2-methyl-1-phenylpropan-2-ol

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 08-08-2017 to 22-02-2018

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

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)

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

2-methyl-1-phenylpropan-2-ol

EC Number:

202-896-0

EC Name:

2-methyl-1-phenylpropan-2-ol

Cas Number:

100-86-7

Molecular formula:

C10H14O

IUPAC Name:

2-methyl-1-phenylpropan-2-ol

Test material form:

other: Colourless to slight yellow liquid

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Source and lot/batch No.of test material: Yinghai (Cangzhou) Aroma Chemical Company Ltd./CP001-170601
- Expiration date of the lot/batch: June 1, 2018
- Purity: 99.7 % w/w


STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material: Controlled room temperature (15-25 °C, ≤ 70 RH%), protected from humidity and light.

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:

TEMPERATURE USED FOR TEST SYSTEM
- Temperature used during treatment / exposure: 4 hours (±10 min) at room temperature (23.4-24.6°C) covered with the plate lids.

REMOVAL OF TEST MATERIAL AND CONTROLS
- Number of washing steps: Tissues were thoroughly rinsed with PBS solution to remove the test substance/controls.
- Observable damage in the tissue due to washing: without touching the epidermis
- Modifications to validated SOP: None

DYE BINDING METHOD
- Dye used in the dye-binding assay: MTT
- Spectrophotometer: plate reader
- Wavelength: 570 nm

Control samples:

yes, concurrent negative control

yes, concurrent positive control

Amount/concentration applied:

TEST MATERIAL
- Amount(s) applied (volume or weight with unit): 50 µL

NEGATIVE CONTROL
- Amount(s) applied (volume or weight): 50 μL H2O


POSITIVE CONTROL
- Amount(s) applied (volume or weight): 50 μL
- Concentration (if solution): 8N KOH

Duration of treatment / exposure:

4 hours (±10 min) at room temperature (23.4-24.6°C) covered with the plate lids.

Number of replicates:

2

Results and discussion

In vitro

Results

Irritation / corrosion parameter:

% tissue viability

Run / experiment:

240 minutes

Value:

41.4

Vehicle controls validity:

not applicable

Negative controls validity:

valid

Positive controls validity:

valid

Other effects / acceptance of results:

- OTHER EFFECTS:
- Direct-MTT reduction: After three hours of incubation, yellow colour of the mixture was detected; therefore additional controls were not used in the experiment.
- Colour interference with MTT: As no coloured solution was detected and the test item had no intrinsic colour, no additional colour controls were needed in the experiment to determine the Non Specific Colour (the test item showed no ability to stain the epidermis).


ACCEPTANCE OF RESULTS:
- Acceptance criteria met for negative control: The mean OD value of the two negative control tissues (0.843) was in the recommended range of 0.6 and 1.5.
- Acceptance criteria met for positive control: The two positive control treated tissues showed 0.6% viability, which is in the recommended range of 0 – 20%, demonstrating the proper performance of the assay.
- Acceptance criteria met for variability between replicate measurements:The difference of viability between the two negative control tissue samples in the MTT assay was 1.2% which meets the criteria not exceeding 30%.

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

In conclusion, in this in vitro EPISKIN™(SM) model test with dimethyl benzyl carbinol, the results indicate that the test item is non-corrosive to the skin.

Executive summary:

In an in vitro skin corrosion assay in a human epidermal model EPISKINTM (SM) (17/236-039B), reconstructed human epidermis tissue was exposed to 50 µL of DMBC (99.7%) for 4 hours (±10 min). Physiological saline (0.9% (w/v) NaCl solution) was used for the negative control and glacial acetic acid was used for the positive control. After removal of the test substance, tissues were washed with PBS. Three hours incubation with MTT and an overnight isopropyl alcohol extraction period followed. The OD570 of isopropyl alcohol extracts was measured on a spectrophotometer. Relative cell viability was calculated for each tissue as % of the mean viability of the negative control tissues.

The colour of the test substance did not interfere with the endpoint. The test substance is not directly MTT reducing. The average viability of tissues treated by the test substance DMBC was 41.4% compared to the negative control i.e. viability was > 35%. The average viability of tissues treated by the positive control was 0.6 % of negative control average value. According to these results, the test substance is not corrosive.

This in vitro skin corrosion study in the human epidermal model EPISKINTM (SM) is acceptable and satisfies the guideline requirement for an OECD 431 study.