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

Skin irritation / corrosion

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

Guideline:

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

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Remarks:

GLP compliance certification included in full study report

Test material

Test material information

Constituent 1

Reference substance name:

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

EC Number:

946-968-6

IUPAC Name:

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

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.