in agar (plate incorporation); preincubation

DURATION
- Preincubation period: 20 minutes
- Exposure duration: 48 hours

NUMBER OF REPLICATIONS: 3

DETERMINATION OF CYTOTOXICITY
- Method: relative total growth

Evaluation criteria:
In general, a substance to be characterized as positive in the Ames test has to fulfill the following requirements:
- doubling of the spontaneous mutation rate (control)
- dose-response relationship
- reproducibility of the results.
Statistics:
no data available

Results and discussion

Test results
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
Remarks:
A bacteriotoxic effect was observed depending on the strain and experimental conditions from about 1000 µg - 2500 µg/plate onward.
Vehicle controls validity:
valid
Untreated negative controls validity:
valid
Positive controls validity:
valid
Additional information on results:
TEST-SPECIFIC CONFOUNDING FACTORS
- Water solubility: Complete solubility of test substance in aqua dest.
Remarks on result:
other: all strains/cell types tested
Remarks:
Migrated from field 'Test system'.

Applicant's summary and conclusion

Conclusions:
Interpretation of results (migrated information):
negative with metabolic activation
negative without metabolic activation

Under these experimental conditions, the test item Reaction product of naphthalene, butanol, sulfonated and neutralized by caustic soda did not show any mutagenic activity in the bacterial reverse mutation test with Salmonella typhimurium.
Executive summary:

This study was performed to investigate the potential of the test item, Reaction product of naphthalene, butanol, sulfonated and neutralized by caustic soda, to induce reverse mutation in Salmonella typhimurium. The test item was tested in two independent experiments, with and without a metabolic activation system, the S9 mix, prepared from a liver post‑mitochondrial fraction (S9 fraction) of rats induced with Aroclor 1254. The first experiment was performed according to the direct plate incorporation method and the second was performed according to the pre-incubation method (20 minutes). 

Four strains of bacteria Salmonella typhimurium TA 1535, TA 1537, TA 98 and TA 100 were used. Each strain was exposed to dose-levels of the test item. The selected dose-levels were: 60, 120, 100, 250, 500, 1000, 2000, 2500, 5000, 7500 µg/plate in the first test and 20, 100, 500, 1000, 2000 µg/plate in the second test. The number of mutations were scored.

A bacteriotoxic effect was observed depending on the strain and test conditions from about 1000 µg – 2500 µg/plate onward. An increase in the number of his revertants was not observed both in the standard plate test and in the pre-incubation test either without S-9 mix or after the addition of the metabolizing system.

In conclusion, the test item did not show any mutagenic activity in the bacterial reverse mutation test with Salmonella typhimurium, in the absence or in the presence of a rat metabolising system therefore Reaction product of naphthalene, butanol, sulfonated and neutralized by caustic soda is not classified according to Annex VI of the Directive 67/548/CEE and according to EU Regulation 1272/2008 (CLP).