2,2'-azobis[2-methylbutyronitrile]

Skin irritation / corrosion

Administrative data

Endpoint:

skin irritation: in vivo

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: This study was selected as the key study because the information provided for the hazard endpoint is sufficient for the purpose of classification and labeling and/or risk assessment.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1991

Report date:

1991

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 404 (Acute Dermal Irritation / Corrosion)

Deviations:

no

Remarks:

The study was conducted according to the guideline in effect at the time of study conduct.

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

2,2'-azobis[2-methylbutyronitrile]

EC Number:

236-740-8

EC Name:

2,2'-azobis[2-methylbutyronitrile]

Cas Number:

13472-08-7

Molecular formula:

C10H16N4

IUPAC Name:

2,2'-diazene-1,2-diylbis(2-methylbutanenitrile)

Test material form:

solid: granular

Details on test material:

2,2'-Azo-bis (2-methyl-butyronitrile)
Product name: Perkadox AMBN
Batch: 32004091
CoA: March/May 1991
- Purity: 98.5%

Test animals

Species:

rabbit

Strain:

New Zealand White

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Age at study initiation: approximately three to four months old
- Weight at study initiation: 2.50 - 2.95 kg.
- Housing: They were individually housed in suspended stainless steel cages mounted in mobile batteries. The cages measured 61 x 76 x 46 cm high and were fitted with perforated counter-sunk floor panels. A tray beneath the floor was lined with absorbent crepe paper which was changed regularly.
- Diet: Animals had free access to a commercially available standard pelleted rabbit diet.
- Water: The rabbits had free access to tap water supplied to each cage by an automatic piped system.
- Acclimation period: at least seven days

ENVIRONMENTAL CONDITIONS
- The animals were housed in a lagomorph room within a limited-access building. The room was kept at slight positive pressure relative to the outside and had its own filtered air supply giving approximately 15 complete air changes per hour without re-circulation. A temperature range of 18-19°C and a relative humidity range of 46-62%. were achieved during the study. The achieved values were monitored daily. Electric time-switches operated a lighting cycle of 12 hours of artificial light per day. An emergency generator was available to maintain the electricity supply in the event of a power failure.

Test system

Type of coverage:

semiocclusive

Preparation of test site:

clipped

Vehicle:

unchanged (no vehicle)

Controls:

other: The right test site, acting as a control, was covered by a similar semi-occlusive dressing but otherwise remained untreated.

Amount / concentration applied:

TEST MATERIAL
Amount(s) applied: 0.5 g

Duration of treatment / exposure:

4 hours

Observation period:

one hour, 24, 48 and 72 hours after removal of the dressings

Number of animals:

3 males

Details on study design:

TEST SITE
- Two test sites (6 x 6 cm) were marked on either side of the clipped area of dorsum, and moistened by direct application of approximately 0.2 mL distilled water per test site. A single dose (0.5 g) was applied directly to the skin and covered by an unmedicated gauze patch (3 x 2 cm) which was held in place on the left test site by strips of Blenderm. The right test site, acting as a control, was covered by a similar semi-occlusive dressing but otherwise remained untreated. Pads of cotton 'wool' and elasticated bandage were used to protect the patches and ensure good contact between the skin and the test material during the four-hour exposure period. The elasticated bandage was held in place by thin strips of waterproof plaster at both edges.

REMOVAL OF TEST SUBSTANCE
- The dressings were removed after four hours exposure. Where necessary, the treatment sites were gently washed with warm water and dried with paper towels to remove excess test material adhering to the skin.

SCORING SYSTEM:
- according to the criteria of Draize

Results and discussion

In vivo

Results

Results 1

Irritation parameter:

erythema score

Basis:

animal #1

Time point:

24/48/72 h

Score:

0

Max. score:

4

Remarks on result:

no indication of irritation

Results 2

Irritation parameter:

erythema score

Basis:

animal #2

Time point:

24/48/72 h

Score:

0

Max. score:

4

Remarks on result:

no indication of irritation

Results 3

Irritation parameter:

erythema score

Basis:

animal #3

Time point:

24/48/72 h

Score:

0

Max. score:

4

Remarks on result:

no indication of irritation

Results 4

Irritation parameter:

edema score

Basis:

animal #1

Time point:

24/48/72 h

Score:

0

Max. score:

4

Remarks on result:

no indication of irritation

Results 5

Irritation parameter:

edema score

Basis:

animal #2

Time point:

24/48/72 h

Score:

0

Max. score:

4

Remarks on result:

no indication of irritation

Results 6

Irritation parameter:

edema score

Basis:

animal #3

Time point:

24/48/72 h

Max. score:

4

Remarks on result:

no indication of irritation

Irritant / corrosive response data:

No dermal response was observed at the test site of any animal at any time during the 72 hour observation period.

Other effects:

None

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Remarks:

Criteria used for interpretation of results: EU

Conclusions:

This study and the conclusions which are drawn from it fulfill the quality criteria (validity, reliability, repeatability).
Under the conditions of this test, the test item was classified as 'non-irritant' to the skin.

Executive summary:

The potential of the test substance to cause inflammatory or corrosive changes upon first contact with skin was assessed by semi-occluded application of 0.5 g of the test material to the closely-clipped dorsa of three New Zealand White rabbits for four hours. Dermal reactions were assessed 1, 24, 48 and 72 hours after removal of the dressings. No dermal response was observed at the test site of any animal at any time during the 72 hour observation period. Under the conditions of this test, the test substance was classified as 'non-irritant' to the skin.