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Toxicological information

Skin irritation / corrosion

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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:
other: GLP 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:
OECD Guideline 404 (Acute Dermal Irritation / Corrosion)
GLP compliance:
yes

Test material

Reference
Name:
Unnamed
Type:
Constituent
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 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

Resultsopen allclose all
Irritation parameter:
erythema score
Basis:
mean
Remarks:
3 rabbits
Time point:
other: 24, 48 and 72 hours
Score:
0
Max. score:
4
Irritation parameter:
edema score
Basis:
mean
Remarks:
3 rabbits
Time point:
other: 24, 48 and 72 hours
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:
Migrated information Criteria used for interpretation of results: other: According to EU regulation (EC) No 1272/2008 (CLP) and EU Directive 67/584/EEC
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:

According to the criteria laid down in Council Directive 67/548/EEC (and subsequent adaptations), the test item 2,2' AZOBIS(ISOBUTYRONITRILE) is considered as non-irritant to the skin and is not classified.