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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:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
comparable to guideline study with acceptable restrictions

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2012
Report Date:
2012

Materials and methods

Test guideline
Qualifier:
equivalent or similar to
Guideline:
OECD Guideline 471 (Bacterial Reverse Mutation Assay)
GLP compliance:
no
Type of assay:
bacterial reverse mutation assay

Test material

Reference
Name:
Unnamed
Type:
Constituent

Method

Species / strainopen allclose all
Species / strain / cell type:
S. typhimurium TA 98
Details on mammalian cell type (if applicable):
strain hisD3052 rfa, uvrB +R
Species / strain / cell type:
other: Mixed strains of S.typhimurium (TA7001-7006)
Metabolic activation:
with and without
Metabolic activation system:
S9-mix
Test concentrations with justification for top dose:
First experiment: 0, 16, 50, 160, 500, 1600, 5000 µg/mL
Second (repeat) experiment: 0, 0.016, 0.05, 0.16, 0.5, 1.6, 5 µg/mL
Controls
Untreated negative controls:
yes
Remarks:
DMSO
Positive controls:
yes
Positive control substance:
4-nitroquinoline-N-oxide
2-nitrofluorene
other: 2-aminoanthracene

Results and discussion

Test resultsopen allclose all
Key result
Species / strain:
S. typhimurium TA 98
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
cytotoxicity
Remarks:
strong bacterial toxicity in the first experiment
Untreated negative controls validity:
valid
Positive controls validity:
valid
Key result
Species / strain:
other: Mixed strains of S.typhimurium (TA7001-7006)
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
cytotoxicity
Remarks:
strong cytotoxicity in the first experiment
Untreated negative controls validity:
valid
Positive controls validity:
other: valid in the second (repeat) experiment

Applicant's summary and conclusion

Conclusions:
Based on the results, Trans-4-Methyl Cyclohexyl Isocyanate was not mutagenic but was toxic in all strains of S.typhimurium with and without S9-mix at 16 µg/mL and above.