Dodecane-1,12-diol

Skin irritation / corrosion

Administrative data

Endpoint:

skin irritation: in vitro / ex vivo

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2019

Report date:

2019

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:

2015

Test guideline 2

Qualifier:

according to guideline

Guideline:

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

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

Dodecane-1,12-diol

EC Number:

227-133-9

EC Name:

Dodecane-1,12-diol

Cas Number:

5675-51-4

Molecular formula:

C12H26O2

IUPAC Name:

dodecane-1,12-diol

Test material form:

solid

In vitro test system

Test system:

human skin model

Source species:

human

Cell type:

non-transformed keratinocytes

Justification for test system used:

commercially available test system

Vehicle:

other: ethyl acetate

Details on test system:

RECONSTRUCTED HUMAN EPIDERMIS (RHE) TISSUE
- Model used: epiCS® (CellSystems, Troisdorf, Germany).
- Tissue batch number(s): Cat.-No.CS-1001
- Date of initiation of testing: 01 August 2019
TEMPERATURE USED FOR TEST SYSTEM
- Temperature used during treatment / exposure: RT
- Temperature of post-treatment incubation (of 42 h): 37 ± 2 °C
MTT DYE USED TO MEASURE TISSUE VIABILITY AFTER TREATMENT / EXPOSURE
- MTT concentration: 1 mg/mL
- Incubation time: 3 hours
- Spectrophotometer: EL808, Bio-Tek
- Wavelength: 570 nm
NUMBER OF INDEPENDENT TESTING RUNS / EXPERIMENTS TO DERIVE FINAL PREDICTION:
the optical density of the isopropanol-extracts of 3 insert was determined by duplicate per insert = 6 OD values.
PREDICTION MODEL / DECISION CRITERIA:
- The mean optical density (OD) value obtained with the test item was used to calculate the percentage of viability relative to the negative control, which is set at 100 %.
- A category of UN GHS (Category 2 or Category 1) is predicted if the mean percent tissue viability after exposure and post treatment incubation is less than or equal (≤ ) to 50 %.

The irritating potential of the test item is assessed by determination of its cytotoxic effect on an in vitro reconstructed human epidermis. The test principle is based on the MTT assay reflecting the cell viability after exposure to the topically applied test item.
All tests were performed in triplets for each time point. The test item was applied at a 100 % concentration, i.e. 30 mg per insert for 20 min. Cell viability was measured by the amount of MTT reduction (calculated on the basis of optical density of the negative control).

Control samples:

yes, concurrent negative control

yes, concurrent positive control

Amount/concentration applied:

TEST MATERIAL
- Amount(s) applied: 30 mg (For the solid test item 30 μl of 0.9% NaCl were used to moisten and ensure good contact with the epidermis surface. A piece of nylon mesh was used as a spreading aid).

NEGATIVE CONTROL
- Amount(s) applied (volume or weight): 30 μL
- Concentration (if solution): 0.9 % NaCl

POSITIVE CONTROL
- Amount(s) applied (volume or weight): 30 µL
- Concentration (if solution): 5 % Sodium Dodecyl Sulfate (SDS)

Duration of treatment / exposure:

20 min

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:

mean of 3 cultures

Value:

ca. 95

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:

DEMONSTRATION OF TECHNICAL PROFICIENCY:
- Reliability of the test was previously confirmed by interlaboratory validation

- 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
- Acceptance criteria met for positive control: yes
- Acceptance criteria met for variability between replicate measurements: yes

Any other information on results incl. tables

Sample No.	Test item	Time [min.]	% Cell Viability
1 -3	negative control NaCl 0.9 %	20	100.00
7 -9	test item	20	95.28
4 -6	positive control SDS 5%	20	3.12

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Executive summary:

An in vitro study for predicting non-specific irritating properties of the test item was conducted according to OECD TG 439. The undiluted test item (30 mg per insert) was applied topically to a reconstructed human epidermis model (RhE; epiCS). The cell viability was determined with 95.28 % for the test item as measured by MTT conversion. It is therefore concluded that the test item is not irritating to skin.