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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:
August 14, 1989 - August 28, 1989
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: The study was performe according to OECD guideline and GLP.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1989
Report date:
1989

Materials and methods

Test guideline
Qualifier:
according to guideline
Guideline:
OECD Guideline 404 (Acute Dermal Irritation / Corrosion)
GLP compliance:
yes

Test material

Constituent 1
Chemical structure
Reference substance name:
Bisisobutyryl peroxide
EC Number:
222-340-0
EC Name:
Bisisobutyryl peroxide
Cas Number:
3437-84-1
Molecular formula:
C8H14O4
IUPAC Name:
2-methylpropanoyl 2-methylpropaneperoxoate
Details on test material:
Appearance:a clear, slightly viscous liquid
Batch No: 130789
Subsatnce ID: "Trigonox 187-C30, ex ch 130789""
Chemical name: Diisobutyrylperoxide.
Active ingredient and purity: diisobutyrylperoxide 30%
Trade name: Trigonox 187-C30,
cas Reg. no.: 3437-84-1

Test animals

Species:
rabbit
Strain:
New Zealand White
Details on test animals or test system and environmental conditions:
TEST ANIMALS
- Source: ENKI-Konijnenfarm, Someren, the Netherlands
- Age at study initiation: young adult
- Weight at study initiation: 2800 g
- Housing: The animal was housed in a suspended, galvanized cage, fitted with a wire-mesh floor and front
- Diet (e.g. ad libitum): standard laboratory rabbit diet, ad libitum
- Water (e.g. ad libitum): tap water, ad libitum
- Acclimation period: 6 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 20 ± 3
- Humidity (%): at least 40%
- Air changes (per hr): 10
- Photoperiod (hrs dark / hrs light): natural day/night cycle

IN-LIFE DATES: August 14, 1989 - August 28, 1989

Test system

Type of coverage:
semiocclusive
Preparation of test site:
shaved
Vehicle:
unchanged (no vehicle)
Controls:
no
Amount / concentration applied:
TEST MATERIAL
- Amount(s) applied (volume or weight with unit): 0.5 ml
Duration of treatment / exposure:
4 hours
Observation period:
Skin readings were made at approximately one hour, 24, 48 and 72 hours, and at 8 and 14 days after treatment.
Number of animals:
1, the effects were of a very severe degree. Therefore, it was decided not to continue the study with another two rabbits.
Details on study design:
TEST SITE
- Area of exposure: back
- % coverage: 2.5 x 2.5 em patch
- Type of wrap if used: The patch was immediately placed on the intact skin and fixed to the application site by means of adhesive tape (Leukopor, BDF). The entire trunk of the rabbit was wrapped with a self-adhesive-gauze (Fixomull, art. no. 2112, BDF, W.-Germany) to maintain the patch in position.

REMOVAL OF TEST SUBSTANCE
- Washing (if done): No details on removal.
- Time after start of exposure: After an exposure period of 4 hours the patch and the material applied were removed.

SCORING SYSTEM: Draize
A. Erythema and eschar formation
No erythema 0
Very slight erythema (barely perceptible) 1
Well-defined erythema 2
Moderate to severe erythema 3
Severe erythema (beet redness); eschar formation (injuries in depth: ischemia, haemorrhages, and incrustation) 4
B. oedema formation
No oedema 0
Very slight oedema (barely perceptible) 1
Slight oedema (edges of area well-defined by
definite raising) 2
Moderate oedema (raised approximately 1 millimeter) 3
Severe oedema (raised more than 1 millimeter, extending beyond the area of exposure) 4

Results and discussion

In vivo

Resultsopen allclose all
Irritation parameter:
erythema score
Basis:
animal #1
Time point:
24/48/72 h
Score:
4
Max. score:
4
Reversibility:
not fully reversible within: 14 days
Remarks on result:
other: scar tissue was observed after 14 days
Irritation parameter:
edema score
Basis:
animal #1
Time point:
24/48/72 h
Score:
4
Max. score:
4
Reversibility:
not fully reversible within: 14 days
Remarks on result:
other: scar tissue was observed after 14 days
Irritant / corrosive response data:
At 1, 24, 48, and 72 hours after removal, the skin effects observed consisted of severe ischemic necrosis and severe oedema.
At 8 days after treatment, severe incrustation was observed on the entire area of the application site.
At 14 days after treatment, the incrustation had loosened and scar tissue was now observed on the entire area of the application site.

Applicant's summary and conclusion

Interpretation of results:
Category 1 (corrosive) based on GHS criteria
Conclusions:
The results for 30% diisobutyryl peroxide in a phlegmatizer would result in a classification as corrosive to the skin.
Executive summary:

A 30% dilution of diisobutyIyl peroxide was examined for acute dermal irritating/corrosive properties in an experiment with one albino rabbit. The dermal exposure period was four hours. The test substance caused severe ischemic necrosis, severe incrustation, and severe oedema. At 14 days after treatment, scar tissue was observed on the entire area of the application site. Because of the severe degree of the skin effects, the study was conducted with only one animal instead of three. On the basis of the results obtained it was concluded that, under the conditions of this study, a 30% dilution of diisobutyryl peroxide is corrosive to skin.