Sodium 2-hexyloxyethanolate

Skin irritation / corrosion

Administrative data

Endpoint:

skin corrosion: in vitro / ex vivo

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Meets generally accepted scientific standards, well documented and acceptable for assessment.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2001

Report date:

2001

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

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

Principles of method if other than guideline:

- OECD Guideline for testing of chemicals, draft proposal for a new guideline: "In vitro Skin Corrosion tests", Draft November 1999.

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

2-hexyloxyethanol

EC Number:

203-951-1

EC Name:

2-hexyloxyethanol

Cas Number:

112-25-4

Molecular formula:

C8H18O2

IUPAC Name:

2-(hexyloxy)ethanol

Constituent 2

Reference substance name:

Hexylglycol (EGHE)

IUPAC Name:

Hexylglycol (EGHE)

Details on test material:

- Name of test material (as cited in study report): n-Hexylglykol
- Batch No.: Tank 773 (07.12.00)
- Purity: 99.6 %

Test animals

Species:

other: EpiDerm (reconstructed three dimensional human epidermis model)

Strain:

other: EpiDerm (reconstructed three dimensional human epidermis model)

Details on test animals or test system and environmental conditions:

- Tissue model: Epi-200
- Source: MatTek Corporation, Ashland MA, USA

Test system

Type of coverage:

other: not applicable

Preparation of test site:

other: not applicable

Vehicle:

unchanged (no vehicle)

Controls:

other: Negative control (NC): Doubly distilled water; Positive control (PC): 8 n potassium hydroxyde (Sigma-Aldrich, Munich, Germany); MTT-reduction control (KC): Doubly distilled water or test substance

Amount / concentration applied:

TEST MATERIAL
- Amount applied: 50 µl
- Concentration: undiluted

Duration of treatment / exposure:

3 min and 1 h

Number of animals:

2 EpiDerm tissues per time point

Details on study design:

Test Conditions:
- The potential of the test substance to cause dermal corrosion was assessed by a single topical application of 50 µl of the test substance to a reconstructed three dimensional human epidermis model (EpiDerm). Duplicates of the EpiDerm tissue were incubated with the test substance for 3 min and 1 h, followed by a colorimetric determination of the possibly induced cytotoxic effect.
- Cytotoxicity is expressed as the reduction of mitochondrial dehydrogenase activity, measured by reduced formazan production after incubation with a tetrazolium salt. The formazan production of the test substance treated epidermal tissues is compared to the negative control tissues, calculated as relative tissue viability.
- Evaluation criteria:
mean tissue viability (% negative control) => prediction
3 min: < 50 => corrosive
3 min: >= 50 and 1 hour < 20 => corrosive
3 min: >= 50 and 1 hour: >= 20 => non-corrosive

Results and discussion

In vivo

Irritant / corrosive response data:

Viability of the test substance treated EpiDerm tissues determined after an exposure period of 3 min was 94% and for the exposure period 1 h 9%

Any other information on results incl. tables

- The test substance is able to directly reduce MTT. However, this ability of direct MTT reduction did not impair the study
 result as demonstrated by the concurrently performed exposure of freeze-killed control tissues.

Applicant's summary and conclusion

Interpretation of results:

corrosive

Remarks:

Migrated information Criteria used for interpretation of results: EU

Conclusions:

The test substance has a corrosive potential in the EpiDerm skin corrosivity test

Executive summary:

The study meets generally accepted scientific standards, is well documented and acceptable for assessment. It was conducted in accordance to a draft proposal for a new OECD guideline: "In vitro Skin Corrosion tests" (Draft November 1999).

The potential of the test substance to cause dermal corrosion was assessed by a single topical application of 50 µl of the test substance to a reconstructed three dimensional human epidermis model (EpiDerm). Duplicates of the EpiDerm tissue were incubated with the test substance for 3 minutes and 1 hour, followed by a colorimetric determination of the possibly induced cytotoxic effect. Cytotoxicity is expressed as the reduction of mitochondrial dehydrogenase activity, measured by reduced formazan production after incubation with a tetrazolium salt (MTT assay). The formazan production of the test substance treated epidermal tissues is compared to the negative control tissues, calculated as relative tissue viability.

Viability of the test substance treated tissues determined after an exposure period of 3 minutes was 94 % and for the exposure period 1 hour 9 %. The test substance is able to directly reduce MTT. However, this ability of direct MTT reduction did not impair the study result as demonstrated by the concurrently performed exposure of freeze-killed control tissues.

Conclusion: The test substance has a corrosive potential in the EpiDerm skin corrosivity test (OECD GHS category 1B).