3,7-dimethyloct-1-en-3-yl acetate

Skin irritation / corrosion

Administrative data

Endpoint:

skin irritation: in vitro / ex vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

03 June 2015 to 29 June 2015

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2015

Report date:

2015

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

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

Version / remarks:

July 26, 2013

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

3,7-dimethyloct-1-en-3-yl acetate

EC Number:

269-847-3

EC Name:

3,7-dimethyloct-1-en-3-yl acetate

Cas Number:

68345-17-5

Molecular formula:

C12H22O2

IUPAC Name:

3,7-dimethyloct-1-en-3-yl acetate

Test material form:

liquid

In vitro test system

Test system:

human skin model

Source species:

human

Cell type:

non-transformed keratinocytes

Cell source:

other: EpiDerm™ tissue

Source strain:

other: human-derived epidermal keratinocytes

Justification for test system used:

The OECD Guideline 439 assay is based on reconstructed human epidermis (RhE).

Vehicle:

unchanged (no vehicle)

Details on test system:

RECONSTRUCTED HUMAN EPIDERMIS (RHE) TISSUE
- Model used: EpiDerm™ tissue
- Tissue batch number: Lot No.: 21677
- Delivery date: June 23, 2015
- Date of initiation of testing: On day of receipt the preincubation phase of the EpiDerm™ tissues started.


TEMPERATURE USED FOR TEST SYSTEM
- Temperature used during treatment / exposure: 37 ± 1.5 °C
- Temperature of post-treatment incubation: 42 h

REMOVAL OF TEST MATERIAL AND CONTROLS
-Volume and number of washing steps:
After the end of the treatment interval the inserts were removed immediately from the 6-well plate and tissues were gently rinsed with DPBS at least 15 times in order to remove any residual test material. After the rinsing the inserts were submerged in DPBS at least three times. Afterwards the inserts were once again rinsed with sterile DPBS from the inside and the outside. Excess DPBS was removed by gently shaking the inserts and blotting the bottom with sterile blotting paper.


MTT DYE USED TO MEASURE TISSUE VIABILITY AFTER TREATMENT / EXPOSURE
- MTT concentration: 1 mg/mL
- Incubation time: 3 h
- Spectrophotometer: Versamax® Molecular Devices, Softmax Pro, version 4.7.1
- Wavelength: 570 ± 1 nm


NUMBER OF REPLICATE TISSUES: 3

CONTROL TISSUES USED IN CASE OF MTT DIRECT INTERFERENCE
not required: The colour of test item/water mixture did not change during the incubation period compared with the colour of the pure test item. Therefore, the measurement of the OD of the test item in water at 570 nm was not required and consequently not performed.

NUMBER OF INDEPENDENT TEST SEQUENCES / EXPERIMENTS TO DERIVE FINAL PREDICTION: 1

PREDICTION MODEL / DECISION CRITERIA
- The test substance is considered to be irritant or corrosive to skin if the mean tissue viability is less than or equal to 50%.

Control samples:

yes, concurrent negative control

Amount/concentration applied:

TEST MATERIAL
30 µL (47 µL/cm2 according to guideline) of the undiluted test item was dispensed directly atop the EpiDerm™ tissue and spread to match the surface of the tissue for a complete treatment time of 60 minutes.

NEGATIVE CONTROL
30 µL DPBS (MatTek) was used as negative control per tissue.

POSITIVE CONTROL
30 µL of a 5% SLS solution in deionised water (MatTek) was used a positive control per tissue.

Duration of treatment / exposure:

60 min

Duration of post-treatment incubation (if applicable):

42 h

Number of replicates:

3

Results and discussion

In vitro

Results

Irritation / corrosion parameter:

% tissue viability

Run / experiment:

1

Value:

112.5

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:

Criterion 1 (negative control): The absolute OD 570 nm of the negative control tissues in the MTT test is an indicator of tissue viability obtained after the shipping and storing procedure and under specific conditions of the assay. Tissue viability is meeting the acceptance criterion if the mean OD570 of the negative control tissues is ≥ 0.8 and ≤ 2.8.
Criterion 2 (positive control): An assay is meeting the acceptance criterion if mean relative tissue viability of the positive control is ≤ 20%.
Criterion 3: Rel. standard deviation: The SD of 3 identical replicates should be < 18%. OD values should not be below historically established boundaries. Historical data and the quality certificate of the supplier of the test kit demonstrated the robustness of the test system or rather of the test kit.

Any other information on results incl. tables

Table 1: Results after treatment (60 min) with Dimethyl Octenyl Acetate (DMOE-Ac) and the controls

	Mean Absorbance of 3 Tissues	Relative Standard Deviation [%]	Mean Rel. Absorbance [% of Negative Control]
Negative control	1.792	4.1	100
Positive control	0.096	13.7	5.4
Test item	2.016	16.8	112.5

 

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

Dimethyl Octenyl Acetate (DMOE-Ac) is not irritant to skin according to UN GHS.

Executive summary:

This in vitro study was performed to assess the irritation potential of Dimethyl Octenyl Acetate (DMOE-Ac) by means of the Human Skin Model Test. The test item did not reduce MTT (test for direct MTT reduction), and it did not change colour when mixed with deionised water (test for colour interference). Also its intrinsic colour was not intensive. Consequently, additional tests with freeze-killed or viable tissues were not necessary. Each three tissues of the human skin model EpiDerm™ were treated with the test item, the negative or the positive control for 60 minutes. 30 µL of the test item were applied to each tissue, and spread to match the surface of the tissue. 30 µL of either the negative control (DPBS) or the positive control (5% SLS) were applied to each tissue. After treatment with the negative control the absorbance values were well in the required range of the acceptability criterion of mean OD ≥ 0.8 and ≤ 2.8 for the 60 minutes treatment interval, thus assuring the quality of the tissues. Treatment with the positive control induced a sufficient decrease in the relative absorbance as compared to the negative control for the 60 minutes treatment interval, and thus assuring the validity of the test system. After treatment with the test item the mean relative absorbance value was 112.5% compared to the relative absorbance value of the negative control. This value is above the threshold for irritancy of ≤ 50%. Therefore, the test item is not considered to possess an irritant potential. In conclusion, it can be stated that in this study and under the experimental conditions reported, Dimethyl Octenyl Acetate (DMOE-Ac) is not irritant to skin.