2,2'-azobis[2-methylbutyronitrile]

Endpoint summary

Description of key information

The test substance did not produce skin or eye irritation/corrosion in OECD guideline, GLP studies.

Key value for chemical safety assessment

Skin irritation / corrosion

Link to relevant study records

Reference

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.

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

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.

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

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

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

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

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

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

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

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.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not irritating)

Eye irritation

Link to relevant study records

Reference

Endpoint:

eye 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.

Qualifier:

according to guideline

Guideline:

OECD Guideline 405 (Acute Eye Irritation / Corrosion)

Deviations:

no

Remarks:

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

GLP compliance:

yes

Species:

rabbit

Strain:

New Zealand White

Details on test animals or tissues and environmental conditions:

TEST ANIMALS
- Age at study initiation: approximately three and a half to four months old
- Weight at study initiation: 2.76 - 3.30 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: three or four weeks

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 39 - 56% 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.

Vehicle:

unchanged (no vehicle)

Controls:

other: The untreated eye was used as a comparison with the treated eye during assessment of ocular lesions.

Amount / concentration applied:

TEST MATERIAL
- Amount(s): 0.1 g

Duration of treatment / exposure:

72 hours

Observation period (in vivo):

Ocular reactions to treatment were assessed one hour, 24, 48 and 72 hours after treatment

Number of animals or in vitro replicates:

3

Details on study design:

REMOVAL OF TEST SUBSTANCE
- Washing: no

SCORING SYSTEM: Draize, JH (1959). In "Appraisal of the Safety of Chemicals in Foods, Drugs and Cosmetics" p.47. Association of Food and
Drug Officials of the United States, Austin, Texas.

The Official Journal of the European Communities (L257/8-9, Vol. 26., 16/9/83 and L257/19, Vol.26., 16/9/83) Directive 83/467/EEC.

TOOL USED TO ASSESS SCORE: An ophthalmoscope was used to facilitate inspection of the eyes.

Irritation parameter:

chemosis score

Basis:

mean

Time point:

24/48/72 h

Score:

0

Max. score:

4

Remarks on result:

other: Slight irritation in all three animals and iritis score 1 in two animals observed one hour after installation. Complete reversibility with 24 hours

Irritation parameter:

conjunctivae score

Basis:

mean

Time point:

24/48/72 h

Score:

0

Max. score:

3

Remarks on result:

other: Slight irritation in all three animals and iritis score 1 in two animals observed one hour after installation. Complete reversibility with 24 hours

Irritation parameter:

cornea opacity score

Basis:

mean

Time point:

24/48/72 h

Score:

0

Max. score:

4

Remarks on result:

other: no corneal opacity observed in any animal

Irritation parameter:

iris score

Basis:

mean

Time point:

24/48/72 h

Score:

0

Max. score:

2

Remarks on result:

other: Slight irritation in all three animals and iritis score 1 in two animals observed one hour after installation. Complete reversibility with 24 hours

Irritant / corrosive response data:

A diffuse crimson-red appearance to the conjunctiva and slight chemosis and/or discharge were observed in all animals one hour after
instillation. Iritis was also observed in two rabbits at this time. The eyes of all rabbits were overtly normal at the 24 hour observation.
Instillation of the test material caused a very slight initial pain response.

The mean values for ocular lesions recorded 24, 48 and 72 hours after treatment did not equal or exceed the EEC limit values for classifying the test material as irritant to the eye.

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 eye.

Executive summary:

The test substance was evaluated for acute eye irritation potential in 3 young adult New Zealand white rabbits. An aliquot of 0.1 g of the test substance was administered to 1 eye of each animal. The eyes remained unwashed following treatment. The untreated eye served as a control. The conjunctiva, iris, and cornea of each treated eye were evaluated and scored according to a numerical scale approximately 1, 24, 48, and 72 hours, following administration. A diffuse crimson-red appearance to the conjunctiva and slight chemosis and/or discharge were observed in all animals one hour after instillation. Iritis was also observed in two rabbits at this time. The eyes of all rabbits were overtly normal at the 24 hour observation. All ocular irritation reversed by 24 hours.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not irritating)

Respiratory irritation

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information

The test substance did not produce skin or eye irritation/corrosion in OECD guideline, GLP studies.

Justification for classification or non-classification

The test substance did not produce skin or eye irritation/corrosion in OECD guideline, GLP studies. The substance does not need to be classified for irritation according EU Classification, Labelling and Packaging of Substances and Mixtures (CLP) Regulation (EC) No. 1272/2008.