2-Heptanol, 3,6-dimethyl-

Skin irritation / corrosion

Administrative data

Endpoint:

skin irritation / corrosion

Remarks:

in vitro

Type of information:

experimental study

Adequacy of study:

key study

Study period:

from 8th to 9th of May, 2013

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP, Guideline study without deficiencies.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2013

Report date:

2013

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 431 (In Vitro Skin Corrosion: Human Skin Model Test)

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method B.40 (In Vitro Skin Corrosion: Transcutaneous Electrical Resistance Test (TER))

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

3,6-dimethylheptan-2-ol

EC Number:

801-829-8

Cas Number:

1247790-47-1

Molecular formula:

C9H20O

IUPAC Name:

3,6-dimethylheptan-2-ol

Test animals

Species:

other: reconstructed human epidermis model

Test system

Vehicle:

unchanged (no vehicle)

Controls:

other: tissues were treated with the negative control material

Amount / concentration applied:

TEST MATERIAL
- Amount(s) applied (volume or weight with unit): 50 µl of the test material was applied topically to the corresponding tissues ensuring uniform coverage of the tissues.

Duration of treatment / exposure:

Duplicate tissues were treated with the test material for exposure periods of 3, 60 and 240 minutes. Duplicate tissues were treated with the positive
and negative control materials for an exposure period of 240 minutes.

Observation period:

Not applicable

Number of animals:

Not applicable

Details on study design:

The procedure followed is based on the recommended EpiSkin™ Skin Corrosivity Test protocol INVITTOX N°118.

Preparation of Test Item: The test item was used as supplied.

NEGATIVE AND POSITIVE CONTROLITEMS
Negative control item: 0.9% w/v sodium chloride solution
Positive control item: Glacial Acetic acid

REMOVAL OF TEST SUBSTANCE
At the end of each exposure period, each tissue was removed from the well using forceps and rinsed using a bottle containing Phosphate Buffered Saline Dulbeccos (PBS) with Ca++ and Mg++. Rinsing was achieved by filling and emptying each tissue insert for approximately 40 seconds using a constant soft stream pf PBS to gently remove any residual test item.

INTERPRETATION OF RESULTS:
The corrosivity potential of the test item was predicted from the relative mean tissue viabilities obtained after the 3, 60 and 240-Minute exposure periods, compared to the mean of the negative control tissues (n=2) treated with 0.9% w/v sodium chloride solution.

SCORING SYSTEM:
Classification of corrosivity potential was based on relative viabilities for each exposure time: see table in the following section.

Results and discussion

In vivo

Results

Results 1

Irritation parameter:

other: relative viability percentage of the test item (based on optical density at 540 nm)

Basis:

mean

Time point:

other: 240 minutes

Score:

113.1

Reversibility:

other: not applicable

Results 2

Irritation parameter:

other: relative viability percentage of the test item (based on optical density at 540 nm)

Basis:

mean

Time point:

other: 60 minutes

Score:

134

Reversibility:

other: not applicable

Results 3

Irritation parameter:

other: relative viability percentage of the test item (based on optical density at 540 nm)

Basis:

mean

Time point:

other: 3 minutes

Score:

125.4

Reversibility:

other: not applicable

Any other information on results incl. tables

DIRECT MTT REDUCTION

The MTT solution containing the test item did not turn blue. This was taken to indicate the test item did not reduce MTT.

RESULTS OF TEST ITEM, POSITIVE CONTROL AND NEGATIVE CONTROL ITEM

Mean Optical Density at 540 nm values and viabilities for the negative control, positive control and test item are given in table 1 attached.

QUALITY CRITERIA:

The relative mean tissue viability for the positive control treated tissues was 3.1% relative to the negative control treated tissues following the 240 -Minute exposure period. The positive control acceptance criterion was therefore satisfied.

The mean optical density for the negative control treated tissues was 0.911. The negative control acceptance criterion was therefore satisfied.

Applicant's summary and conclusion

Interpretation of results:

other: Non-Corrosive

Remarks:

Criteria used for interpretation of results: other: OECD 431

Conclusions:

The test item was considered to be Non-Corrosive to the Skin

Executive summary:

The purpose of this test was to evaluate the corrosivity potential of the test material using the EPISKIN^TMin vitro Reconstructed Human Epidermis (RHE) Model after treatment periods of 3, 60 and 240 minutes. This method was designed to meet the be compatible with the OECD Guideline for the Testing of Chemicals No. 431 “In VitroSkin Corrosion: Human Skin Model Test” (adopted 13 April 2004) and the Method B.40 of Commission Regulation (EC) No. 440/2008

The EPISKIN^TMmodel is able to distinguish between corrosive and non-corrosive chemicals for all of the chemical types studied. As stated in regulation 1272/2008/EEC a validatedin vitrotest such asin vitroskin corrosion test in the EPISKIN^TMmodel can be used for classification and labelling. The EPISKIN^TMmodel is also able to distinguish between known R35 (UN packing group I) and R34 (UN packing group II & III) chemicals.

Duplicate tissues were treated with the test material for exposure periods of 3, 60 and 240 minutes. At the end of the exposure period the test material was rinsed from each tissue before each tissue was taken for MTT (3 -[4,5 -dimethylthiazol-2 -yl]-2,5 -diphenyl-tetrazolium bromide) loading. After MTT loading a total biopsy of each epidermis was made and placed into micro tubes containing acidified isopropanol for extraction of formazan crystals out of the MTT-loaded tissues. 

At the end of the formazan extraction period each tube was mixed thoroughly and duplicate 200 µl samples were transferred to the appropriate wells of a pre-labelled 96 -well plate. The optical density (OD) was measured at 540 nm.

Data are presented in the form of percentage viability (MTT reduction in the test item treated tissues relative to negative control tissues).

The relative mean viability of the test material treated tissues was:

240 minutes exposure		113.1%
60 minutes exposure		134.0%
3 minutes exposure		125.4%

The quality criteria required for acceptance of results in the test were satisfied.

The test item was considered to be Non-Corrosive to the skin.