2,2'-azobis[2,4-dimethylvaleronitrile]

Skin irritation / corrosion

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

Guideline:

OECD Guideline 439 (In Vitro Skin Irritation: Reconstructed Human Epidermis Test Method)

Version / remarks:

2015

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

2,2'-azobis[2,4-dimethylvaleronitrile]

EC Number:

224-583-8

EC Name:

2,2'-azobis[2,4-dimethylvaleronitrile]

Cas Number:

4419-11-8

Molecular formula:

C14H24N4

IUPAC Name:

2-[(E)-2-(1-cyano-1,3-dimethylbutyl)diazen-1-yl]-2,4-dimethylpentanenitrile

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

Results

Results 1

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

Results 2

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

Results 3

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 EpiDerm^TMwere 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.