Butanedioic acid, 2-hydroxy-, 1,4-bis[5,7,7-trimethyl-2-(1,3,3-trimethylbutyl)octyl] ester

Skin irritation / corrosion

Administrative data

Endpoint:

skin irritation / corrosion

Remarks:

in vitro

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2015-04-13 to 2015-06-02

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: see 'Remark'

Remarks:

The study conducted according to the Commission Regulation (EC) No 440/2008, Annex Part B, B.40.Bis: “In Vitro Skin Corrosion: Human Skin Model Test”, Official Journal of the European Union No. L142 (31 May 2008) OECD Guidelines for the Testing of Chemicals, No. 431, “In Vitro Skin Corrosion: Reconstructed Human Epidermis (RHE) Test Method” (26 September 2014)

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

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

1,4-bis[2-(4,4-dimethylpentan-2-yl)-5,7,7-trimethyloctyl] 2-hydroxybutanedioate

EC Number:

807-422-1

Cas Number:

66918-01-2

Molecular formula:

C40H78O5

IUPAC Name:

1,4-bis[2-(4,4-dimethylpentan-2-yl)-5,7,7-trimethyloctyl] 2-hydroxybutanedioate

Test animals

Species:

other: Human skin: EpiSkin- SM Kit supplied by SkinEthic, France batch No.: 15-EKIN-017

Strain:

other: other: Adult human-derived epidermal keratinocytes

Test system

Type of coverage:

other: in vitro test

Preparation of test site:

other: in vitro test

Vehicle:

unchanged (no vehicle)

Controls:

other: in vitro test

Amount / concentration applied:

- 50 μL of test item was applied evenly to each of two test units and two additional colour control skin units.
- 50 μL of physiological saline was added to each of the two negative control skin units.
- 50 μL of glacial acetic acid was added to each of the two positive control skin units.

Duration of treatment / exposure:

The plates with the treated epidermis units were incubated for 4 hours (±10 min) at room temperature (23.2-24.6°C) covered with the plate lids. after rincing, the MTT test was performed and cell viability was measured.

Number of animals:

Two test units and two additional colour control skin units + two negative control skin units + two positive control skin units.

Details on study design:

Disks of EPISKIN (two units) were treated with test item and incubated for 4 hours at room temperature. Exposure of test material was terminated by rinsing with Phosphate Buffered Saline solution. The viability of each disk was assessed by incubating the tissues for 3 hours
with MTT solution. The precipitated formazan crystals were then extracted using acidified isopropanol and quantified spectrophotometrically.
Physiological saline (0.9% (w/v) NaCl solution) and glacial acetic acid treated epidermis were used as negative and positive controls, respectively (two units / control). Two additional disks were used to provide an estimate of colour contribution from the test item. For each treated tissue viability was expressed as a % relative to the negative control. If the mean relative viability after 4 hours of exposure is below 35% of the negative control, the test item is considered to be corrosive to skin.
Following exposure with test item, the mean cell viability was measured compared to the negative control. If above the threshold of 35%, the test item is considered as being non-corrosive.

Results and discussion

In vivo

Results

Results 1

Irritation parameter:

other: Relative absorbance (% of Negative Control)

Basis:

other: Mean negative control

Time point:

other: 4 hours

Score:

100

Results 2

Irritation parameter:

other: Relative absorbance (% of Negative control)

Basis:

other: Mean Positive control

Time point:

other: 4 hours

Score:

1.7

Results 3

Irritation parameter:

other: Relative absorbance (% Negative Control)

Basis:

other: Mean test item

Time point:

other: 4 hours

Score:

102.5

Irritant / corrosive response data:

Following exposure with Bis[2-(4,4-dimethylpentan-2-yl)-5,7,7-trimethyloctyl] malate, the mean cell viability was 102.5% compared to the negative control. This is above the threshold of 35%, therefore the test item was considered as being non-corrosive. The experiment met the validity criteria, therefore the study was considered to be valid.

Applicant's summary and conclusion

Interpretation of results:

not irritating

Remarks:

Migrated information Not corrosive to the skin Criteria used for interpretation of results: EU

Conclusions:

In conclusion, in this in vitro EPISKIN model test with Bis[2-(4,4-dimethylpentan-2-yl)-5,7,7-trimethyloctyl] malate, the results indicate
that the test item is not corrosive to the skin.

Executive summary:

An in vitro skin corrosivity test of Bis[2-(4,4-dimethylpentan-2-yl)-5,7,7- trimethyloctyl] malate test item was performed in a reconstructed human epidermis model. EPISKIN-SM is designed to predict and classify the corrosive potential of

chemicals by measuring its cytotoxic effect as reflected in the MTT (3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay . The corrosivity of the test item was evaluated according to the OECD No. 431 guideline.

Disks of EPISKIN (two units) were treated with Bis[2-(4,4-dimethylpentan-2-yl)-5,7,7-trimethyloctyl] malate test item and incubated for 4 hours at room temperature. Exposure of test material was terminated by rinsing with Phosphate Buffered Saline

solution. The viability of each disk was assessed by incubating the tissues for 3 hours with MTT solution. The precipitated formazan crystals were then extracted using acidified isopropanol and quantified spectrophotometrically.

Physiological saline (0.9% (w/v) NaCl solution) and glacial acetic acid treated epidermis were used as negative and positive controls, respectively (two units / control). Two additional disks were used to provide an estimate of colour contribution from the test item. For each treated tissue viability was expressed as a % relative to the negative control. If the mean relative viability after 4 hours of exposure is below 35% of the negative control, the test item is considered to be corrosive to

skin.

Following exposure with Bis[2-(4,4-dimethylpentan-2-yl)-5,7,7-trimethyloctyl] malate, the mean cell viability was 102.5% compared to the negative control. This is above the threshold of 35%, therefore the test item was considered as being non-corrosive. The

experiment met the validity criteria, therefore the study was considered to be valid.

In conclusion, in this in vitro EPISKIN model test with Bis[2-(4,4-dimethylpentan-2-yl)-5,7,7-trimethyloctyl] malate, the results indicate that the test item is not corrosive to the skin.