Registration Dossier

Administrative data

Endpoint:
skin irritation: in vitro / ex vivo
Type of information:
experimental study
Adequacy of study:
key study
Study period:
Aug 08 - Sep 30, 2019
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2019
Report Date:
2019

Materials and methods

Test guidelineopen allclose all
Qualifier:
according to
Guideline:
EU Method B.46 (In Vitro Skin Irritation: Reconstructed Human Epidermis Model Test)
Version / remarks:
Council Regulation (EC) No. 761/2009 laying down test methods pursuant to Regulation (EC) No. 1907/2006 of the European Parliament and the council on the Registration, Evaluation, Authorisation and Restriction of Chemicals (REACH).
Deviations:
no
Qualifier:
according to
Guideline:
OECD Guideline 439 (In Vitro Skin Irritation: Reconstructed Human Epidermis Test Method)
Version / remarks:
2010
Deviations:
no
Qualifier:
according to
Guideline:
other: Skinethic skin irritation test -42bis Standard operating procedure (SOP) 2009
Deviations:
no
GLP compliance:
yes (incl. certificate)

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
solid: crystalline
Specific details on test material used for the study:
TREATMENT OF TEST MATERIAL PRIOR TO TESTING
No pre-treatment; the test item was applied undiluted.

In vitro test system

Test system:
human skin model
Source species:
human
Cell type:
non-transformed keratinocytes
Cell source:
foreskin from a single donor
Justification for test system used:
standard model
Vehicle:
unchanged (no vehicle)
Remarks:
No vehicle used in this study; The test item was applied neat to the tissues.
Details on test system:
CELL CULTURE
- Supplier:SkinEthic Laboratories (Lyon, France)
- Source: human keratinocytes cultured on a polycarbonate filter in conditions which permit their terminal differentiation
- Format: 24 well plate
- Batch: 19-RHE-151


TEMPERATURE USED FOR TEST SYSTEM
- Temperature used during treatment: room temperature
- Temperature of post-treatment incubation: 37°C

REMOVAL OF THE TEST MATERIAL AND CONTROL
After the end of the treatment interval, the residual test item was removed immediately by gently rinsing with a minimum volume of 25 mL PBS using a pipette. Excess PBS was removed by gently shaking the inserts and blotting the bottom with blotting paper.

DYE BINDING METHOD
- Dye used in the dye-binding assay: MTT
- Spectrophotometer:ELx800, BioTek Instruments GmbH, Bad Friedrichshall, Germany at 570 nm
Control samples:
yes, concurrent negative control
Amount/concentration applied:
TEST MATERIAL: 16 mg of solid test material
NEGATIVE CONTROL: 16 µL (Phosphate-Buffered Saline)
POSITIVE CONTROL: 16 µL (5% aqueous solution of sodium dodecyl sulfate in deionised water)
Duration of treatment / exposure:
42 min (± 1 minute)
Duration of post-treatment incubation (if applicable):
42 hours (± 1 hour)
Number of replicates:
3

Results and discussion

In vitro

Results
Irritation / corrosion parameter:
% tissue viability
Run / experiment:
Experiment 1 / Run 1
Value:
86
Vehicle controls validity:
not applicable
Remarks:
The test item was applied neat to the tissues
Negative controls validity:
valid
Positive controls validity:
valid
Remarks on result:
no indication of irritation
Other effects / acceptance of results:
OTHER EFFECTS:
- Visible damage on test system: none
- Direct-MTT reduction: none
- Colour interference with MTT: none

ACCEPTANCE OF RESULTS:
After treatment with the negative control the absorbance values reached a mean OD of 1.697 (SD 4.4%). Therefore, the negative control fulfilled the validity criteria.
Treatment with the positive control revealed a mean relative viability of 1.8% (SD 11.1%), thus the positive control reached the validity criteria.




Any other information on results incl. tables

 Group Time / [min]  Mean OD  Mean Relative viability / [%]
 Negative Control 42  1.697 100 
 Positive Control 42

0.030

1.8

 Test Material

42

1.459

86.0

Applicant's summary and conclusion

Interpretation of results:
GHS criteria not met
Conclusions:
This study was performed according to GLP and the methods applied are fully compliant with OECD TG 439. Under the experimental conditions reported, the test material is not irritating to the skin.
Executive summary:

The objective of the present study was to investigate the potential of the test item to induce skin irritation in an in vitro human skin model.

The information for this endpoint study record was obtained from an experimental study. The OECD GLP criteria were met and the methods applied are fully compliant with OECD TG 439. The test item was applied topically to a human reconstructed skin model followed by determination of the cell viability. Cell viability was determined by enzymatic conversion of vital dye MTT into a blue formazan salt and measurement of the formazan salt after extraction from tissues. The percent reduction of cell viability in comparison to untreated negative controls was used to predict the skin irritation potential.
Triplicates of the human skin RHE-model were treated with the test item, the negative or the positive control for 42 minutes (± 1 minute). 16 µL of either the negative control (DPBS-buffer) or the positive control (5% aqueous solution of sodium dodecyl sulfate) were applied to the tissues. Before application of 16 mg of the solid test item, 10 µL of deionised water was spread to the epidermis surface to improve the contact between the test item and the epidermis.

All acceptability criteria after treatment with the negative control (DPBS-buffer) and the positive control (5% aqueous solution of sodium dodecyl sulfate) were met.
Following treatment with the test item, the tissue viability was 86.0 % and, thus, higher than 50%, i.e. according to OECD 439 the test item is considered as non-irritant to skin (UN GHS: No Category).

Under the conditions of the present study, the test item is not considered to possess an irritant potential to skin (UN GHS: No Category).