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Description of key information

Corrosive to skin, Category 1B.

Key value for chemical safety assessment

Skin irritation / corrosion

Link to relevant study records
Reference
Endpoint:
skin irritation: in vitro / ex vivo
Type of information:
experimental study
Adequacy of study:
key study
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study
Qualifier:
according to guideline
Guideline:
OECD Guideline 431 (In Vitro Skin Corrosion: Reconstructed Human Epidermis (RHE) Test Method)
Deviations:
no
GLP compliance:
yes
Test system:
human skin model
Source species:
human
Vehicle:
unchanged (no vehicle)
Details on test system:
EPISKIN™ Reconstructed Human Epidermis Model Kit
Supplier : MatTek
Date received : 24 May 2016
EpiSkinTM Tissues (0.38cm2) lot number : 23338
Maintenance Medium lot number : 051916TMA
Control samples:
yes, concurrent negative control
yes, concurrent positive control
Amount/concentration applied:
50 uL
Duration of treatment / exposure:
3 minutes
60 minutes
Duration of post-treatment incubation (if applicable):
3 hours
Number of replicates:
3
Irritation / corrosion parameter:
% tissue viability
Run / experiment:
3 minutes
Value:
61.6
Negative controls validity:
valid
Positive controls validity:
valid
Irritation / corrosion parameter:
% tissue viability
Run / experiment:
60 minutes
Value:
2.6
Negative controls validity:
valid
Positive controls validity:
valid

Tissue

Exposure Period

Mean OD562of individual tissues (tvt)

Mean OD562of duplicate tissues

Corrected OD562of tissues (tvt -[tktukt])

Standard Deviation

Coefficient of Variation (%)

Relative Mean Viability (%)

Negative Control

3 Minutes

1.720

1.835

 

0.162

8.8

100*

1.949

 

60 Minutes

1.872

1.838

 

0.048

2.6

1.804

 

Positive Control

3 Minutes

0.100

0.094

 

0.009

N/A

5.1

0.087

 

60 Minutes

0.090

0.087

 

0.005

N/A

4.7

0.083

 

Test Item

3 Minutes

1.347

1.415

1.130

0.095

6.7

61.6

1.482

60 Minutes

0.562

0.409

0.048

0.216

N/A

2.6

0.256

3 minute exposure corrected mean OD562= 0.412 (tkt) – 0.127 (ukt) = 0.285

60 minute exposure corrected mean OD562= 0.474 (tkt) – 0.113 (ukt) = 0.361

tvt = treated viable tissues

tkt = treated killed tissues

ukt = untreated killed tissues

Interpretation of results:
Category 1B (corrosive) based on GHS criteria
Conclusions:
The test item was considered to be corrosive to the skin.
Executive summary:

Introduction

The purpose of this test is to evaluate the corrosivity potential of the test item using the EpiDerm™ Human Skin Model after treatment periods of 3 and 60 minutes.

Corrosion is directly related to cytotoxicity in the EpiDerm™ tissue. Cytotoxicity is determined by the reduction of MTT (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl-tetrazolium bromide) to formazan by viable cells in the test item treated tissues relative to the corresponding negative control. The results are used to make a prediction of the corrosivity potential of the test item.

Methods

Duplicate tissues were treated with the test item for exposure periods of 3 and 60 minutes. The test item was found to directly reduce MTT and therefore additional non-viable tissues were incorporated into the testing for correction purposes. Negative and positive control groups were treated for each exposure period. At the end of the exposure period the test item was rinsed from each tissue before each tissue was taken for MTT-loading. After MTT loading each tissue was placed in 2 mL Isopropanol for MTT extraction.

At the end of the formazan extraction period each well was mixed thoroughly and triplicate 200 μL samples were transferred to the appropriate wells of a pre-labeled 96-well plate. The optical density (OD) was measured at 562 nm (OD562).

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

Results

The relative mean viabilities for each treatment group were as follows:

Exposure Period                                         Percentage Viability

Negative Control       Positive Control       Test Item

3 minute                     100*                                   5.1                     61.6

60 minute                    100*                                   4.7                     2.6

*The mean viability of the negative control tissues is set at 100%

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

Conclusion

The test item was considered to be corrosive to the skin.

Endpoint conclusion
Endpoint conclusion:
adverse effect observed (corrosive)

Additional information

Justification for classification or non-classification