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Toxicological information

Skin irritation / corrosion

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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

Constituent 1
Chemical structure
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.