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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:
June 1981
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
study well documented, meets generally accepted scientific principles, acceptable for assessment

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1981
Report date:
1981

Materials and methods

Test guideline
Qualifier:
equivalent or similar to guideline
Guideline:
OECD Guideline 404 (Acute Dermal Irritation / Corrosion)
GLP compliance:
no

Test material

Reference
Name:
Unnamed
Type:
Constituent
Type:
additive
Test material form:
other: clear colorless liquid
Details on test material:
A sample of the test matetial designated:
t-amyl peroxypivalaate was received from the
principal on June. 3, 1981.
The test material, a clear colourless liquid
was stored at -20°C until use.

Test animals

Species:
rabbit
Strain:
New Zealand White
Details on test animals or test system and environmental conditions:
None provided

Test system

Type of coverage:
occlusive
Preparation of test site:
other: intact and abraded
Vehicle:
unchanged (no vehicle)
Controls:
no
Amount / concentration applied:
0.5 ml
Duration of treatment / exposure:
24 hours
Observation period:
72 hours
Number of animals:
six
Details on study design:
Primary irritation to the skin is measured by patch test technique on the abraded and intact skin of albino rabbits. Twelve healthy adult New Zealand White albino rabbits were used. Twenty four hours prior to applying the material the hair is removed from the backs of the animals with an electric clipper in such away as to avoid abrasion.
An amount of 0.5 ml (in case of liquids) or 0.5 g (in case of solids or semi-solids) of the test substance is brought on the intact or abraded skin under a surgical patch measuring 1 inch x 1 inch; The patches are fixed to the application site by means of adhesive tape and the entire trunk of the rabbits is wrapped with an impervious material to maintain the test patches in position and to retard evaporation of volatile substances.

Six rabbits are treated on the intact skin, the other six on the abraded skin. The abrasions are minor incisions through the stratum corneum but not sufficiently deep to disturb the derma or to produce bleeding.

After an exposure period of 24 hours the patches and the material applied are removed and the resulting skin reactions are evaluated by the method of Draize (J. Pharmacol. 82 (1944) 377 - 390). A second reading is made 48 hours later (72 hour after application).

Results and discussion

In vivo

Resultsopen allclose all
Irritation parameter:
edema score
Basis:
animal: all animals
Time point:
24/48/72 h
Remarks on result:
not measured/tested
Irritation parameter:
erythema score
Basis:
animal: all animals
Time point:
24/48/72 h
Remarks on result:
not measured/tested
Irritation parameter:
erythema score
Basis:
mean
Time point:
24 h
Score:
4
Max. score:
4
Reversibility:
not fully reversible within: 72 hours
Remarks:
No further observations were made
Remarks on result:
positive indication of irritation
Irritation parameter:
erythema score
Basis:
mean
Time point:
72 h
Score:
3.33
Max. score:
4
Reversibility:
not fully reversible within: 72 hours
Remarks:
No further observations were made
Remarks on result:
positive indication of irritation
Irritation parameter:
edema score
Basis:
mean
Time point:
24 h
Score:
2
Max. score:
4
Reversibility:
not fully reversible within: 72 hours
Remarks:
No further observatiosn were made
Remarks on result:
positive indication of irritation
Irritation parameter:
edema score
Basis:
mean
Time point:
72 h
Score:
0.5
Max. score:
4
Reversibility:
not fully reversible within: 72 hours
Remarks:
No further observations were made
Remarks on result:
positive indication of irritation
Irritant / corrosive response data:
The test product caused severe skin irritation.
The dermal effects after 24 hours generally consisted of ischemia and slight or moderate edema.
After 72 hours distinct scaliness was noted at two intact sites, while the other sites by then showed ischemia, slight or distinct incrustation and/or very slight edema.
In general, the reactions of the abraded skin were slightly more pronounced than those of the intact skin.

Any other information on results incl. tables

CLP criteria:

1) Mean value of ≥ 2,3 - ≤ 4,0 for erythema/ eschar or for oedema in at least 2 of 3 tested animals from gradings at 24, 48 and 72 hours after patch removal or, if reactions are delayed, from grades on 3 consecutive days after the onset of skin reactions; or

(2) Inflammation that persists to the end of the observation period normally 14 days in at least 2 animals, particularly taking into account alopecia (limited area), hyperkeratosis, hyperplasia, and scaling; or

(3) In some cases where there is pronounced variability of response among animals, with very definite positive effects related to chemical exposure in a single animal but less than the criteria above.

 

The summary below is based on the observation made in the animals with intact skin after 24 hours of occlusive exposure:

 

Erythema

Animal/score at:

24h

72h

mean

7

4

2

3

8

4

4

4

9

4

4

4

10

4

2

3

11

4

4

4

12

4

4

4

 

Oedema

Animal/score at:

24h

72h

mean

7

1

0

0.5

8

2

0

1

9

3

1

2

10

2

1

1.5

11

2

1

1.5

12

2

0

1

Applicant's summary and conclusion

Interpretation of results:
Category 2 (irritant) based on GHS criteria
Conclusions:
On the basis of the present results it is concluded that tert-amyl peroxypivalate is a severe primary skin irritant and is classified in category.
Executive summary:

The test article was evaluated for potential skin irritation following application to the intact and abraded skin of rabbits. The test sites were evaluated 24 hours following application and again 48 hours later according to the Draize method.

The test product caused severe skin irritation.

The dermal effects after 24 hours generally  consisted of ischemia and slight or moderate edema.

After 72 hours distinct scaliness was noted at two intact sites, while the other sites by then showed ischemia, slight or distinct incrustation and/or very slight edema.

In general, the reactions of the abraded skin were slightly more pronounced than those of the intact skin.