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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:
from 25 MAR 1986 to 9 MAY 1986
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: Guideline study (OECD 471)

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1986
Report Date:
1986

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 471 (Bacterial Reverse Mutation Assay)
Deviations:
yes
Remarks:
: in addition to the proposed strains, TA1538 was tested
GLP compliance:
yes
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): Hoechst Wachs E

Method

Target gene:
histidine revertants (Salmonella), tryptophan-dependent revertants (E. coli)
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 1538
Species / strain / cell type:
E. coli WP2 uvr A
Metabolic activation:
with and without
Metabolic activation system:
S-9 fraction of Aroclor 1254-induced Sprague-Dawley rats
Test concentrations with justification for top dose:
first experiment: 0, 4, 20, 100, 500, 2500, 10000 µg/plate
second experiment: 0, 4, 20, 100, 500, 2500, 5000 µg/plate
Vehicle / solvent:
DMSO
Controlsopen allclose all
Untreated negative controls:
yes
Negative solvent / vehicle controls:
yes
True negative controls:
no
Positive controls:
yes
Positive control substance:
sodium azide
Remarks:
for TA 100 and TA 1535 without metabolic activation
Untreated negative controls:
yes
Negative solvent / vehicle controls:
yes
True negative controls:
no
Positive controls:
yes
Positive control substance:
9-aminoacridine
Remarks:
for TA 1537 without metabolic activation
Untreated negative controls:
yes
Negative solvent / vehicle controls:
yes
True negative controls:
no
Positive controls:
yes
Positive control substance:
2-nitrofluorene
Remarks:
for TA 98 and TA 1538 without metabolic activation
Untreated negative controls:
yes
Negative solvent / vehicle controls:
yes
True negative controls:
no
Positive controls:
yes
Positive control substance:
N-ethyl-N-nitro-N-nitrosoguanidine
Remarks:
for WP2 uvrA without metabolic activation
Untreated negative controls:
yes
Negative solvent / vehicle controls:
yes
True negative controls:
no
Positive controls:
yes
Positive control substance:
benzo(a)pyrene
Remarks:
all strains with metabolic activation
Untreated negative controls:
yes
Negative solvent / vehicle controls:
yes
True negative controls:
no
Positive controls:
yes
Positive control substance:
other: 2-aminoanthracene
Remarks:
all strains with metabolic activation
Details on test system and experimental conditions:
METHOD OF APPLICATION: in medium; in agar (plate incorporation)

DURATION
- Exposure duration: 48-72 h
- Expression time (cells in growth medium): 48-72 h

SELECTION AGENT (mutation assays): histidine for Salmonella strains, tryptophan for E. coli


DETERMINATION OF CYTOTOXICITY
- Method: determination of spontaneously occuring colonies, thinning of bacterial lawn

Evaluation criteria:
not stated
Statistics:
Results were analysed statistically, but the method was not stated

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
Cytotoxicity / choice of top concentrations:
no cytotoxicity, but tested up to precipitating concentrations
Remarks:
visible precipitation at 2500 µg/plate and above
Vehicle controls validity:
valid
Untreated negative controls validity:
not examined
Positive controls validity:
valid
Species / strain:
S. typhimurium TA 1538
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
no cytotoxicity, but tested up to precipitating concentrations
Remarks:
visible precipitation at 2500 µg/plate and above
Vehicle controls validity:
valid
Untreated negative controls validity:
not examined
Positive controls validity:
valid
Species / strain:
E. coli WP2 uvr A
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
no cytotoxicity, but tested up to precipitating concentrations
Remarks:
visible precipitation at 2500 µg/plate and above
Vehicle controls validity:
valid
Untreated negative controls validity:
not examined
Positive controls validity:
valid
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 without metabolic activation
negative with metabolic activation

The test substance was not mutagenic in these bacterial tests, both with and without metabolic activation.
Executive summary:

A bacterial mutagenicity test (according to guideline OECD 471) in Salmonella typhimurium strains TA100, TA 1535, TA 1537, TA 1538 and TA 98 as well as Ecscherichia coli strain WP2 uvrA was performed with Hoechst Wachs E in concentrations up to 10000 µg/plate with and without metabolic activation . The test substance was not mutagenic under these conditions. Appropriate positive controls showed a mutagenic response, thus confirming the validity of this study.