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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
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1995
Report date:
1995

Materials and methods

Test guidelineopen allclose all
Qualifier:
according to guideline
Guideline:
OECD Guideline 471 (Bacterial Reverse Mutation Assay)
Deviations:
no
Qualifier:
according to guideline
Guideline:
EU Method B.13/14 (Mutagenicity - Reverse Mutation Test Using Bacteria)
Deviations:
no
GLP compliance:
yes
Type of assay:
bacterial reverse mutation assay

Test material

Constituent 1
Reference substance name:
A mixture of: triphenylthiophosphate and tertiary butylated phenyl derivatives
EC Number:
421-820-9
EC Name:
A mixture of: triphenylthiophosphate and tertiary butylated phenyl derivatives
Cas Number:
192268-65-8
Molecular formula:
Unspecified
IUPAC Name:
A mixture of: triphenylthiophosphate and tertiary butylated phenyl derivatives
Details on test material:
- Appearance: yellowish liquid.
- Storage condition of test material: Room temperature in dark

Method

Target gene:
- S. Typhimurium: Histidine operon
- E. Coli: trpE gene
Species / strain
Species / strain / cell type:
S. typhimurium TA 1535, TA 1537, TA 98, TA 100 and E. coli WP2
Metabolic activation:
with and without
Metabolic activation system:
Aroclor-induced rat liver S9
Test concentrations with justification for top dose:
Concentration range in the main tests (with metabolic activation): 312.5, 625, 1250, 2500 and 5000 µg/plate
Concentration range in the main tests (without metabolic activation): 312.5, 625, 1250, 2500 and 5000 µg/plate
Vehicle / solvent:
Solvent: Dimethylsulfoxide
- Justification for choice of solvent/vehicle: Prior to commencing testing the solubility of the test substance was assessed at 50 mg/ml in water and dimethyl sulphoxide. The test substance was immiscible with water but fully miscible with dimethyl sulphoxide. Therefore dimethyl sulphoxide was chosen as the solvent.
Controlsopen allclose all
Untreated negative controls:
yes
Remarks:
(sterility controls)
Negative solvent / vehicle controls:
yes
Remarks:
(Dimethyl sulfoxide)
Positive controls:
yes
Positive control substance:
N-ethyl-N-nitro-N-nitrosoguanidine
Remarks:
without metabolic activation: 5 µg/plate for strain TA 1535; 3µg/plate for strain TA 100; 2µg/plate for strain WP2 uvrA
Untreated negative controls:
yes
Remarks:
(sterility controls)
Negative solvent / vehicle controls:
yes
Remarks:
(Dimethyl sulfoxide)
Positive controls:
yes
Positive control substance:
9-aminoacridine
Remarks:
without metabolic activation: 80µg/plate for strain TA 1537
Untreated negative controls:
yes
Remarks:
(sterility controls)
Negative solvent / vehicle controls:
yes
Remarks:
(Dimethylsulfoxide)
Positive controls:
yes
Positive control substance:
2-nitrofluorene
Remarks:
without metabolic activation: 1 µg/plate for strain TA 98
Untreated negative controls:
yes
Remarks:
(sterility controls)
Negative solvent / vehicle controls:
yes
Remarks:
(Dimethylsulfoxide)
Positive controls:
yes
Positive control substance:
other: 2-aminoanthracene
Remarks:
with metabolic activation for strains: 2 µg/plate for TA 1535 and TA 1537, 0.5 µg/plate for TA 98, 1 µg/plate for TA 100 and 10 µg/plate for WP2 uvrA
Details on test system and experimental conditions:
METHOD OF APPLICATION: in agar (plate incorporation)

DURATION
- Exposure duration: 3 days at 37°C.

NUMBER OF REPLICATIONS: 2 experiments á 3 plates per experiment.

DETERMINATION OF CYTOTOXICITY
- Method: reduction in revertant colony counts or by the absence of a complete background bacterial lawn.
Evaluation criteria:
The mean number of revertant colonies for all treatment groups is compared with those obtained for solvent control groups. The mutagenic activity of a test substance is assessed by applying the following criteria:

(a) If treatment with a test substance produces an increase in revertant colony numbers of at least twice the concurrent solvent controls, with some evidence of a positive dose-relationship, in two separate experiments, with any bacterial strain either in the presence or absence of S-9 mix, it is considered to show evidence of mutagenic activity in this test system.

(b) If treatment with a test substance does not produce reproducible increases of at least 1.5 times the concurrent solvent controls, at any dose level with any bacterial strain, it is considered to show no evidence of mutagenic activity in this test system.

Statistics:
No statistical analysis was performed.

Results and discussion

Test results
Species / strain:
other: S. typhimurium TA 1535, TA 1537, TA 98, TA 100 and E. coli WP2
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
no cytotoxicity nor precipitates, but tested up to recommended limit concentrations
Vehicle controls validity:
valid
Untreated negative controls validity:
valid
Positive controls validity:
valid
Additional information on results:
Observations:
No increase in the frequency of revertant colonies was recorded for any of the bacterial strains at any dose both with and without metabolic activation. The solvent control plates gave counts in the expected ranges. All positive controls produced marked increases in the revertant counts. Precipitation of the test article in solution occurred with all strains from concentrations of 1250 µg/plate and above
Remarks on result:
other: all strains/cell types tested
Remarks:
Migrated from field 'Test system'.

Applicant's summary and conclusion