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Key value for chemical safety assessment

Genetic toxicity in vitro

Link to relevant study records
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
Reason / purpose for cross-reference:
read-across source
Reason / purpose for cross-reference:
read-across: supporting information
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 nor precipitates, but tested up to recommended limit concentrations
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 nor precipitates, but tested up to recommended limit concentrations
Vehicle controls validity:
valid
Untreated negative controls validity:
not examined
Positive controls validity:
valid
Additional information on results:
TEST-SPECIFIC CONFOUNDING FACTORS
- Solubility: the test substance formed a milky white suspension in DMSO at 50 mg/mL, the highest stock concentration that was prepared for use on this study.

TOXICITY-MUTATION TEST
No positive mutagenic responses were observed at any dose level in any tester strain in the absence or presence of S9 metabolic activation. No toxicity was observed at any dose level with any tester strain in either the absence or presence of S9. A >50% reduction in mean number of revertants was observed at: 3333 µg/plate for TA98 with S9 activation, 66.7 µg/plate for TA1535 with S9 activation, 3333 µg/plate for TA1537 with S9 activation, 667 µg/plate for TA1535 without S9 activation, and 3333 µg/plate for TA1537 without S9 activation. These reductions occurred at intermediate dose levels with no dose related correlation and are not considered to be biologically relevant. Test substance precipitation was observed starting at 100 µg/plate in the non-activated test system and at all dose levels in the activated testing system with the exception of TA100 with S9 activation where precipitation was observed starting at 333 µg/plate.

MUTAGENICITY TEST
No positive mutagenic responses were observed at any dose level or with any tester strain in either the absence or presence of S9 metabolic activation. No toxicity was observed at any dose level with any tester strain in either the absence or presence of S9. Test substance precipitation was observed at all dose levels (333 to 5000 µg/plate) with all tester strains both in the absence and presence of S9 activation.
Remarks on result:
other: all strains/cell types tested
Remarks:
Migrated from field 'Test system'.
Conclusions:
Interpretation of results: negative

Titanium dioxide showed no evidence of mutagenicity in the bacterial reverse mutation test either in the absence or presence of Aroclor-induced rat liver S9. Based on these results, it is predicted that the structural analogue Titanium oxide (Ti3O5) also shows negative results for the bacterial reverse mutation test.
Endpoint conclusion
Endpoint conclusion:
no adverse effect observed (negative)

Genetic toxicity in vivo

Endpoint conclusion
Endpoint conclusion:
no study available

Additional information

Justification for classification or non-classification