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Administrative data

Endpoint:
skin irritation: in vitro / ex vivo
Type of information:
experimental study
Adequacy of study:
key study
Study period:
2016-06-29 to 2016-07-01
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2017
Report date:
2017

Materials and methods

Test guidelineopen allclose all
Qualifier:
according to guideline
Guideline:
OECD Guideline 439 (In Vitro Skin Irritation: Reconstructed Human Epidermis Test Method)
Version / remarks:
2015
Deviations:
no
Qualifier:
according to guideline
Guideline:
EU Method B.46 (In Vitro Skin Irritation: Reconstructed Human Epidermis Model Test)
Version / remarks:
2012
GLP compliance:
yes (incl. QA statement)

Test material

Constituent 1
Chemical structure
Reference substance name:
Sodium 4-morpholin-1-ylethylsulphonate
EC Number:
275-203-2
EC Name:
Sodium 4-morpholin-1-ylethylsulphonate
Cas Number:
71119-23-8
Molecular formula:
C6H13NO4S.Na
IUPAC Name:
sodium 4-morpholin-1-ylethylsulphonate
Test material form:
solid: particulate/powder

In vitro test system

Test system:
human skin model
Source species:
human
Cell type:
non-transformed keratinocytes
Vehicle:
unchanged (no vehicle)
Details on test system:
TISSUE
- Model used: EPISKIN(TM) Small Model (SM)
- Tissue batch number: 16-EKIN-026
- Date of initiation of testing: 29.06.2016

TEMPERATURE USED FOR TEST SYSTEM
- Temperature used during treatment / exposure: room temperature
- Temperature of post-treatment incubation: 37 °C for 42 hours

REMOVAL OF TEST MATERIAL AND CONTROLS
-Volume and number of washing steps: 25 mL PBS solution used to thoroughly rinse the tissue once
- Observable damage in the tissue due to washing: none
- Modifications to validated SOP: none

MTT DYE USED TO MEASURE TISSUE VIABILITY AFTER TREATMENT / EXPOSURE
- MTT concentration: 2 mL of 0.3 mg/mL MTT per well
- Incubation time: 3 hours +/- 5 min
- Spectrophotometer: not specified
- Wavelength: 570 nm

FUNCTIONAL MODEL CONDITIONS
- Morphology: well-differentiated epidermis consisting of a basal layer, several spinous and granular layers and a thick stratum corneum
- Contamination: absence of bacteria, fungus and mycoplasma

NUMBER OF REPLICATE TISSUES: 3

CONTROL TISSUES USED IN CASE OF MTT DIRECT INTERFERENCE: no direct MTT interference

NUMBER OF INDEPENDENT TEST SEQUENCES / EXPERIMENTS TO DERIVE FINAL PREDICTION: 1

PREDICTION MODEL / DECISION CRITERIA
- A test item is identified as requiring classification and labelling according to UN GHS (Category 2 or Category 1), if the mean relative viability after 15 minutes exposure and 42 hours post incubation is less or equal (≤) to 50 % of the negative control.
Control samples:
yes, concurrent negative control
yes, concurrent positive control
Amount/concentration applied:
TEST MATERIAL
- Amount applied: 10 mg (to moistened skin)

NEGATIVE CONTROL
- Amount applied: 10 µL

POSITIVE CONTROL
- Amount applied: 10 µL
- Concentration: 5 % aq.
Duration of treatment / exposure:
15 minutes
Duration of post-treatment incubation (if applicable):
42 hours
Number of replicates:
3

Results and discussion

In vitro

Results
Irritation / corrosion parameter:
% tissue viability
Run / experiment:
1
Value:
116
Vehicle controls validity:
not applicable
Negative controls validity:
valid
Remarks:
100 %
Positive controls validity:
valid
Remarks:
18 %
Other effects / acceptance of results:
- OTHER EFFECTS:
- Visible damage on test system: no
- Direct-MTT reduction: No colour change was observed after three hours of incubation. The test material did not interact with the MTT, therefore additional controls and data calculations were not necessary. A false estimation of viability can be precluded.
- Colour interference with MTT: The test item showed no ability to become coloured in contact with water. The intrinsic colour of test item is white and therefore considered to be not able to significantly stain the tissues and lead false estimate of viability. Furthermore, the test item was completely removed from the epidermal surface at rinsing period. Additional controls and data calculations were not necessary. A false estimation of viability can be precluded.

ACCEPTANCE OF RESULTS:
- Acceptance criteria met for negative control: yes
- Acceptance criteria met for positive control: yes
- Acceptance criteria met for variability between replicate measurements: yes

Applicant's summary and conclusion

Interpretation of results:
GHS criteria not met
Conclusions:
In an experimental study according to OECD TG 439 under GLP conditions, the test substance did not reduce cell viability. Therefore, it is considered not irritating to skin.
Executive summary:

A test according to OECD TG 439 has been performed to predict its irritation potential of the test item by measurement of its cytotoxic effect, as reflected in the MTT assay. Triplicates of the human skin model EPISKIN (Reconstructed Human Epidermis, SkinEthic Laboratories) were treated with test item and incubated for 15 minutes at room temperature. Exposure of the reconstructed human epidermis skin units with test item was terminated by rinsing with PBS 1x solution. Epidermis units were then incubated at 37 °C for 42 hours in an incubator with 5 % CO2. The viability of each disk was assessed by incubating the tissues for 3 hours with MTT solution at 37 °C in 5 % CO2 protected from light. The precipitated formazan was then extracted using acidified isopropanol and quantified spectrophotometrically.


SDS (5 % aq.) and 1×PBS treated epidermis (three units / positive and negative control) were used as positive and negative controls respectively. For each treated tissue viability was expressed as a percentage relative to negative control.


A test item is identified as requiring classification and labelling according to UN GHS (Category 2 or Category 1), if the mean relative viability after 15 minutes exposure and 42 hours post incubation is less or equal (≤) to 50 % of the negative control. In this in vitro skin irritation test using the EPISKIN model, the test item did not show significantly reduced cell viability in comparison to the negative control (mean value: 116 %). All obtained test item viability results were far above 50 % when compared to the viability values obtained from the negative control. Therefore the test item was considered to be non-irritant to skin.


Positive and negative controls showed the expected cell viability values within acceptable limits. The experiment was considered to be valid. The results obtained from this in vitro skin irritation test, using the EPISKIN model, indicated that the test item reveals no skin irritation potential under the utilised testing conditions.