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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:
weight of evidence
Study period:
November 2014
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2015
Report Date:
2015

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 431 (In Vitro Skin Corrosion: Reconstructed Human Epidermis (RHE) Test Method)
GLP compliance:
yes (incl. certificate)

Test material

Reference
Name:
Unnamed
Type:
Constituent
Type:
additive
Test material form:
liquid

In vitro test system

Test system:
human skin model
Source species:
human
Cell type:
non-transformed keratinocytes
Justification for test system used:
commercially available test system
Vehicle:
other: ethyl acetate
Details on test system:
RECONSTRUCTED HUMAN EPIDERMIS (RHE) TISSUE
- Model used: epiCS® (CellSystems, Troisdorf, Germany).
- Tissue batch number(s): Cat.-No.CS-1001
- Date of initiation of testing: 25 Nov 2015
TEMPERATURE USED FOR TEST SYSTEM
- Temperature used during treatment / exposure: room temperature for 3 min- exposure and incubator (37 ± 2 °C) for 60 min- exposure
- Temperature of post-treatment incubation (if applicable): 37 ± 2 °C
MTT DYE USED TO MEASURE TISSUE VIABILITY AFTER TREATMENT / EXPOSURE
- MTT concentration: 1 mg/mL
- Incubation time: 3 hours
- Spectrophotometer: EL808, Bio-Tek
- Wavelength: 570 nm
NUMBER OF INDEPENDENT TESTING RUNS / EXPERIMENTS TO DERIVE FINAL PREDICTION:
the optical density of the isopropanol-extracts of 3 insert was determined by duplicate per insert = 6 OD values.
PREDICTION MODEL / DECISION CRITERIA:
- The mean optical density (OD) value obtained with the test item was used to calculate the percentage of viability relative to the negative control, which is set at 100 %.
- classification according to UN GHS: if the mean percent tissue viability after 3 min-exposure is less than (<) 50 % the test item is classified as corrosive (Category 1A); if the mean percent tissue viability after 3-min-exposure is greater than or equal (≥) to 50 % AND < 15 % after 60-min exposure the test item is classified as corrosive (Category 1B/1C); if the mean percent tissue viability after 60-min-exposure is ≥ 50 % after 3-min exposure AND ≥ 15 % after 60-min exposure the test item is considered as non-corrosive

The corrosive potential of the test item is assessed by determination of its cytotoxic effect on an in vitro reconstructed human epidermis. The test principle is based on the MTT assay reflecting the cell viability after exposure to the topically applied test item.
All tests were performed in triplets for each time point. The test item was applied at a 100 % concentration, i.e. 50 µL per insert for 3 min. (room temperature) and 60 min. Cell viability was measured by the amount of MTT reduction (calculated on the basis of optical density of the negative control).
Control samples:
yes, concurrent negative control
other: yes, solvent of the test material
Amount/concentration applied:
TEST MATERIAL
- Amount(s) applied: 50 μL
- the test item and the solvent ethyl acetate were tested in parallel

NEGATIVE CONTROL
- Amount(s) applied (volume or weight): 50 μL
- Concentration (if solution): 0.9 % NaCl
Duration of treatment / exposure:
3 min and 60 min
Number of replicates:
3

Results and discussion

In vitro

Resultsopen allclose all
Irritation / corrosion parameter:
% tissue viability
Run / experiment:
exposure period: 3 min. - result for test material
Value:
ca. 100
Vehicle controls validity:
not applicable
Negative controls validity:
valid
Remarks on result:
other: the solvent ethyl acetate was tested in parallel and showed 95 % tissue viability
Irritation / corrosion parameter:
% tissue viability
Run / experiment:
exposure period: 60 min. - result for test material
Value:
ca. 61.2
Vehicle controls validity:
not applicable
Negative controls validity:
valid
Remarks on result:
other: the solvent ethyl acetate was tested in parallel and showed 19 % tissue viability
Other effects / acceptance of results:
DEMONSTRATION OF TECHNICAL PROFICIENCY:
- Reliability of the test was previously confirmed by inter-laboratory validation

ACCEPTANCE OF RESULTS:
- Acceptance criteria met for negative control: yes
- Acceptance criteria met for positive control: yes, within regular intervals in the lab
- Acceptance criteria met for variability between replicate measurements: yes

Any other information on results incl. tables

 Sample No.

 Test item

 Time [min.]

 % Viability

 1 -3

  negative control NaCl 0.9 %

 60

 100.00

 4 -6

test item

 60

 61.20

 7 - 9

 solvent ethyl acetate

 60

 18.52

16 -18 

  control NaCl 0.9 %

 3

 100.00

 19 - 21   test item  3  99.63
 22 - 24   solvent ethyl acetate  3  95.05

Applicant's summary and conclusion

Interpretation of results:
other: no corrosive property
Executive summary:

An in vitro study for predicting non-specific corrosive properties of the test item was conducted according to OECD TG 431. The undiluted test item (solution in ethyl acetate; 50 µL per insert) was applied topically to a reconstructed human epidermis model (RhE; epiCS). In parallel the solvent ethyl acetate was tested in this assay to distinguish potential toxicity of the registered substance from solvent toxicity. After an exposure period of 3 min at room temperature and 60 minutes the cell viability was 61.2 % and about 100 %, respectively, for the test item as measured by a MTT conversion assay. It is therefore concluded that the test item is not corrosive to the skin. Also the solvent ethyl acetate did not show corrosive properties according to the criteria of this assay.