1,1'-azobis(1-cyclohexanecarbonitrile)

Skin irritation / corrosion

Administrative data

Endpoint:

skin irritation: in vitro / ex vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

24.06.-28.07.17

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 guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

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

Version / remarks:

28.07.15

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method B.46 (In Vitro Skin Irritation: Reconstructed Human Epidermis Model Test)

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

1,1'-azobis(1-cyclohexanecarbonitrile)

EC Number:

218-254-8

EC Name:

1,1'-azobis(1-cyclohexanecarbonitrile)

Cas Number:

2094-98-6

Molecular formula:

C14H20N4

IUPAC Name:

1,1'-azobis(1-cyclohexanecarbonitrile)

Test material form:

solid: granular

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:

The test system is a commercially available EpiDermTM-Kit, procured by MatTek.
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

EpiDermTM tissues were procured from MatTek-In Vitro Life Science Laboratories, Bratislava.
Designation of the kit: EPI-200-SIT
Day of delivery: 25. Jul. 2017
Batch no.: 25832

Control samples:

yes, concurrent negative control

yes, concurrent positive control

Amount/concentration applied:

TEST MATERIAL
- Amount(s) applied (volume or weight with unit): #1 24.7 mg, #2 25.0 mg, #3 25.1mg
- Concentration (if solution): -

VEHICLE
- Amount(s) applied (volume or weight with unit): -
- Concentration (if solution):-
- Lot/batch no. (if required):-
- Purity:-

NEGATIVE CONTROL
- Amount(s) applied (volume or weight): 30 µL DPBS buffer per tissue
- Concentration (if solution):

POSITIVE CONTROL
- Amount(s) applied (volume or weight): 30 µL SDS buffer per tissue
- Concentration (if solution):

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:

#1

Value:

111.2

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:

#2

Value:

110.9

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:

#3

Value:

105.2

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 was increased to 109.1 % after the treatment. This val-ue 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 as not skin irritant

Executive summary:

Three tissues of the human skin model EpiDerm^TMwere treated with1,1'-Azobis(cyclohexane-1-carbonitrile) 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 absorbance values were within the required acceptability criterion of 0.8 ≤ mean OD ≤ 2.8, OD was 1.6. The positive control showed clear irritating effects. The mean value of relative tissue viability was reduced to 3.0 % (required: ≤ 20 %).

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

 

After the treatment with the test item, the mean value of relative tissue viability was increased to 109.1 %. This value is above the threshold for skin irritation potential (50 %). Values above the threshold of 50 % are considered non-irritant to skin.

 

Therefore,1,1'-Azobis(cyclohexane-1-carbonitrile)is considered non-irritant to skin in the Reconstructed human Epidermis (RhE) Test Method.