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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:
2017
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2018
Report Date:
2018

Materials and methods

Test guidelineopen allclose all
Qualifier:
according to
Guideline:
OECD Guideline 431 (In Vitro Skin Corrosion: Human Skin Model Test)
Qualifier:
according to
Guideline:
EU Method B.40 (In Vitro Skin Corrosion: Transcutaneous Electrical Resistance Test (TER))
GLP compliance:
yes (incl. certificate)

Test material

Reference
Name:
Unnamed
Test material form:
solid: particulate/powder

In vitro test system

Test system:
human skin model
Source species:
human
Cell type:
non-transformed keratinocytes
Cell source:
foreskin from a single donor
Justification for test system used:
Standard test system
Vehicle:
water
Details on test system:
RECONSTRUCTED HUMAN EPIDERMIS (RHE) TISSUE
- Model used: Epiderm kit
- Tissue batch number(s): 25858
- Delivery date: 2017-11-14

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

MTT DYE USED TO MEASURE TISSUE VIABILITY AFTER TREATMENT / EXPOSURE
- MTT concentration: 1 mg/ml
- Incubation time: 1h
- Spectrophotometer: Anthos Reader 2010 Flexi
- Wavelength: 570 nm

NUMBER OF REPLICATE TISSUES: 3

Control samples:
yes, concurrent negative control
yes, concurrent positive control
Amount/concentration applied:
TEST MATERIAL
- Amount(s) applied (volume or weight with unit): 25-26mg

VEHICLE
- Amount(s) applied (volume or weight with unit): 25µl water

NEGATIVE CONTROL
- Amount(s) applied (volume or weight): 50µl water

POSITIVE CONTROL
- Amount(s) applied (volume or weight): 50µl potassium hydroxide
- Concentration (if solution): 8M KOH
Duration of treatment / exposure:
3 minutes / 60 minutes
Number of replicates:
duplicate

Results and discussion

In vitro

Resultsopen allclose all
Irritation / corrosion parameter:
% tissue viability
Run / experiment:
3 min
Value:
ca. 84.7
Negative controls validity:
valid
Positive controls validity:
valid
Irritation / corrosion parameter:
% tissue viability
Run / experiment:
60 min
Value:
ca. 45.1
Negative controls validity:
valid
Positive controls validity:
valid
Other effects / acceptance of results:
The acceptance criteria were fulfilled, the test is considered valid.

Any other information on results incl. tables

After 3 minutes treatment with the test item, the mean value of relative tissue viability was reduced to 84.7 %. This value is above the threshold for corrosion potential (50%). After 1 hour treatment, the mean value of relative tissue viability was reduced to 45.1 %. This value, too, is above the threshold for corrosion potential (15%).

Applicant's summary and conclusion

Interpretation of results:
GHS criteria not met
Conclusions:
The test item is considered non-corrosive to skin.
After 3 minutes treatment, the mean value of relative tissue viability of the test item was decreased to 84.7% This value is well above the threshold for corrosivity (50%). After 1 hour treatment the mean value of relative tissue viability of the test item was reduced to 45.1%. This value is above the threshold for cor-rosivity (15%).

The values of the negative control met the required acceptability criterion of mean OD ≥ 0.8 and ≤ 2.8 for both treatment intervals, thus showing the quality of the tissues.
The positive control has met the validity criterion too, thus ensuring the validity of the test system.

For these reasons, the result of the test is considered valid.
Executive summary:

Two tissues of the human skin model EpiDermTMwere treated with the test itemAmmonium hexafluorocirconatefor 3 minutes and 1 hour, respectively. The test item was applied to each tissue and spread to match the tissue size.

Demineralised water was used as negative control, 8 M KOH was used as positive control.

After treatment, the respective substance was rinsed from the tissues. Then, cell viability of the tissues was evaluated by addition of MTT, which can be reduced to a blue formazan. Formazan production was evaluated by measuring the optical density (OD) of the resulting solution.

After treatment with the negative control, the absorbance values were within the required acceptability criterion of mean OD ≥ 0.8 and ≤ 2.8 for both treatment intervals thus showing the quality of the tissues. The OD was 1.7 (3 minutes experiment) and 1.6 (1 hour experiment).

The positive control showed clear corrosive effects for both treatment intervals. The mean relative tissue viability value was reduced to 6.1 % for the 1 hour treatment.

After 3 minutes treatment with the test item, the mean value of relative tissue viability was reduced to 84.7 %. This value is above the threshold for corrosion potential (50%). After 1 hour treatment, the mean value of relative tissue viability was reduced to 45.1 %. This value, too, is above the threshold for corrosion potential (15%).

 

Therefore, the test item is considered non-corrosive to skin in the Reconstructed Human Epidermis (RHE) Test Method.