2-Propanol, 1,3-bis[(3-methyl-2-buten-1-yl)oxy]-

Skin irritation / corrosion

Administrative data

Endpoint:

skin irritation: in vitro / ex vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2019-07-29 to 2019-08-01

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

Qualifier:

according to guideline

Guideline:

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

Version / remarks:

Adopted : 2015-07-28

Deviations:

no

GLP compliance:

yes

Test material

Test material information

impurity 1

Reference substance name:

Unknown impurities

IUPAC Name:

Unknown impurities

impurity 2

Reference substance name:

1,3-Bis(3-Methyl-2-butenoxy)-2-(3'-(3-Methyl-2-butenoxy)-2'-hydroxypropanoxy)propane

Molecular formula:

C21O5H32

IUPAC Name:

1,3-Bis(3-Methyl-2-butenoxy)-2-(3'-(3-Methyl-2-butenoxy)-2'-hydroxypropanoxy)propane

Constituent 1

Reference substance name:

1,3-bis[(3-methylbut-2-en-1-yl)oxy]propan-2-ol

EC Number:

858-735-5

Cas Number:

2337348-25-9

Molecular formula:

C13H24O3

IUPAC Name:

1,3-bis[(3-methylbut-2-en-1-yl)oxy]propan-2-ol

Test material form:

liquid

In vitro test system

Test system:

human skin model

Remarks:

EpiDerm Sit (EP-200)

Source species:

human

Cell type:

non-transformed keratinocytes

Cell source:

other: Not specified

Source strain:

not specified

Justification for test system used:

EPI-200 SIT kit is recommended in the test method.

Vehicle:

unchanged (no vehicle)

Details on test system:

RECONSTRUCTED HUMAN EPIDERMIS (RHE) TISSUE
- Model used: EPI-200 SIT
- Tissue lot number: 30926
- Production date: 2019-07-25
- Date of initiation of testing: 2019-07-29

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

REMOVAL OF TEST MATERIAL AND CONTROLS
-Volume and number of washing steps: After the exposure, each tissue insert was rinsed fifteen times with PBS(-). Furthermore, tissue inserts were completely submerged three times in 150 mL of PBS(-). Finally, tissue inserts were rinsed once inside and outside with PBS(-). Remaining PBS(-) was removed from inside and outside of tissue insert. The tissue inserts were transferred into the upper wells of new 6-well pates filled with 0.9 mL/well of fresh medium.
- Observable damage in the tissue due to washing: Not reported

MTT DYE USED TO MEASURE TISSUE VIABILITY AFTER TREATMENT / EXPOSURE
PRE-TEST
- MTT concentration: 30µL / mL MTT medium
- Incubation time: 60 minutes
NYLON MESH
- 30µl of test substance was dropped onto a nylon mesh on a glass slide. After 60 minutes at room temp., the corrosion of the nylon mesh was evaluated microscopically. Corrosion was not observed.
MAIN TST
-MTT concentration: 0.3 mL/well of MTT medium
-Incubation time: 180+- 5 minutes
- Spectrophotometer: Multimode Microplate Reader (FlUOstar Omega, BMG LABTECH) at 570 nm


FUNCTIONAL MODEL CONDITIONS WITH REFERENCE TO HISTORICAL DATA
- Viability positive control: Mean ± SD: 2.0 ± 0.3 %; Minimum: 1.3 %; Maximum: 2.6 %
- OD negative control: Mean ± SD: 2.071 ± 0.196; Minimum: 1.787; Maximum: 2.397
- OD positive control: Mean ± SD: 0.042 ± 0.007; Minimum: 0.024; Maximum: 0.062

NUMBER OF REPLICATE TISSUES: 3; 2 to for tissue-binding test

CONTROL TISSUES USED IN CASE OF MTT DIRECT INTERFERENCE
- Fresh tissues
- N. of replicates : 3
- Method of calculation used: The mean of blank was subtracted from ODs of each tissue inserts and the mean value was calculated in each tissue insert to obtain PD of each tissue insert. The cell viability of each tissue was calculated by the following formula:
Cell viability (%) = (OD of each tissue insert of each treatment group : Mean OD of the negative control substance group) × 100
The mean and standard deviation (SD) of cell viabilities in each treatment group were calculated by the cell viability of each tissue insert.

