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Diss Factsheets

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:
1985-03-05 to 1985-03-08
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Comparable to guideline study with acceptable restrictions: Incomplete documentation, TA 102 or E.coli WP2 were not tested

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1985
Report date:
1985

Materials and methods

Principles of method if other than guideline:
Ames BN et al. (1975). Mutat. Res. 31, 347-364
GLP compliance:
no
Type of assay:
bacterial reverse mutation assay

Test material

Constituent 1
Chemical structure
Reference substance name:
3-Isocyanatomethyl-3,5,5-trimethylcyclohexyl isocyanate homopolymer, uretdione type
EC Number:
938-351-5
Molecular formula:
residual C12H18N2O2, otherwise C24H36N4O4 (dimer) and higher species
IUPAC Name:
3-Isocyanatomethyl-3,5,5-trimethylcyclohexyl isocyanate homopolymer, uretdione type
Details on test material:
Isophorone diisocyanate oligomer (uretdione type) of Hüls AG, purity not reported

Method

Target gene:
mutated gene loci responsible for histidine auxotrophy
Species / strain
Species / strain / cell type:
other: Salmonella typhimurium TA 1535, TA 1537, TA 1538, TA 98, TA 100
Additional strain / cell type characteristics:
other: histidine auxotroph
Metabolic activation:
with and without
Metabolic activation system:
Aroclor induced rat S9 liver homogenate, male Wistar/TNO/W 74 rats,  enzymatic activity confirmed with aminoanthracene
Test concentrations with justification for top dose:
10 to 5000 µg/plate
Vehicle / solvent:
Acetone (CAS No. 67-64-1)
Controls
Untreated negative controls:
not specified
Negative solvent / vehicle controls:
yes
True negative controls:
not specified
Positive controls:
yes
Positive control substance:
other: with metabolic activation: Aminoanthracene
Details on test system and experimental conditions:
SYSTEM OF TESTING
- Metabolic activation system:    Aroclor induced rat S9 liver homogenate, male Wistar/TNO/W 74 rats,  enzymatic activity confirmed with 
aminoanthracene
ADMINISTRATION: 
- Solvent: acetone (CAS No. 67-64-1)
- Number of replicates: 2
- Pre-incubation: with and without
Evaluation criteria:
CRITERIA FOR EVALUATING RESULTS: 
mutagenic effects (i.e  ratio of revertant rates treated/control >= 2)  at <= 5000 µg/plate with generally positive dose-response relationship in  any 
strain
Statistics:
no data

Results and discussion

Test results
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
other: not reported; probably not observed
Remarks on result:
other: other: Salmonella typhimurium TA 1535, TA 1537, TA 1538, TA 98, TA 100
Remarks:
Migrated from field 'Test system'.

Applicant's summary and conclusion

Conclusions:
Interpretation of results (migrated information):
negative

Under the conditions of the study the test item Isophorone diisocyanate cyclodimer proved to be non-mutagenic, both in the presence and in the
absence of Arochlor-induced liver microsomes, for all test strains used in this study.
Executive summary:

The substance Isophorone diisocyanate cyclodimer was tested in the Ames Salmonella mutagenicity test for any mutagenic activity. The test organisms were five histidine-auxotrophic Salmonella typhimurium strains (TA 1535; TA 1537; TA 1538; TA 98 and TA 100). Under the conditions of the study the test item Isophorone diisocyanate cyclodimer proved to be non-mutagenic, both in the presence and in the absence of Arochlor-induced liver microsomes, for all test strains used in this study.