N-(tert-butyl)benzylamine

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:

1987

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Justification for type of information:

Guideline study under GLP

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1987

Report date:

1987

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

Deviations:

yes

Remarks:

4 strains of S. typhimurium; plate incorporation assay used in both Experiments 1 and 2.

GLP compliance:

yes

Type of assay:

bacterial reverse mutation assay

Test material

Test material information

Constituent 1

Reference substance name:

N-(tert-butyl)benzylamine

EC Number:

222-179-6

EC Name:

N-(tert-butyl)benzylamine

Cas Number:

3378-72-1

Molecular formula:

C11H17N

IUPAC Name:

N-(tert-butyl)benzylamine

Test material form:

liquid

Details on test material:

Distilled NBTB, N-Benzyl-tert-butylamine; N-(1,1-dimethylethyl) benzene-methanamine. Purity 99.3% (average). Liquid. Store at room temperature.

Specific details on test material used for the study:

NBTB, Batch 7200, Purity 98-101%

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

Test concentrations with justification for top dose:

5000, 1500, 500, 150, 50 microgram/plate

Vehicle / solvent:

DMSO

Controls

Untreated negative controls:

yes

Negative solvent / vehicle controls:

yes

True negative controls:

no

Positive controls:

yes

Positive control substance:

9-aminoacridine

2-nitrofluorene

N-ethyl-N-nitro-N-nitrosoguanidine

other: 2-aminoanthracene

Details on test system and experimental conditions:

The plate incorporation assay, with and without metabolic activation, was used in both Experiments 1 and 2, according to published methods of Ames et al., 1973 and McCann et al., 1975.
A preliminary toxicity test was undertaken to determine the appropriate concentration range. The limit dose was 0.05 g/ml or 5 µg/plate in DMSO solvent. Revertant colonies are counted using a Biotran Automatic Colony Counter. Toxic levels were detected as an absence of a complete bacterial lawn or by a significant decrease in revertant colony counts.
S9 Metabolic fraction was prepared fresh from male CD rats injected with Arochlor 1254. On the fifth day, the livers were aseptically removed and processed according to published methods.

Rationale for test conditions:

N-Benzyl-Tert-Butylamine was found to be slightly toxic towards the tester strains at the highest dose level. However, 5000 microgram/plate was chosen as the top dose level in the mutation tests.

Evaluation criteria:

A compound is deemed to provide evidence of mutagenic potential if a statistically significant dose-related increase in the number of revertant colonies is obtained in two separate experiments and if the increase in the number of revertant colonies is at least twice the concurrent solvent control value.

Statistics:

The mean number of revertant colonies for all treatment groups is compared with those obtained for negative and positive control groups. The effect of metabolic activation is assessed by comparing the results obtained both in the presence and absence of the liver microsomal fraction for each treatment group.

Results and discussion

Test results

Test results 1

Key result

Species / strain:

S. typhimurium TA 1535

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

cytotoxicity

Vehicle controls validity:

not applicable

Untreated negative controls validity:

not valid

Positive controls validity:

valid

Test results 2

Key result

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:

not applicable

Positive controls validity:

valid

Test results 3

Key result

Species / strain:

S. typhimurium TA 98

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

cytotoxicity

Vehicle controls validity:

not applicable

Untreated negative controls validity:

not valid

Positive controls validity:

valid

Test results 4

Key result

Species / strain:

S. typhimurium TA 100

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

cytotoxicity

Vehicle controls validity:

not applicable

Untreated negative controls validity:

not valid

Positive controls validity:

valid

Any other information on results incl. tables

There was no evidence of mutagenic potential of N-Benzyl-Tert-Butylamine in any of the strains of S. typhimurium tested.

Applicant's summary and conclusion

Conclusions:

There is no evidence of mutagenic potential of N-Benzyl-Tert-Butylamine in the OECD 471 bacterial test system (with and without metabolic activation) at the concentrations up to 5000 µg/plate. The substance is not mutagenic.