2-ethoxy-2-methylpropane

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:

other: GLP-compliant guideline study, no restrictions, fully adequate for assessment.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1994

Report date:

1994

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)

Test guideline 3

Qualifier:

according to guideline

Guideline:

EPA OPPTS 870.5265 (The Salmonella typhimurium Bacterial Reverse Mutation Test)

GLP compliance:

yes

Type of assay:

bacterial reverse mutation assay

Test material

Test material information

Constituent 1

Reference substance name:

2-ethoxy-2-methylpropane

EC Number:

211-309-7

EC Name:

2-ethoxy-2-methylpropane

Cas Number:

637-92-3

Molecular formula:

C6H14O

IUPAC Name:

2-ethoxy-2-methylpropane

Details on test material:

- Name of test material (as cited in study report): ETBE
- Physical state: colourless liquid
- Analytical purity: 95.8%
- Lot/batch No.: 93050601

Method

Target gene:

his

Species / strain

Species / strain / cell type:

S. typhimurium, other: TA 1535, TA 1537, TA 1538, TA98, TA 100

Metabolic activation:

with and without

Metabolic activation system:

 Arochlor 1254-induced rat S9 fraction

Test concentrations with justification for top dose:

First test: 8, 40, 200, 1000 and 5000 ug/plate;
Second test: 313, 625, 1250, 2500 and 5000 ug/plate

Vehicle / solvent:

ethanol

Controls

Untreated negative controls:

yes

Negative solvent / vehicle controls:

yes

True negative controls:

no

Positive controls:

yes

Positive control substance:

other: 2-Nitrofluorene, 9-aminoacridine, sodium  azide, 2-aminoanthracene

Details on test system and experimental conditions:

Commercially-available freeze-dried S9 fraction (MOLTOX Inc) from Arochlor 1254-induced rats was used in these studies. Absolute ethanol was used as carrier solvent, and added at a final volume of 0.05 ml/plate. Each dose was tested in triplicate, with independent repeat. 2-Nitrofluorene (TA 98 and TA 1538), 9-aminoacridine (TA 1537) and sodium azide (TA 1535 and TA 100) were used as positive control substances in the absence of S9 mix, and 2-aminoanthracene (all strains) as positive  control in the presence of S9.

METHOD OF APPLICATION: in agar (plate incorporation)

DURATION:
- Exposure duration: 48 hours (minimum)
- Temperature: 37 +- 1 oC

Evaluation criteria:

Results were considered positive if a suitable response had been obtained with the negative and positive control substances, and the number of revertants in the presence of ETBE was at least twice that of the negative control, with a dose-response correlation.

Statistics:

After completion of scoring, mean of revertant colonies and standard deviation for each dose are determined.

Results and discussion

Test results

Species / strain:

other: Salmonella typhimurium TA 1535, TA 1537, TA 1538, TA98, TA 100

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity

Vehicle controls validity:

not specified

Untreated negative controls validity:

valid

Positive controls validity:

valid

Additional information on results:

Results from a preliminary test using TA 100 (without S9) revealed no toxicity at doses up to 5000 ug/plate. All data met the acceptability criteria established for the test. No increase in the number of revertants was seen with any of the tester stains, both in the absence and presence of S9 fraction, in either the first or second study. A satisfactory response was obtained with the negative and positive controls.

Remarks on result:

other: all strains/cell types tested

Remarks:

Migrated from field 'Test system'.