1-methylimidazole

Genetic toxicity: in vitro

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

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1989

Report date:

1989

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

Version / remarks:

then in force: adopted 23 May 1983

GLP compliance:

not specified

Type of assay:

bacterial reverse mutation assay

Test material

Test material information

Constituent 1

Reference substance name:

1-methylimidazole

EC Number:

210-484-7

EC Name:

1-methylimidazole

Cas Number:

616-47-7

Molecular formula:

C4H6N2

IUPAC Name:

1-methyl-1H-imidazole

Details on test material:

- Substance number: 89/163
- Batch number: FIS 4/146/3
- Analytical purity: 99.4%

Method

Target gene:

his

Species / strain

Species / strain / cell type:

S. typhimurium TA 1535, TA 1537, TA 98 and TA 100

Metabolic activation:

with and without

Metabolic activation system:

rat liver S-9 mix

Test concentrations with justification for top dose:

0, 20, 100, 500, 2500 and 5000 µg/plate (standard plate and preincubation test)

Vehicle / solvent:

- Vehicle used: water

Controls

Untreated negative controls:

yes

Negative solvent / vehicle controls:

yes

True negative controls:

no

Positive controls:

yes

Positive control substance:

other: with metabolic activation: 2-aminoanthracene, without metabolic activation: N-methyl-N' -nitro-N-nitrosoguanidine, 4-nitro-o-phenyleridiamine, 9-aminoacridine

Details on test system and experimental conditions:

METHOD OF APPLICATION: standard plate test (SPT) and preincubation test (PIT)
SPT: incubation at 37°C for 48 hours
PIT: preincubation at 37°C for the duration of 20 minutes; incubation at 37°C for 48 hours

NUMBER OF REPLICATIONS: three plates per dose/control

Evaluation criteria:

In general, a substance to be characterised as positive in the Ames test has to fulfill the following requirements:
- doubling of the spontaneous mutation rate (control);
- dose-response relationship;
- reproducibility of the results.

Results and discussion

Test results

Test results 1

Species / strain:

S. typhimurium TA 1537

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

True negative controls validity:

not examined

Positive controls validity:

valid

Test results 2

Species / strain:

S. typhimurium TA 1535

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

True negative controls validity:

not examined

Positive controls validity:

valid

Test results 3

Species / strain:

S. typhimurium TA 98

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

True negative controls validity:

not examined

Positive controls validity:

valid

Test results 4

Species / strain:

S. typhimurium TA 100

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

True negative controls validity:

not examined

Positive controls validity:

valid

Test results 5

Species / strain:

E. coli WP2

Remarks:

no 5th strain tested due to guideline then in force

Metabolic activation:

with and without

Genotoxicity:

other: no 5th strain tested due to guideline then in force

Cytotoxicity / choice of top concentrations:

other: no 5th strain tested due to guideline then in force

Vehicle controls validity:

not applicable

Untreated negative controls validity:

not applicable

True negative controls validity:

not applicable

Positive controls validity:

not applicable

Additional information on results:

ADDITIONAL INFORMATION ON CYTOTOXICITY: No bacteriotoxic effect (reduced his- background growth) was observed.
SOLUBILITY: Complete solubility of test substance in aqua dest.

Applicant's summary and conclusion

Conclusions:

Not-mutagenic in the Ames test (OECD471) using S. typh. TA98, TA100, TA1535 and TA1537 +/- metabolic activation.