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Toxicological information

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:
1978
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: The study was conducted according to test protocol that is similar to an appropriate EU test method, with acceptable restrictions. The restrictions were lack of duplicates, range of strains differs from current guideline.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1978
Report Date:
1978

Materials and methods

Test guideline
Qualifier:
equivalent or similar to
Guideline:
OECD Guideline 471 (Bacterial Reverse Mutation Assay)
Deviations:
yes
Remarks:
plates not replicated, range of strains not compliant with current guideline
Principles of method if other than guideline:
Method: other: Methods for detecting carcinogens and mutagens with Salmonella mammalian-microsome mutagenicity test. Mutation Res. 31, 347-364. 1975.
GLP compliance:
no
Type of assay:
bacterial reverse mutation assay

Test material

Reference
Name:
Unnamed
Type:
Constituent

Method

Species / strain
Species / strain / cell type:
other: TA-1535, TA-1537, TA-1538
Metabolic activation:
with and without
Metabolic activation system:
Aroclor induced rat liver S9
Test concentrations with justification for top dose:
0.1, 1.0, 10 and 500 µg/plate
Vehicle / solvent:
ethanol
Controlsopen allclose all
Untreated negative controls:
no
Negative solvent / vehicle controls:
yes
True negative controls:
no
Positive controls:
yes
Positive control substance:
other: 1-nitrosoguanidine
Remarks:
TA 1535 and 100 without activation
Positive controls:
yes
Positive control substance:
other: quinacrine mustard
Remarks:
TA 1537 without activation
Positive controls:
yes
Positive control substance:
2-nitrofluorene
Remarks:
TA 98 and 1538 without activation
Positive control substance:
other: anthraquinone
Remarks:
TA 100 and TA 1535 with activation
Positive control substance:
other: aminoquinoline
Positive control substance:
other: acetyl aminofluorene
Details on test system and experimental conditions:
METHOD OF APPLICATION: in medium; in agar (plate incorporation);

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

NUMBER OF REPLICATIONS: no replicates

DETERMINATION OF CYTOTOXICITY
- Method: no information
Evaluation criteria:
A substance producing a positive dose response over three concentarions, with lowest increse equal to twice the solvent control (TA1535, 1537, 1538) or the highest increase at least twice (TA 100) or 2-3 times (TA 98) is considered positive

Results and discussion

Test results
Species / strain:
other: TA-1535, TA-1537, TA-1538, TA-98, TA-100
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
other: 500 ug/plate
Vehicle controls validity:
valid
Untreated negative controls validity:
not applicable
Positive controls validity:
valid
Remarks on result:
other: all strains/cell types tested
Remarks:
Migrated from field 'Test system'. Remarks: Salmonella typhimurium: TA-1535, TA-1537, TA-1538, TA-98, TA-100

Any other information on results incl. tables

All positive controls produced significantly increased revertants, while the negative controls did not.

No testing strains increased the number of revertants relative to the negative controls when tested with and without metabolic activation.  The maximum number of revertants in the solvent control was 230 (TA 100) and in the treated cultures was 292. The positve control gave a maximum of >1000 revertants (TA 1535)

Applicant's summary and conclusion

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

The test compound, Hexamethylcyclotrisloxane, did not increase the number of revertants in any of the strains tested in a valid, reliable and reproducilbe study. The test substance is considered negative for mutagenicity under the conditions of this test.