Butyl carbamate

Genetic toxicity: in vitro

Administrative data

Endpoint:

in vitro gene mutation study in bacteria

Type of information:

experimental study

Adequacy of study:

key study

Study period:

From November 07, 1989 to November 16, 1989

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)

GLP compliance:

yes

Type of assay:

bacterial reverse mutation assay

Test material

Test material information

Constituent 1

Reference substance name:

Butyl carbamate

EC Number:

209-751-0

EC Name:

Butyl carbamate

Cas Number:

592-35-8

Molecular formula:

C5H11NO2

IUPAC Name:

butyl carbamate

Test material form:

solid

Details on test material:

organic

Specific details on test material used for the study:

Purity: > 99%.
Appearance: clearless crystals

Method

Target gene:

Histidine

Species / strain

Species / strain / cell type:

other: S. Typhimurium TA 98, TA 100, TA 1535, TA 1537, TA 1538

Additional strain / cell type characteristics:

other: histidine auxotrophic mutants

Remarks:

amino acid-dependent strains

Metabolic activation:

with and without

Metabolic activation system:

(NADP+)-cytochrome p450 dependent mixed function oxidase enzymes of the liver (S-9)

Test concentrations with justification for top dose:

From 4 µg/plate to 10000 µg/plate
3 plates per condition

Vehicle / solvent:

DMSO (100µL)

Controls

Untreated negative controls:

yes

Remarks:

plate without mutagen

Negative solvent / vehicle controls:

yes

Remarks:

DMSO

Positive controls:

yes

Positive control substance:

9-aminoacridine

2-nitrofluorene

sodium azide

benzo(a)pyrene

other: 2-aminoanthracene

Details on test system and experimental conditions:

Mutagenicity test:
Top agar is prepared for the Salmonella strains by mixing 100 mL agar (0.6% agar, 0.5% NaCl) with 10 mL of a 0.5 mM histidine-biotin solution. The following ingredients are added (in order) to x mL of molten top agar at 45°C:
- 0.1 mL of an overnight nutrient broth culture of the bacterial tester strain
- 0.1 mL test compound solution
- 0.5 mL S-9 Mix (if repuired) or buffer
After mixing, the liquid is poured into a petridish with minimal agar (1.2% agar, Vogel-Bonner E medium with 2% glucose). After incubation for 48 to 72 hours at 37°C in the dark, colonies (his+ revertants) are counted.

Rationale for test conditions:

Toxicity experiments and dose range finding

Evaluation criteria:

Number of his+ revertants

Statistics:

The number of colonies per plate with each strain as well as mean values of 3 plates, corrected to the next whole number

Results and discussion

Test results

Key result

Species / strain:

other: S. Typhimurium TA 98, TA 100, TA 1535, TA 1537, TA 1538

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

Positive controls validity:

valid

Applicant's summary and conclusion

Conclusions:

Under the study conditions, the test substance was not mutagenic in Salmonella typhimurium (bacterial reverse mutation assay).

Executive summary:

A study was conducted to determine the mutagenic potential of the test substance according to OECD Guideline 471 (bacterial reverse mutation assay), in compliance with GLP. Five S. typhimurium strains (i.e. TA 98, TA 100, TA 1535, TA 1537, TA 1538) were exposed to the test substance for 48 to 72 h, at concentrations of 4 to 10000 µg/plate (with 3 plates per condition). At the end of the incubation period, the number of His+ revertants was counted. The test subtance did not cause a significant increase in the number of revertant colonies with any of the tester strains, either in the absence or presence of metabolic activation. Positive and negative (vehicle) controls gave expected results; the experiment was therefore considered valid. Under the study conditions, the test substance was not mutagenic in Salmonella typhimurium (Muller, 1989).