Fatty acids, C10-12, esters with polylactic acid, sodium salts

Skin irritation / corrosion

Administrative data

Endpoint:

skin corrosion: in vitro / ex vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

18 - 21 October 2011

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2011

Report date:

2012

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

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

GLP compliance:

yes (incl. QA statement)

Remarks:

Landesamt für Umwelt, Wasserwirtschaft und Gewerbeaufsicht, Kaiser-Friedrich-Str. 7, 55116 Mainz, Germany

Test material

Test material information

1

Reference substance name:

Fatty acids, C10-12, esters with polylactic acid, sodium salts

EC Number:

700-937-1

Cas Number:

1312021-45-6

Molecular formula:

not available

IUPAC Name:

Fatty acids, C10-12, esters with polylactic acid, sodium salts

Test material form:

liquid: viscous

In vitro test system

Test system:

human skin model

Source species:

human

Cell type:

non-transformed keratinocytes

Cell source:

other: EpiDerm (EPI-200)

Justification for test system used:

The test material is applied topically to a three dimensional human skin model. The skin corrosion test refers to the production of irreversible tissue damage in the skin following the application of a test material on a human skin model. The model allows identification of corrosive chemical substances and mixtures.

Vehicle:

water

Details on test system:

RECONSTRUCTED HUMAN EPIDERMIS (RHE) TISSUE
- Model used: EpiDerm, Epi-200-Kit. The EpiDerm tissue consists of normal, human-derived epidermal keratinocytes which have been cultured to form a multi-layered, highly differenciated model of the human epidermis.
- Tissue vendor: MatTek Corporation in Ashland, USA
- Tissue batch number(s): 15650
- Delivery date: 19 Oct 2011
- Date of initiation of testing: 21 Oct 2011

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

REMOVAL OF TEST MATERIAL AND CONTROLS
-Volume and number of washing steps: thoroughly rinsed with phosphate buffered saline (PBS) and blotted with sterile cellulose tissue

MTT DYE USED TO MEASURE TISSUE VIABILITY AFTER TREATMENT / EXPOSURE
- MTT concentration: 1mg/mL
- Incubation time: 3 h
- Wavelength: 570 nm

NUMBER OF REPLICATE TISSUES: 2

NUMBER OF INDEPENDENT TEST SEQUENCES / EXPERIMENTS TO DERIVE FINAL PREDICTION: 2

PREDICTION MODEL / DECISION CRITERIA (choose relevant statement)
- The test substance is considered to be corrosive to skin if the viability after 3 minutes exposure is less than 50%, or if the viability after 3 minutes exposure is greater than or equal to 50 % and the viability after 1 hour exposure is less than 15%.]
- The test substance is considered to be non-corrosive to skin if the viability after 3 minutes exposure is greater than or equal to 50% and the viability after 1 hour exposure is greater than or equal to 15%.

Control samples:

yes, concurrent negative control

yes, concurrent vehicle

Amount/concentration applied:

In average 25.6 mg

Duration of treatment / exposure:

3 minutes / 1 h

Number of replicates:

2

Results and discussion

In vitro

Results

Results 1

Irritation / corrosion parameter:

other: relative absorbance / optical density (OD)

Remarks:

mean value of 2 tissues

Run / experiment:

3 minutes

Value:

2.103

Vehicle controls validity:

valid

Negative controls validity:

not applicable

Positive controls validity:

valid

Results 2

Irritation / corrosion parameter:

other: relative absorbance / optical density (OD)

Remarks:

mean value of 2 tissues

Run / experiment:

1 h

Value:

0.408

Vehicle controls validity:

valid

Negative controls validity:

not applicable

Positive controls validity:

valid

Other effects / acceptance of results:

ACCEPTANCE OF RESULTS:
- Acceptance criteria met for negative control: The criterion for optical density of the negative control (> 0.8) was fulfilled: optical density was 2.109 (3 minutes) and 1.855 (1 h).
- Acceptance criteria met for positive control: The positive control showed a clear corrosive effect: the value of the 3 minutes experiment was 21.5% and the value of the 1 h experiment was 14.7%.
- Acceptance criteria met for variability between replicate measurements: Values for negative control and for positive control were within the range of historical data of the test facility.

Any other information on results incl. tables

The test item is considered not corrosive since the test item fulfilled the criteria given for non corrosive substances which are:

> 50% of negative control of Formazan production after 3 min. incubation time

> 15% of negative control of Formazan production after 1 h incubation time

Applicant's summary and conclusion

Interpretation of results:

other: not corrosive

Conclusions:

There is regulatory acceptance in the EU that a substance can be considered corrosive (Skin Corrosive Cat. 1, 1A, 1B/C) based on a positive result in the Reconstructed human epidermis test method (in vitro skin corrosion). A negative in vitro corrosivity response is not conclusive with respect to non-classification or classification as a skin irritant and therefore requires further evaluation and/or data generation.