3-methyl-4-phenylbutan-2-ol

Skin irritation / corrosion

Administrative data

Endpoint:

skin irritation: in vitro / ex vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

28 September 2016 - 3 October 2016

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 439 (In Vitro Skin Irritation: Reconstructed Human Epidermis Test Method)

Version / remarks:

28 July 2015

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method B.46 (In Vitro Skin Irritation: Reconstructed Human Epidermis Model Test)

Version / remarks:

23 July 2009

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

1

Reference substance name:

3-methyl-4-phenylbutan-2-ol

EC Number:

260-398-9

EC Name:

3-methyl-4-phenylbutan-2-ol

Cas Number:

56836-93-2

Molecular formula:

C11H16O

IUPAC Name:

3-methyl-4-phenylbutan-2-ol

Test material form:

other: liquid

In vitro test system

Test system:

human skin model

Source species:

other: human

Cell type:

other: epidermal keratinocytes

Cell source:

other: SkinEthic Laboratories, Lyon, France

Source strain:

other: not applicable

Vehicle:

unchanged (no vehicle)

Details on test system:

RECONSTRUCTED HUMAN EPIDERMIS (RHE) TISSUE
- Model used: EPISKIN TM
- Tissue batch number(s): 16-EKIN-039
- Production date/Shipping date: no data
- Delivery date: 27 September 2016
- Date of initiation of testing: 29 September 2016

TEMPERATURE USED FOR TEST SYSTEM
- Temperature used during treatment / exposure / post-treatment incubation: 37 °C

REMOVAL OF TEST MATERIAL AND CONTROLS
- Tissues were washed with phosphate buffered saline to remove residual test item.

MTT DYE USED TO MEASURE TISSUE VIABILITY AFTER TREATMENT / EXPOSURE
- MTT concentration: 0.3 mg/ml in PBS
- Incubation time: 3 hours at 37 °C
- Spectrophotometer: not specified
- Wavelength: 562 nm (without reference fildeter)
- Filter: no data
- Linear OD range of spectrophotometer: no data

NUMBER OF REPLICATE TISSUES: 3

CONTROL TISSUES USED IN CASE OF MTT DIRECT INTERFERENCE
Not required as no MTT colour interference expected (assessment done).

DECISION CRITERIA
- A test substance is considered irritant in the skin irritation test if: The relative mean tissue viability of three individual tissues after 15 minutes of exposure to the test substance and 42 hours of post incubation is ≤50% of the mean viability of the negative controls.
- A test substance is considered non-irritant in the in vitro skin irritation test if: The relative mean tissue viability of three individual tissues after 15 minutes of exposure to the test substance and 42 hours of post incubation is > 50% of the mean viability of the negative controls.

Control samples:

yes, concurrent negative control

yes, concurrent positive control

Amount/concentration applied:

- Applied volume: 10 μL

Duration of treatment / exposure:

15 minutes

Duration of post-treatment incubation (if applicable):

42 hours

Number of replicates:

3

Results and discussion

In vitro

Results

Irritation / corrosion parameter:

% tissue viability

Run / experiment:

Relative mean tissue viability compared to the negative control tissues (=100%)

Value:

109.2

Vehicle controls validity:

not applicable

Negative controls validity:

valid

Positive controls validity:

valid

Remarks:

5.9% viability

Remarks on result:

no indication of irritation

Other effects / acceptance of results:

OTHER EFFECTS:
- Direct-MTT reduction: No colour changes observed
- Colour interference with MTT: No colour changes observed

DEMONSTRATION OF TECHNICAL PROFICIENCY: No data

ACCEPTANCE OF RESULTS:
-The relative mean tissue viability for the positive control treated tissues was 5.9% relative to the negative control treated tissues and the standard deviation value of the viability was 1.7%. The positive control acceptance criteria were therefore satisfied.
-The mean OD562 for the negative control treated tissues was 1.013 and the standard deviation value of the viability was 2.8%. The negative control acceptance criteria were therefore satisfied.
-The standard deviation calculated from individual tissue viabilities of the three identically test item treated tissues was 12.7%. The test item acceptance criterion was therefore satisfied.

Any other information on results incl. tables

Mean OD₅₆₂Values and Viabilities for the Negative Control Item, Positive Control Item and Test Item

Item	OD562 of tissues	Mean OD562 of triplicate tissues	± SD of OD562	Relative individual tissue viability (%)	Relative mean viability (%)	± SD of Relative mean viability (%)
Negative Control Item	0.981 / 1.031 / 1.028	1.013	0.028	96.8 / 101.8 / 101.5	100*	2.8
Positive Control Item	0.078 / 0.045 / 0.058	0.060	0.017	7.7 / 4.4 / 5.7	5.9	1.7
Test Item	1.242 / 0.986 / 1.090	1.106	0.129	122.6 / 97.3 / 107.6	109.2	12.7

OD=Optical Density

SD=Standard deviation

*=The mean viability of the negative control tissues is set at 100%

Applicant's summary and conclusion

Interpretation of results:

other: not a skin irritant

Remarks:

in accordance with EU CLP (1272/2008 and its amendments)

Conclusions:

Under the conditions of this test, the relative mean tissue viability for the test item determined to be 109.2%. This value is well above the 50% viability threshold for irritancy. Based on the results obtained, it can be concluded that Muguesia is not an irritant to skin.

Executive summary:

The possible skin irritation potential of Muguesia was tested in vitro using a human skin model through topical application for 15 minutes. The study procedures described in this report were according to OECD TG 439 guideline and GLP principles. Skin tissue was treated by topical application of 10 μL undiluted test substance. After 42 hours incubation period, determination of the cytotoxic (irritancy) effect was performed. Cytotoxicity is expressed as the reduction of mitochondrial dehydrogenase activity measured by formazan production from (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl-tetrazolium bromide) MTT at the end of treatment. Skin irritation is expressed as the remaining cell viability after exposure to the test substance. Reliable negative and positive controls were included. The positive control had a mean cell viability of 5.9% after 15 minutes exposure. The standard deviation value of the percentage viability of three tissues treated identically was less than 18%, indicating that the test system functioned properly. Under the conditions of this test, the relative mean tissue viability for the test item determined to be 109.2%. This value is well above the 50% viability threshold for irritancy. Based on the results obtained, it can be concluded that Muguesia is not an irritant to skin.