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Skin irritation / corrosion

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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 guidelineopen allclose all
Qualifier:
according to
Guideline:
OECD Guideline 431 (In Vitro Skin Corrosion: Human Skin Model Test)
Deviations:
no
Qualifier:
according to
Guideline:
EU Method B.40 (In Vitro Skin Corrosion: Transcutaneous Electrical Resistance Test (TER))
Deviations:
no
GLP compliance:
yes (incl. certificate)

Test material

Reference
Name:
Unnamed
Type:
Constituent

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

Resultsopen allclose all
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
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
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 EPISKINTMin 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 EPISKINTMmodel 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 EPISKINTMmodel can be used for classification and labelling. The EPISKINTMmodel 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.