Sodium 2-methylbutan-2-olate

Endpoint summary

Description of key information

Skin irritation test (in vitro) shows corrosive potential.

Key value for chemical safety assessment

Skin irritation / corrosion

Link to relevant study records

Reference

Endpoint:

skin corrosion: in vitro / ex vivo

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP study conducted in compliance with OECD guidline TG 435, well documented.

Qualifier:

according to guideline

Guideline:

OECD Guideline 435 (In Vitro Membrane Barrier Test Method for Skin Corrosion)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Species:

other: Corrositex® kit

Strain:

other: reconstituted collagen matrix

Vehicle:

unchanged (no vehicle)

Controls:

other: control vials with positive and negative control

Amount / concentration applied:

The test substance was applied undiluted. Approximately 300 mg of the test substance was added onto the membrane disc (=maximum applicable amount).

Duration of treatment / exposure:

The elapsed time between test-substance application and the first change in the indicator solution (i.e. barrier penetration) is recorded.

Observation period:

3 min until the first change in the indicator solution (up to 4 hours)

Number of animals:

other: 4 Vials

Details on study design:

The Corrositex® assay is a standardized in vitro corrosion test. The Corrositex® Biobarrier Membrane is a test system consisting of a reconstituted collagen matrix. The assay is based on the time that is required for the test substance to penetrate through the Corrositex® Biobarrier Membrane and produce a change in the Chemical Detection System (CDS). The Corrositex® assay is used to determine the corrosive potential of test substances. The assay is limited to testing those materials which cause detectable pH changes in the CDS

Following the acceptance of the positive control the Corrositex® assay is performed for the test substance. Four vials containing the CDS are used for the
test substance. In addition, one vial was used for the PC, NC and for the color (blank) control, each. A membrane disc coated with the biobarrier matrix was
placed into one vial containing the CDS. Application of 500 mg was not possible due to the low specific weight of the test substance. Hence, approximately 300 mg of the test substance was added onto the membrane disc (=maximum applicable amount). An electronic time clock was started with the application.

The vial is observed for three minutes for any change in the CDS. If no color change is observed within three minutes, the remaining membranes are treated with the test substance. An electronic time clock is started with each application. The vials are observed continuously for the first ten minutes. Thereafter the vials are observed for approximately ten minutes around the time points relevant for evaluation or until break through of the test substance occurred.

Irritation / corrosion parameter:

other: overall irritation score

Remarks on result:

other:

Remarks:

Basis: mean. Time point: 8 minutes and 53 seconds. Remarks: mean breakthrough time. (migrated information)

Irritant / corrosive response data:

Sodium-tert-amylate showed a mean break through time of 8 minutes and 53 seconds.

Other effects:

not applicable

Test substance	Vial 1	Vial 2	Vial 3	Vial 4	Mean
12/0112 -1	8:49	9:50	7:23	9:29	8:53

Interpretation of results:

Category 1B (corrosive)

Remarks:

Migrated information Criteria used for interpretation of results: EU

Conclusions:

Based on the observed results and applying the evaluation criteria it was concluded, that the test substance shows a corrosive potential in the Corrositex® - Skin Corrosion Test under the test conditions chosen. The mean break through
time determined in the in vitro membrane barrier test was 8 minutes and 53 seconds.

Endpoint conclusion

Endpoint conclusion:

adverse effect observed (corrosive)

Eye irritation

Endpoint conclusion

Endpoint conclusion:

no study available

Respiratory irritation

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information

Sodium 2-methylbutan-2-olate was tested for skin corrosion in a GLP-guideline study according to OECD guideline 435. An amount of 300 mg of the test substance (maximum applicable amount) was applied onto the membrane disk of a reconstituted collagen matrix. The penetration time and the time required for a change in the Chemical Detection System (CDS) were determined. The mean breakthrough time of the test substance is 8 minutes and 53 seconds. Under the chosen test conditions, the test substance shows a corrosive potential.

Sodium-2-methylbutan-2-olate has a corrosive potential. It has to be expected to have a similar effect on the eyes.

Justification for selection of skin irritation / corrosion endpoint:
One valid study is available.

Justification for selection of eye irritation endpoint:
Due to the skin corrosive potential a similar effect on the eye has to be expected.

Effects on skin irritation/corrosion: corrosive

Effects on eye irritation: corrosive

Justification for classification or non-classification

Sodium-2-methylbutan-2-olate has a corrosive potential. It has to be expected to have similar effect on the eyes.

Based on the available data, a classification of sodium-2-methylbutan-2-olate as skin corrosive category 1B and Eye Corr. 1 according to CLP Regulation (EC) No 1272/2008 is proposed.

As sodium-2 -methylbutan-2 -olate hydrolyses rapidly, the hydrolysis products are also considered relevant for classification according to CLP regulation (EC) No 1272/2008. 2-methylbutan-2-ol (CAS No. 75-85-4) is classified with STOT SE 3 (H335) according to Annex VI of the CLP regulation. Therefore, also the test substance should be classified with STOT SE 3 (H335).