2-methoxy-2-methylbutane

Genetic toxicity: in vitro

Administrative data

Endpoint:

in vitro gene mutation study in bacteria

Remarks:

Type of genotoxicity: gene mutation

Type of information:

migrated information: read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: GLP compliant guideline study, adequate for assessment. However, no data on analytical purity was reported. Study is included as a read across to a similar substance to provide data on a 5th bacterial strain (TA102).

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1996

Report date:

1996

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method B.13/14 (Mutagenicity - Reverse Mutation Test Using Bacteria)

GLP compliance:

yes

Type of assay:

bacterial reverse mutation assay

Test material

Test material information

Constituent 1

Reference substance name:

tert-butyl methyl ether

EC Number:

216-653-1

EC Name:

tert-butyl methyl ether

Cas Number:

1634-04-4

IUPAC Name:

tert-butyl methyl ether

Details on test material:

The report states 'not provided'

Method

Target gene:

his

Species / strain

Species / strain / cell type:

S. typhimurium, other: T98, TA100, TA102, TA1535, TA1537

Metabolic activation:

with and without

Metabolic activation system:

liver S9 fraction (induced with Aroclor 1254) from male SD rats

Test concentrations with justification for top dose:

50, 150, 500, 1500 and 5000 µg/plate

Vehicle / solvent:

water

Controls

Untreated negative controls:

yes

Negative solvent / vehicle controls:

yes

True negative controls:

no

Positive controls:

yes

Positive control substance:

other: hydrazine sulphate (TA1535), 9-aminoacridine HCl monohydrate (TA1537), doxorubicine HCl (TA98 and TA100), mitomycin C (TA102), 2-aminoanthracene (TA1535 and TA1537), 2-aminofluorene (TA98, TA100 and TA102)

Details on test system and experimental conditions:

Two independent experiments were performed, setting up triplicates plates for each experimental point.

The first trial was performed using the plate incorporation assay with and without metabolic activation (incubation: 37 degrees Celsius, 72 hours), while the second one was carried out using the plate incorporation assay without metabolic activation (incubation: 37 degrees Celsius, 72 hours) and the pre-incubation method with metabolic activation (pre-incubation at 37 degrees Celsius for 2 hours, followed by incubation at 37 degrees Celsius for 72 hours).

As the test article is a volatile liquid the plates were placed inside a sealed glass jar as soon as they were prepared.

Evaluation criteria:

A positive response is considered:
the number of revertant colonies is significantly higher when compared with the number of rervertants in the solvent controls
and
either a dose-response can be verified, that is, a positive correlation between the number of revertants and the dose in an interval of a least 3 doses
or a statistically significant increase is recorded at one dose only, when confirmed in independent assays.

Statistics:

After completion of scoring, mean of revertant colonies and standard deviation for each dose are determined, comparison was performed by Student's "t" test.

Results and discussion

Test results

Species / strain:

S. typhimurium, other: TA98, TA100, TA102, TA1535, TA1537

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity

Vehicle controls validity:

valid

Untreated negative controls validity:

not examined

Positive controls validity:

valid

Remarks on result:

other: all strains/cell types tested

Remarks:

Migrated from field 'Test system'.