Registration Dossier

Toxicological information

Skin irritation / corrosion

Currently viewing:

Administrative data

Endpoint:
skin corrosion: in vitro / ex vivo
Type of information:
experimental study
Adequacy of study:
key study
Study period:
May 15 - August 7, 2018
Reliability:
1 (reliable without restriction)

Data source

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

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 431 (In Vitro Skin Corrosion: Reconstructed Human Epidermis (RHE) Test Method)
Deviations:
no
GLP compliance:
yes (incl. certificate)
Remarks:
GLP compliance certification included in full study report

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
semi-solid (amorphous): gel
Details on test material:
Identification: [ω-hydroxy-C16 (saturated and unsaturated) and C16 (unsaturated)] fatty acids
Appearance: Brown semi-solid gel (at 20°C)

In vitro test system

Test system:
human skin model
Source species:
human
Cell type:
non-transformed keratinocytes
Cell source:
foreskin from a single donor
Vehicle:
unchanged (no vehicle)
Details on test system:
EpiDerm™ tissues, Lot No. 28368 Kit D, were received from MatTek Corporation (Ashland, MA) on 22 May 2018 and refrigerated at 2-8°C. Before use, tissues were incubated (37±1°C, 5±1% CO2) with assay medium (MatTek) for a one-hour equilibration. Equilibration medium was replaced with fresh medium before dosing.
Control samples:
yes, concurrent negative control
yes, concurrent positive control
Amount/concentration applied:
50 μl of the test article were applied to the top of each EpiDerm™ tissue. Nylon mesh was then placed on top to facilitate even distribution of the test article.
Duration of treatment / exposure:
The test article remained in contact with the EpiDerm™ tissue for 3 minutes at room temperature and 60 minutes at 37±1°C, 5±1% CO2.
Duration of post-treatment incubation (if applicable):
At the end of the exposure period, each EpiDerm™ tissue was rinsed with phosphate buffered saline (PBS) and transferred to a 24-well microplate containing 300 μl of MTT solution (1 mg/ml MTT in DMEM). The tissues were then returned to the incubator for a three-hour MTT incubation period. Following the MTT incubation period, each EpiDerm™ tissue was rinsed with PBS and then treated overnight at room temperature with 2.0 ml of extractant solution (isopropanol) per well.
Number of replicates:
Each treatment with test article or control was conducted in duplicate.

Results and discussion

In vitro

Results
Irritation / corrosion parameter:
% tissue viability
Value:
92.6
Vehicle controls validity:
not applicable
Negative controls validity:
valid
Remarks:
100% mean tissue viability
Positive controls validity:
valid
Remarks:
2% mean tissue viability
Remarks on result:
other: no indication of corrosion
Other effects / acceptance of results:
Viability differences between the two identically treated tissues in all samples and controls at 3 minutes were 0.7% to 8.8%. Viability differences between the two identically treated tissues at 60 minutes were 0.1% to 2.3%. Inter-tissue viability differences at both time points met the acceptance criterion (≤30%).

Any other information on results incl. tables

The summarized results and corrosion classifications are as follows:

  Test and Control Article Identity

Mean Tissue Viability (3 min.)

 Mean Tissue Viability (3 min.)

 Predicted

Corrosivity

[ω-hydroxy-C16 (saturated and unsaturated) and C16 (unsaturated)] fatty acids

 105.5%

92.6% 

Not corrosive 

 Tissue culture water (Negative Control)

100.0% 

 100.0%

 Not corrosive

 8.0N Potassium hydroxide solution

(Positive Control)

 24.0%

 2.0%

 Corrosive

Applicant's summary and conclusion

Interpretation of results:
GHS criteria not met
Conclusions:
The in vitro skin corrosion test was conducted according to OECD 431 guideline and GLP principles. It is concluded that this test is valid and that the test substance is not corrosive in the in vitro skin corrosion test.
Executive summary:

In an in vitro skin corrosion test using a human skin model (MatTek EpiDerm™ human epidermis) performed according to OECD 431 guideline and GLP principles, the influence of the test substance on the viability of human skin was tested. The test substance was applied directly to cultured tissue (50 μL/ tissue, n=2). After 3-minute and 60-minute treatments the substance was removed and the viability of the cells was tested by reduction of MTT. The realtive mean tissue viability obtained after 3-minute and 1-hour treatments with the test substance was 105.5% and 92.6%, respectively. The positive control had a mean cell viability of 2.0% after 1 -hour exposure.

Since the mean relative tissue viability was not below 50% after the 3-minute treatment and not below 15% after the 1-hour treatment, it is concluded that the test substance is not corrosive in the in vitro skin corrosion test.