[3aR-(3aα,5aβ,9aα,9bβ)]decahydro-3a,6,6,9a-tetramethylnaphth[2,1-b]furan-2(1H)-one

Skin irritation / corrosion

Administrative data

Endpoint:

skin corrosion: in vitro / ex vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

November 2015 - February 2016

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2016

Report date:

2016

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

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

Version / remarks:

28 July 2015

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

[3aR-(3aα,5aβ,9aα,9bβ)]decahydro-3a,6,6,9a-tetramethylnaphth[2,1-b]furan-2(1H)-one

EC Number:

209-269-0

EC Name:

[3aR-(3aα,5aβ,9aα,9bβ)]decahydro-3a,6,6,9a-tetramethylnaphth[2,1-b]furan-2(1H)-one

Cas Number:

564-20-5

Molecular formula:

C16H26O2

IUPAC Name:

[3aR-(3aα,5aβ,9aα,9bβ)]decahydro-3a,6,6,9a-tetramethylnaphth[2,1-b]furan-2(1H)-one

In vitro test system

Test system:

human skin model

Source species:

human

Cell type:

non-transformed keratinocytes

Vehicle:

unchanged (no vehicle)

Details on test system:

RECONSTRUCTED HUMAN EPIDERMIS (RHE) TISSUE
- Model used: epiCS, CellSystems
- Tissue batch number(s): 100-AE2058-1
- Production date: November 2015

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

REMOVAL OF TEST MATERIAL AND CONTROLS
-Volume and number of washing steps: 20 times with 1mL PBS
- Observable damage in the tissue due to washing: none
- Modifications to validated SOP: none

MTT DYE USED TO MEASURE TISSUE VIABILITY AFTER TREATMENT / EXPOSURE
- MTT concentration: 1mg/mL
- Incubation time: 2 hrs 55 min
- Spectrophotometer: Elx800, BioTek
- Wavelength: 570 nm

NUMBER OF REPLICATE TISSUES: 3

NUMBER OF INDEPENDENT TEST SEQUENCES / EXPERIMENTS TO DERIVE FINAL PREDICTION: 2

PREDICTION MODEL / DECISION CRITERIA (choose relevant statement)
- The test substance is considered to be corrosive to skin if the viability after 3 minutes exposure is less than 50%, or if the viability after 3 minutes exposure is greater than or equal to 50 % and the viability after 1 hour exposure is less than 15%.
- The test substance is considered to be non-corrosive to skin if the viability after 3 minutes exposure is greater than or equal to 50% and the viability after 1 hour exposure is greater than or equal to 15%.

Control samples:

yes, concurrent negative control

yes, concurrent positive control

Amount/concentration applied:

25 mg

Duration of treatment / exposure:

3 min and 1 hour

Duration of post-treatment incubation (if applicable):

2 hrs 55 minutes (in MTT solution) + 2 hrs (with isopropanol)

Number of replicates:

3

Results and discussion

In vitro

Results

Results 1

Irritation / corrosion parameter:

% tissue viability

Run / experiment:

1

Value:

87.98

Vehicle controls validity:

not applicable

Negative controls validity:

valid

Positive controls validity:

valid

Remarks on result:

no indication of irritation

Results 2

Irritation / corrosion parameter:

% tissue viability

Run / experiment:

2

Value:

109.42

Vehicle controls validity:

not applicable

Negative controls validity:

valid

Positive controls validity:

valid

Remarks on result:

no indication of irritation

Other effects / acceptance of results:

ACCEPTANCE OF RESULTS:
- Acceptance criteria met for negative control: yes
- Acceptance criteria met for positive control: yes
- Acceptance criteria met for variability between replicate measurements: yes

The SD of the viability of negative control epidermises during 1 hr was 26.2%, instead of <= 18% as initially planned. Considering the results obtained, this deviation is considered as without impact on the study conclusions.

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

The results obtained under these experimental conditions enable to conclude that the test item Sclareolide is not corrosive for the skin.

Executive summary:

The test item Sclareolide was applied as supplied, at the dose of 25 mg, to 2 Human skin model surfaces during 3 minutes and 1 hour, followed by a rinse with 20 mL of PBS. Cell viability was then measured by enzymatic conversion of the vital dye MTT into a blue formazan salt that was quantitatively measured after extraction from tissues.

3 minutes and 1 hour after the test item application, the mean percents viability of the epidermis skins treated with the test item were 87.98% and 109.42% (considered as 100%), versus 3.96% and 0.61 %, respectively, with the positive control item (potassium hydroxide 8N).

The results obtained under these experimental conditions enable to conclude that the test item Sclareolide is not corrosive for the skin.