NUMBER OF INDEPENDENT TEST EXPERIMENTS TO DERIVE FINAL PREDICTION: 2

PREDICTION MODEL / DECISION CRITERIA
- The test substance is considered to be irritant to skin if the viability greater or equal than 50% (UN GHS Category: 1or 2)
- The test substance is considered to be non-irritant to skin if the viability is less than 50% (UN GHS Category: not classified)

Control samples:

yes, concurrent negative control

yes, concurrent positive control

Amount/concentration applied:

TEST MATERIAL/CONTROLS:
- Amount applied: 30 µL

Duration of treatment / exposure:

-test substance applied onto each tissue surface at 1 minutes interval

Duration of post-treatment incubation (if applicable):

After the last tissue insert was exposed, all plates were incubated for 35 ± 1 minutes.
All plates were taken out of the incubator and placed at room temperature until 60 ± 1 minutes was completed for the first exposed tissue insert.

Number of replicates:

3

Test animals

Species:

other: EpiDerm tissue

Strain:

not specified

Details on test animals or test system and environmental conditions:

TEST KIT
- Source: MatTek Corporation
- Receipt date: 2019-07-29

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 37
- Humidity (%): humid conditions

Test system

Type of coverage:

not specified

Preparation of test site:

not specified

Vehicle:

not specified

Controls:

yes, concurrent positive control

yes, concurrent negative control

Amount / concentration applied:

TEST MATERIAL/NEGATIVE CONTROL/POSITIVE CONTROL
- Amount(s) applied: 30 µL

Duration of treatment / exposure:

1 minute

Observation period:

After the last tissue insert was exposed, all plates were incubated for 35 ± 1 minutes.
All plates were taken out of the incubator and placed at room temperature until 60 ± 1 minutes was completed for the first exposed tissue insert.

Number of animals:

n/a

Results and discussion

In vitro

Results

Irritation / corrosion parameter:

% tissue viability

Value:

5.3

Vehicle controls validity:

not applicable

Negative controls validity:

valid

Positive controls validity:

valid

Remarks on result:

positive indication of irritation

Remarks:

As a result of skin irritation test, the cell viability treated by DPNG was 5.3%, falling below 50% which the judgement criteria of skin irritation.

Other effects / acceptance of results:

ACCEPTANCE OF RESULTS:
- Acceptance criteria met for negative/positive control: The mean OD in the negative control substance was 1.823. The mean cell viability in the positive control substance was 2.0%.
- Acceptance criteria met for variability between replicate measurements: The SDs of cell viabilities in the negative and the positive control substances, and the test substance were 6.7%, 0.2% and 2.7%, respectively.
- Range of historical values: Cell viability positive control [%]: 2.0 ± 0.3

Any other information on results incl. tables

As a result of tissue-binding test, the staining ratio was 0.2%, it was < 5%. Therefore, correction of OD was not conducted.

The mean OD in the negative control substance was 1.823. The mean cell viability in the positive control substance was 2.0%. The SDs of cell viabilities in the negative and the positive control substances, and the test substance were 6.7%, 0.2% and 2.7%, respectively. These results indicated that the present study was appropriately performed.

As a result of skin irritation test, the cell viability treated by DPNG was 5.3%, falling below 50% which the judgement criteria of skin irritation.

Applicant's summary and conclusion

Interpretation of results:

Category 2 (irritant) based on GHS criteria

Remarks:

As a result of skin irritation test, the cell viability treated by DPNG was 5.3%, falling below 50% which the judgement criteria of skin irritation.

Conclusions:

It was concluded that DPNG was "Irritant" (UN GHS Category 1 or 2) under the present test conditions.