(Z)-N-[2-(2-hydroxyethoxy)ethyl]-9-octadecenamide

Skin irritation / corrosion

Administrative data

Endpoint:

skin corrosion: in vitro / ex vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

From February 13, 2017 to February 17, 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

Test guideline 1

Qualifier:

according to guideline

Guideline:

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

Version / remarks:

29 July 2016

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

other: EU Method B40 Bis (In Vitro Skin Corrosion: Human Skin Model Test)

Version / remarks:

31 May 2008

Deviations:

no

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

(Z)-N-[2-(2-hydroxyethoxy)ethyl]-9-octadecenamide

Cas Number:

20429-33-8

Molecular formula:

C22H43NO3

IUPAC Name:

(Z)-N-[2-(2-hydroxyethoxy)ethyl]-9-octadecenamide

Test material form:

solid

Details on test material:

Physical appearance: light yellow paste
Storage conditions: at room temperature

Specific details on test material used for the study:

Batch: LAB 4417; Appearance: light yellow paste
- No correction factor for purity was applied
- Stability at higher temperatures: yes, maximum temperature: 30°C

In vitro test system

Test system:

human skin model

Source species:

human

Cell type:

non-transformed keratinocytes

Cell source:

skin obtained from plastic surgery from multiple donors

Justification for test system used:

Recommended test system in international guidelines (OECD and EC).

Vehicle:

unchanged (no vehicle)

Remarks:

Moistened with Milli-Q water to ensure close contact.

Details on test system:

RECONSTRUCTED HUMAN EPIDERMIS (RHE) TISSUE
- Model used: EpiDerm Skin Model
- Tissue batch number(s): 24982
- Surface: 0.6 cm^2
- Tissues were kept in the refrigerator on the day of receivement for one day

TEMPERATURE USED FOR TEST SYSTEM
- Temperature used during treatment / exposure: 3 minute exposure: room temperature, 1 hour exposure: 36.6 - 37.0°C.
- Temperature of post-treatment incubation: 36.6 - 37.0°C.

REMOVAL OF TEST MATERIAL AND CONTROLS
-Volume and number of washing steps: the tissues were washed with phosphate buffered saline (one washing step)
- Observable damage in the tissue due to washing: no

MTT DYE USED TO MEASURE TISSUE VIABILITY AFTER TREATMENT / EXPOSURE
- MTT concentration: 1 mg/mL
- Incubation time: 3 hours
- Spectrophotometer: TECAN Infinite® M200 Pro Plate Reader
- Wavelength: 570 nm

NUMBER OF REPLICATE TISSUES: 4 (2 tissues for the 3 minute exposure period, 2 tissues for the 1 hour exposure period) + 1 tissue for the negative and the positive control

NUMBER OF INDEPENDENT TEST SEQUENCES / EXPERIMENTS TO DERIVE FINAL PREDICTION: 1

PREDICTION MODEL / DECISION CRITERIA (see table 1 in ''any other informatin on methods'')
A test substance is considered corrosive in the in vitro skin corrosion test if:
a) The relative mean tissue viability obtained after 3-minute treatment compared to the negative control tissues is decreased below 50%.
b) In addition, a test substance considered non-corrosive (viability ≥ 50%) after the 3-minute treatment is considered corrosive if the relative tissue viability after 1-hour treatment with the test substance is decreased below 15%.

A test substance is considered non corrosive in the in vitro skin corrosion test if:
a) The relative mean tissue viability obtained after the 3-minute treatment compared to the negative control tissues is not decreased below 50%.
b) In addition, the relative tissue viability after the 1-hour treatment is not decreased below 15%.

ACCEPTABILITY CRITERIA:
a) The absolute mean OD570 of the two tissues of the negative control should reasonably be within the acceptance limits of OECD 431 (lower acceptance limit ≥0.8 and upper acceptance limit ≤2.8).
b) The mean relative tissue viability following 1-hour exposure to the positive control should be <15%.
c) In the range 20 - 100% viability, the Coefficient of Variation (CV) between tissue replicates should be ≤ 30%.

Control samples:

yes, concurrent negative control

yes, concurrent positive control

Amount/concentration applied:

TEST MATERIAL
- Amount applied: excess amount on tissues moistened with 25 μl Milli-Q water

NEGATIVE CONTROL
- Amount applied: 50 μl

POSITIVE CONTROL
- Amount: 50 μl

Duration of treatment / exposure:

- 3 minutes
- 1 hour

Duration of post-treatment incubation (if applicable):

3 hours

Number of replicates:

4 in total; 2 per exposure period

Results and discussion

In vitro

Results

Results 1

Irritation / corrosion parameter:

% tissue viability

Run / experiment:

Mean of replicates

Value:

99

Vehicle controls validity:

not applicable

Negative controls validity:

valid

Remarks:

100%

Positive controls validity:

valid

Remarks:

29%

Results 2

Irritation / corrosion parameter:

% tissue viability

Run / experiment:

Mean of replicates

Value:

72

Vehicle controls validity:

not applicable

Negative controls validity:

valid

Remarks:

100%

Positive controls validity:

valid

Remarks:

9%

Other effects / acceptance of results:

- OTHER EFFECTS:
- Visible damage on test system: no
- Direct-MTT reduction: no
- Colour interference with MTT: no

ACCEPTANCE OF RESULTS:
- Acceptance criteria met for negative control: yes, the absolute mean OD570 was between the acceptance limits (i.e., 1.382 for the 3 minute exposure period and 1.603 for the 1 hour exposure period).
- Acceptance criteria met for positive control: yes, the mean relative tissue viability following 1 hour exposure was <15% (i.e., 9%).
- Acceptance criteria met for variability between replicate measurements: yes, CV between tissue replicates was ≤30% (i.e., 30% for the 3 minute exposure period and 19% for the 1 hour exposure period).

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

Under the study conditions, the test substance is not corrosive in the in vitro skin corrosion test.

Executive summary:

A study was conducted to determine the skin corrosion potential of the test substance according to the Reconstructed Human Epidermis (RHE) Test method following OECD Guideline 431 and EU Method B.40-BIS. Ability of the test substance to induce skin corrosion on a human three dimensional epidermal model was evaluated. Two tissues of the EpiDerm (EPI-200) model were treated with the test substance for 3 min and 1 h, respectively. Skin tissue was moistened with 25 μl of Milli-Q water and an excess amount of the test substance was applied directly on top of the skin tissue. The relative mean tissue viability obtained after 3 min and 1 h treatments with test substance compared to the negative control tissues was 99 and 72%, respectively. Because the mean relative tissue viability for the test substance was not below 50% after the 3 min treatment and not below 15% after the 1 h treatment the test substance is considered to be not corrosive. After treatment with the negative control, the absorbance values were within the required acceptability criterion, showing the quality of the tissues. The positive control showed clear corrosive effects for both treatment intervals. Under the study conditions, the test substance was not corrosive in the in vitro skin corrosion test (Buskens, 2017).