Registration Dossier

Administrative data

Endpoint:
skin irritation: in vitro / ex vivo
Type of information:
experimental study
Adequacy of study:
key study
Study period:
09.10.17-13.10.17
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2018
Report Date:
2018

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 439 (In Vitro Skin Irritation: Reconstructed Human Epidermis Test Method)
Version / remarks:
2015
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:
SOURCE OF TEST MATERIAL
- Source and lot/batch No.of test material: CF1001
- Expiration date of the lot/batch:
- Purity test date:

RADIOLABELLING INFORMATION (if applicable)
- Radiochemical purity:
- Specific activity:
- Locations of the label:
- Expiration date of radiochemical substance:

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material:
- Stability under test conditions:
- Solubility and stability of the test substance in the solvent/vehicle:
- Reactivity of the test substance with the solvent/vehicle of the cell culture medium:

TREATMENT OF TEST MATERIAL PRIOR TO TESTING
- Treatment of test material prior to testing:
- Preliminary purification step (if any):
- Final dilution of a dissolved solid, stock liquid or gel:
- Final preparation of a solid:

FORM AS APPLIED IN THE TEST (if different from that of starting material)

TYPE OF BIOCIDE/PESTICIDE FORMULATION (if applicable)

OTHER SPECIFICS:

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:
commercially available EpiDermTM-Kit.
The EpiDermTM tissue consists of human-derived epidermal keratinocytes which have been cul-tured to form a multi-layered, highly differentiated model of the human epidermis. It consists of organized basal, spinous and granular layers, and a multi-layered stratum corneum containing intercellular lamellar lipid layers representing main
lipid classes analogous to those found in vivo. The EpiDermTM tissues are cultured on specially prepared cell culture inserts.

Origin
EpiDermTM tissues were procured from MatTek In Vitro Life Science Laboratories, Bratislava.
Designation of the kit: EPI-200-SIT
Day of delivery: 10. Oct. 2017
Batch no.: 25848
Control samples:
yes, concurrent negative control
yes, concurrent positive control
yes, concurrent MTT non-specific colour control
Amount/concentration applied:
Amount Test item
#01: 25.0 mg
#02: 25.7 mg
#03: 24.9 mg

Negative control: 30 µL DPBS buffer per tissue
Positive control: 30 µL 5 % SDS solution per tissue
Duration of treatment / exposure:
60 min
Duration of post-treatment incubation (if applicable):
23 h 25 min
Number of replicates:
3

Results and discussion

In vitro

Resultsopen allclose all
Irritation / corrosion parameter:
% tissue viability
Run / experiment:
#01
Value:
90.2
Vehicle controls validity:
not applicable
Negative controls validity:
valid
Positive controls validity:
valid
Remarks on result:
no indication of irritation
Irritation / corrosion parameter:
% tissue viability
Run / experiment:
#02
Value:
96.2
Vehicle controls validity:
not applicable
Negative controls validity:
valid
Positive controls validity:
valid
Remarks on result:
no indication of irritation
Irritation / corrosion parameter:
% tissue viability
Run / experiment:
#03
Value:
94.9
Vehicle controls validity:
not applicable
Negative controls validity:
valid
Positive controls validity:
valid
Remarks on result:
no indication of irritation
Other effects / acceptance of results:
The mean value of relative tissue viability of the test item was reduced to 93.8% after the treat-ment. This value is above the threshold for skin irritation (50%). Therefore, the test item is considered as non-irritant to skin.

Applicant's summary and conclusion

Interpretation of results:
GHS criteria not met
Conclusions:
The test item is considered to be not skin irritant.
Executive summary:

One valid experiment was performed.

Three tissues of the human skin model EpiDermTMwere treated with2,2'-Azobis(2,4-dimethylvaleronitrile)for 60 minutes.

The test item was applied directly to each tissue and spread to match the tissue size (0.63 cm2; as indicated by the supplier).

DPBS-buffer was used as negative control and 5 % SDS solution was used as positive control.

After treatment with the negative control, the mean absorbance value was within the required acceptability criterion of 0.8 ≤ mean OD ≤ 2.8, OD was 1.9. The positive control showed clear irritating effects. The mean value of relative tissue viability was reduced to 1.7% (required:£20 %).

The variation within the tissue replicates of negative, control, positive control and test item was acceptable (required: ≤ 18 %).

 

After the treatment with the test item, the mean value of relative tissue viability was reduced to 93.8 %. This value is above the threshold for skin irritation potential (50 %). Test items that induce values above the threshold of 50 % are considered non-irritant to skin.

 

Therefore,2,2'-Azobis(2,4-dimethylvaleronitrile)is considered

non-irritant to skin in the Reconstructed human Epidermis (RhE) Test Method.