Carboxylic acids, C5-9, triesters with 2-ethyl-2-(hydroxymethyl)propane-1,3-diol

Skin irritation / corrosion

Administrative data

Endpoint:

skin corrosion: in vitro / ex vivo

Remarks:

in vitro

Type of information:

experimental study

Remarks:

The two substances share structural similarities with common functional groups, esters, and side chains varying in their length. Moreover, the side chains are chemically simple structures which are closely related to substances of known low toxicity.

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: The study has been conducted in according to OECD guideline and GLP without deviation

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:

other: B.40 BIS (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:

2-ethyl-2-[[(1-oxononyl)oxy]methyl]propane-1,3-diyl dinonan-1-oate

EC Number:

204-793-6

EC Name:

2-ethyl-2-[[(1-oxononyl)oxy]methyl]propane-1,3-diyl dinonan-1-oate

Cas Number:

126-57-8

Molecular formula:

C33H62O6

IUPAC Name:

2,2-bis[(nonanoyloxy)methyl]butyl nonanoate (non-preferred name)

Test material form:

other: oil

Details on test material:

- Name of test material : TRIMETILOLPROPANO TRIPELARGONATO
- Molecular formula : C33H62O6
- Molecular weight :554.85 g/mol
- Analytical purity: > 99%
- Composition of test material, percentage of components: Nonanoic acid, 1,1'-[2-ethyl-2-[[(1-oxononyl)oxy]methyl]- 1,3-propanediyl] ester
- Lot/batch No.:P_F54 + P_MAGGIO 2013
- Expiration date of the lot/batch: Nov. 2014
- Storage condition of test material: The test item was stored in a closed vessel at room temperature, protected from light.
- Appearance: clear light-yellowish oil

Test animals

Species:

human

Strain:

other: Commercially available Epi-200-Kit.

Details on test animals or test system and environmental conditions:

Epi-200 tissues were procured from MatTek In Vitro Life Science Laboratories.
Day of delivery: 08. Oct. 2013
Batch EPI-200-CORR: 18381

Chemicals and Media:
- MTT reagent: Contains 1mg/mL 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazoliumbromide, which can be reduced to a blue formazan. Prepared as concentrate (5mg/mL in DPBS buffer, stored at -20 °C).
For the pre-test, the concentration was thawed and diluted with serum-free MEM medium directly before use.
For the main study, the concentrate was thawed and diluted with assay medium directly before use.

Isopropanol 99,9%, batch 3100602 used as exctracting solvent for formazan

Test system

Details on study design:

The EpiDerm tissu consists of normal, human-derived epidermal keratinocytes which have been cultured to form a multi-layered, highly differentiated model of the human epiderms. It consists of organised basal, spinous and granular layers, and a multi-layered stratum corneum containing intercellular lamellar lipid layers arranged in patterns analogous to those found in vivo. The EpiDerm tissues are cultured on specially prepared cell cultures inserts. Negative control: Deionised H2O Positive control: KOH, solution in deionised H2O containing 8.0 mol/L

Results and discussion

In vitro

Results

Irritation / corrosion parameter:

dye content (µg/disc)

Value:

ca. 98.1

Vehicle controls validity:

valid

Negative controls validity:

valid

Positive controls validity:

valid

Remarks on result:

no indication of irritation

In vivo

Irritant / corrosive response data:

The photometric absorption of the negative controls was considered as 100 %. For the mean of the three replicates of test item and positive control. formazan production was calculated as % photometric absorption compared with the negative control.
See table below for assessment

Any other information on results incl. tables

Assessment:

% Formazan productionafter 3 min. incubation time	% Formazan productionafter 1 h incubation time	Assessment
< 50% of negative control	irrelevant	Corrosive!
> = 50% of negative control	< 15% of negative control	Corrosive!
>= 50% of negative control	>= 15% of negative control	not corrosive

Results:

The absorption values of negative control, test item and positive control are given in the following table:

Negative Control		Test Item		Positive Control			Incubation time
Tissue 1	Tissue 2	Tissue 1	Tissue 2	Tissue 1	Tissue 2
2.202	1.956	2.067	2.075	0.443	0.472		3 min
2.199	1.975	2.048	2.026	0.452	0.465		3 min
2.166	2.074	2.038	2.079	0.452	0.459		3 min
1.948	2.014	1.716	1.875	0.199	0.205		1 hour
1.986	1.924	1.750	1.916	0.198	0.203		1 hour
1.986	2.016	1.756	1.909	0.194	0.204		1 hour
Mean		Mean		Mean
2.095		2.056		0.457			3 min
1.979		1.820		0.201			1 hour

Validity:

The criterion for optical density of the negative control (> 0.8) was fulfilled: optical density was 2.095 (3 minutes) resp. 1.979 (1 hour). The positive control showed a clear corrosive effect: the value of the three-minuteexperiment was 21.8 % and the value of the one-hour-experiment was 10.1 %. Values for negative control and for positive control were within the range of historical data of the test facility (see Annex 2: Comparison with Historical Data, page 17). Therefore, the experiment is considered valid.

Discussion:

The test item is considered not corrosive. After three minutes treatment, the relative absorbance values were decreased to 98.1 %. This value is well above the threshold for corrosivity (50 %). After one hour treatment relative absorbance values were reduced to 92.0 %. This value is well above the threshold for corrosivity (15 %). In the guideline, values greater or equal to the threshold are considered as “non-corrosive to skin”. The values of the negative control were well above the required acceptability criterion of mean OD > 0.8 for both treatment intervals thus showing the quality of the tissues. The positive control induced a decrease in the relative absorbance as compared to the negative control to 21.8 % for the three minutes treatment interval and 10.1 % for the one hour treatment interval thus ensuring the validity of the test system. For these reasons, the result of the test is considered valid.

Applicant's summary and conclusion

Interpretation of results:

study cannot be used for classification

Remarks:

Migrated information

Conclusions:

Trimetilolpropano tripelargonato is considered as "not corrosive in the human Skin Model Test"

Executive summary:

The study was followed in according to OECD guideline and GLP without significate deviations.

Two tissues of the human skin model EpiDermTM were treated with TRIMETILOLPROPANO TRIPELARGONATO for three minutes and one hour, respectively. 50 μL of the liquid test item were applied to each tissue and spread to match the tissue size. Deionised water was used as negative control, 8M KOH was used as positive control. After treatment, the respective substance was rinsed from the tissue; then, cell viability of the tissues was evaluated by addition of MTT which can be reduced to a blue formazan. Formazan production was measured by measuring the optical density (OD) of the resulting solution. After treatment with the negative control, the absorbance values were well above the required acceptability criterion of mean OD > 0.8 for both treatment intervals thus showing the quality of the tissues. The positive control showed clear corrosive effects for both treatment intervals. After three minutes treatment with the test item, the relative absorbance values were reduced to 98.1 %. This value is well above the threshold for corrosion potential (50 %). After one hour treatment, relative absorbance values were reduced to 92.0 %. This value, too, is well above the threshold for corrosion potential (15 %). In the guideline, values greater or equal to the threshold are considered as “non-corrosive to skin”.

In according to the OECD guideline 431, TRIMETILOLPROPANO TRIPELARGONATO is considered as “not corrosive in the Human Skin Model Test”.