trans-4-Methylcyclohexyl isocyanate

Genetic toxicity: in vitro

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

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

GLP compliance:

no

Type of assay:

bacterial reverse mutation assay

Test material

Test material information

Constituent 1

Reference substance name:

trans-4-Methylcyclohexyl isocyanate

EC Number:

608-715-5

Cas Number:

32175-00-1

Molecular formula:

C8 H13 N O

IUPAC Name:

trans-4-Methylcyclohexyl isocyanate

Method

Species / strain

Species / strain 1

Species / strain / cell type:

S. typhimurium TA 98

Details on mammalian cell type (if applicable):

strain hisD3052 rfa, uvrB +R

Species / strain 2

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 results

Test results 1

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

Test results 2

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.