Sodium 2-butoxyethyl sulphate

Skin irritation / corrosion

Administrative data

Endpoint:

skin corrosion: in vitro / ex vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

10 Oct 2017 - 21 Nov 2017

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2017

Report date:

2017

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 431 (In Vitro Skin Corrosion: Reconstructed Human Epidermis (RHE) Test Method)

Version / remarks:

29 July 2016

GLP compliance:

yes (incl. QA statement)

Remarks:

Országos Gyógyszerészeti és Élelmezés-egészégügyi Intézet

Test material

Test material information

Constituent 1

Reference substance name:

Sodium 2-butoxyethyl sulphate

EC Number:

266-840-7

EC Name:

Sodium 2-butoxyethyl sulphate

Cas Number:

67656-24-0

Molecular formula:

C6H14O5S.Na

IUPAC Name:

sodium 2-butoxyethyl sulphate

Test material form:

solid

In vitro test system

Test system:

human skin model

Source species:

human

Cell type:

non-transformed keratinocytes

Cell source:

other: Adult donors

Vehicle:

unchanged (no vehicle)

Details on test system:

RECONSTRUCTED HUMAN EPIDERMIS (RHE) TISSUE
- Model used: reconstituted three-dimensional human skin model EPISKIN-SM™ (SkinEthic)
- Tissue batch number(s): 17-EKIN-041
- Expiration date: 16 October 2017

TEMPERATURE USED FOR TEST SYSTEM
- Temperature used during treatment / exposure: 37°C
- Temperature of post-treatment incubation: 37°C

REMOVAL OF TEST MATERIAL AND CONTROLS
-Volume and number of washing steps: EpiSkinTMSM units were rinsed thoroughly with approximately 25 mL PBS 1x solution to remove the test item from the epidermal surface.

MTT DYE USED TO MEASURE TISSUE VIABILITY AFTER TREATMENT / EXPOSURE
- MTT concentration: 2 mL MTT 0.3 mg/mL solution
- Incubation time: 3 h
- Spectrophotometer: Yes, plate spectrophotometer
- Wavelength: 570 nm ± 10nm

FUNCTIONAL MODEL CONDITIONS WITH REFERENCE TO HISTORICAL DATA
- Barrier function: Specification 1.5 mg/mL ≤ IC50 ≥ 3.0 mg/mL; result: 1.9 mg/mL
- Morphology: Specification ≥ 19.5; result: 23.4±0.4, CV = 1.6%
- Contamination: Screened for HIV-1, hepatits B and C, bacteria, yeast, and other fungi. No contaminates were detected.

NUMBER OF REPLICATE TISSUES: In this assay 2 replicates of test item, 2 replicates negative control and 2 replicates positive control were used.

PREDICTION MODEL / DECISION CRITERIA
A substance was considered corrosive Category 1A if tissue viabilities were < 35% after 3 min exposure. A substance was considered corrosive Category 1B/1C if tissue viabilities were ≥ 35% after 3 min exposure AND < 35% after 1 h exposure OR ≥ 35% after 1 hr exposure AND < 35% after 4 h exposure. A substance was considered noncorrosive if tissue viabitilites were ≥ 35% after 4 h exposure.

The test meets acceptance criteria if:
- The mean OD value of the two negative control tissues was 0.965.
- The positive control result showed 2% viability.
- The difference of viability between the two tissue replicates: Negative control: 15%; Positive control: 1%; Test item: 28%

Control samples:

yes, concurrent negative control

Amount/concentration applied:

TEST MATERIAL
- Amount(s) applied: 20 mg test item was added to 2 mL MTT 0.3 mg/mL solution and mixed

NEGATIVE CONTROL
- Amount(s) applied: 9 g/L saline
- Concentration: 100 μL NaCl solution

POSITIVE CONTROL
- Concentration: 50 μL positive control

Duration of treatment / exposure:

4 h

Duration of post-treatment incubation (if applicable):

3 h

Number of replicates:

In this assay 2 replicates of test item, 2 replicates negative control and 2 replicates positive control were used.

Results and discussion

In vitro

Results

Irritation / corrosion parameter:

% tissue viability

Run / experiment:

4 h

Value:

118

Vehicle controls validity:

not examined

Negative controls validity:

valid

Positive controls validity:

valid

Other effects / acceptance of results:

- OTHER EFFECTS:
- Visible damage on test system: The test item did not show significantly reduced cell viability in comparison to the negative control after 4 hours of exposure.
- Direct-MTT reduction: The test item did not interact with the MTT, therefore additional controls and data calculations were not necessary. A false estimation of viability can be precluded.
- Colour interference with MTT: No color change was observed after three hours of incubation during the check-test for possible direct MTT reduction with test item.

ACCEPTANCE OF RESULTS:
- Acceptance criteria met for negative control: yes; mean OD value of the two negative control tissues was 0.965.
- Acceptance criteria met for positive control: yes ; positive control result showed 2 % viability.
- Acceptance criteria met for variability between replicate measurements: yes; the difference of viability between the two tissue replicates: Negative control: 15%; Positive control: 1%; and Test item: 28%

Applicant's summary and conclusion

Interpretation of results:

other: non-corrosive according to Regulation (EC) No 1272/2008

Executive summary:

In an in vitro skin corrosion human skin model test (EpiSkin) according to OECD guideline 431 and in compliance with GLP, mean cell viability was118% after 4 hours of exposure. Therefore, the test item should not be classified as corrosive.