2,2'-dimethyl-2,2'-azodipropiononitrile

Skin irritation / corrosion

Administrative data

Endpoint:

skin irritation: in vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

3 July 1996 - 6 July 1996

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1996

Report date:

1996

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 404 (Acute Dermal Irritation / Corrosion)

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

2,2'-dimethyl-2,2'-azodipropiononitrile

EC Number:

201-132-3

EC Name:

2,2'-dimethyl-2,2'-azodipropiononitrile

Cas Number:

78-67-1

Molecular formula:

C8H12N4

IUPAC Name:

2,2'-dimethyl-2,2'-azodipropiononitrile

Details on test material:

- Name of test material (as cited in study report): 2,2'-AZOBIS(ISOBUTYRONITRILE)
- molecular weight: 164.24
- Physical state: solid (white powder)
- Analytical purity: 99.2%
- Purity test date: 27.03.1995
- Lot/batch No.: 721
- Expiration date of the lot/batch: 04.1997
- Storage condition of test material: in dark at <15°C

Test animals

Species:

rabbit

Strain:

New Zealand White

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Elevage cunicole de Val de Selle, 80160 Prouzel, FRANCE.
- Weight at study initiation: 2.7 +/- 0.1 kg
- Housing: Individually in polystyrene cages (35 cm x 55 cm x 32 cm or 48.2 cm x 58 cm x 36.5 cm)
- Diet (e.g. ad libitum): ad libitum
- Water (e.g. ad libitum): ad libitum
- Acclimation period: At least five days before the beginning of the study

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 18 +/- 3 °C
- Humidity (%): 30 to 70 %
- Air changes (per hr): 12
- Photoperiod (hrs dark / hrs light): 12h / 12h

Test system

Type of coverage:

semiocclusive

Preparation of test site:

other: clipped

Vehicle:

unchanged (no vehicle)

Controls:

other: the untreated skin served as control

Amount / concentration applied:

TEST MATERIAL
- Amount(s) applied (volume or weight with unit): 500 mg

Duration of treatment / exposure:

4 hours

Observation period:

The skin was examined 1 hour, 24, 48 and 72 hours after removal of the dressing. If there were persistent cutaneous reactions after 72 hours, the observation was extended to a maximum of 14 days (until day 15) in order to determine the progress of the lesions and their reversibility.

Number of animals:

3 rabbits

Details on study design:

TEST SITE
- Area of exposure: 6 cm2
- Type of wrap if used: semi-occlusive


REMOVAL OF TEST SUBSTANCE
Any residual was wiped off by means of a dry gauze pad.

SCORING SYSTEM:
Dermal irritation was evaluated for each animal according to the grading scale as per OECD test guideline 404 (see below).

Results and discussion

In vivo

Results

Results 1

Irritation parameter:

erythema score

Basis:

animal #1

Time point:

24 h

Score:

0

Max. score:

4

Results 2

Irritation parameter:

erythema score

Basis:

animal #2

Time point:

48 h

Score:

0

Max. score:

4

Results 3

Irritation parameter:

erythema score

Basis:

animal #3

Time point:

72 h

Score:

0

Max. score:

4

Results 4

Irritation parameter:

edema score

Basis:

animal #1

Time point:

24 h

Score:

0

Max. score:

4

Results 5

Irritation parameter:

edema score

Basis:

animal #2

Time point:

48 h

Score:

0

Max. score:

4

Results 6

Irritation parameter:

edema score

Basis:

animal #3

Time point:

72 h

Score:

0

Max. score:

4

Irritant / corrosive response data:

No cutaneous reactions were observed during the study.

Applicant's summary and conclusion

Interpretation of results:

not irritating

Remarks:

According to EU regulation (EC) No 1272/2008 (CLP)

Conclusions:

No cutaneous reactions were observed after a 4-hour exposure period onto the skin of 3 rabbits. According to the criteria laid down in Council Directive 67/548/EEC (and subsequent adaptations) on the approximation of laws, regulations and administrative provisions relative to the classification, packaging and labelling of dangerous substances, the test item is considered as non-irritant to the skin.

Executive summary:

The potential of the test item 2,2'-AZOBIS(ISOBUTYRONITRILE) to induce skin irritation was evaluated in rabbits according to OECD guideline 404. The study was conducted in compliance with the principles of the Good Laboratory Practice Regulations.

Methods:

The test item was applied for 4 hours to 3 New Zealand White rabbits. A single dose of 500 mg of the test substance was applied to the closely-clipped skin of the flank. The test substance was held in contact with the skin by means of a semi-occlusive dressing. Cutaneous reactions were observed approximately 1 hour, 24, 48 and 72 hours after removal of the dressing. The mean values of the scores for erythema and oedema were calculated for each animal.

Results:

No cutaneous reactions were observed during the study.

Conclusion:

 The test item 2,2' AZOBIS(ISOBUTYRONITRILE) is considered as non-irritant to the skin and is not classified.