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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
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:
1978
Report Date:
1978

Materials and methods

Test guideline
Qualifier:
equivalent or similar to
Guideline:
OECD Guideline 404 (Acute Dermal Irritation / Corrosion)
Deviations:
no
Principles of method if other than guideline:
Method: Draize Test
GLP compliance:
no

Test material

Reference
Name:
Unnamed
Type:
Constituent

Test animals

Species:
rabbit
Strain:
New Zealand White

Test system

Type of coverage:
occlusive
Preparation of test site:
abraded
Remarks:
and intact skin
Vehicle:
unchanged (no vehicle)
Controls:
not specified
Amount / concentration applied:
0.5 mL of the undiluted test substance
Duration of treatment / exposure:
24 hour(s)
Observation period:
7 days
Number of animals:
12 (6 animals were treated on intact skin)
Details on study design:
TEST PROCEDURE
- Primary irritation to the skin was measured by a patch-test technique on the abraded and intact skin of albino rabbits. Twelve healthy adult New Zealand White albino rabbits were used for the test substance.
- Pretreatment: 24 hours prior to applying the material, the hair was removed from the backs of the animals with an electric clipper in such a way as to avoid abrasions
- Application procedure: The test substance was brought on the intact or abraded skin under a surgical patch measuring 1 inch x 1 inch. The patches were fixed to the application site by means of adhesive tape and the entire trunk of the rabbits was wrapped with an impervious material to maintain the test patches in position and to retard evaporation of volatile substances.
- Abrasions: The abrasions are minor incisions through the stratum corneum, but not sufficiently deep to disturb the derma or to produce bleeding.
- Exposure: After an exposure period of 24 hours the patches and the material applied were removed.
- Readings of skin reactions: Readings were performed after 24 and 72 hours. If, at the second reading, distinct irritation was observed a third reading was performed after seven days. After the final reading all rabbits were killed and, in the case of eschar formation, the scab was removed to examine the nature of the underlying tissue damage.

Results and discussion

In vivo

Resultsopen allclose all
Irritation parameter:
primary dermal irritation index (PDII)
Basis:
mean
Time point:
other: 24 and 72 h
Score:
2.4
Max. score:
8
Remarks on result:
other:
Remarks:
intact skin
Irritation parameter:
erythema score
Basis:
mean
Time point:
other: 24 and 72 h
Score:
1.42
Max. score:
4
Reversibility:
not fully reversible within: 72 h
Remarks on result:
other:
Remarks:
intact skin
Irritation parameter:
edema score
Basis:
mean
Time point:
other: 24 and 72 h
Score:
0.6
Max. score:
4
Reversibility:
not fully reversible within: 72 h
Remarks on result:
other:
Remarks:
intact skin
Irritant / corrosive response data:
After 24 hours, intact skin : very slight or well-defined erythema and very slight edema .
After 24 hours, abraded skin: very slight or well-defined erythema, slight ischemia and slight edema.
After 72 hours, intact skin: very slight or well-defined erythema, slight scaliness and very slight edema.
After 72 hours, abraded skin: very slight erythema, slight scaliness and very slight edema.
On the abraded skin the test compound caused edema to a slightly higher degree than on the intact skin .
As to the other dermal effects observed there were no differences between reactions of the intact skin and those of the abraded skin .

Any other information on results incl. tables

Generally, the following dermal effects were observed:
After 24 hours, intact skin: very slight or well-defined erythema and very slight edema.
After 72 hours, intact skin: very slight or well-defined erythema, slight scaliness and very slight edema.
On the abraded skin the test compound caused edema to a slightly higher degree than on the intact skin.
As to the other dermal effects observed, there were no differences between reactions of the intact skin and those of the abraded skin.


I
ndividual and average skin irritation scores:

 

Intact skin

 

Abraded skin

No. Animal

24 h

72 h

No. animal

24 h

72 h

 

A

B

A

B

 

A

B

A

B

1

2

1

1

0

 

2

2

1

1

2

2

1

1

0

 

4

2

1

0

3

1

0

1

0

 

2

2

1

0

4

1

1

1

0

 

2

2

1

1

5

2

1

2

1

 

2

2

1

0

6

2

1

1

1

 

1

1

1

0

average

1.7

0.8

1.2

0.3

 

2.1

1.8

1.0

0.3

Sum

2.5

1.5

 

4.0

1.3


A: erythema
B: edema


Mean values over 24 and 72 hours (intact skin):

No. Rabbit

Erythema

Edema

1

1.5

0.5

2

1.5

0.5

3

1.0

0.0

4

1.0

0.5

5

2.0

1.0

6

1.5

1.0

 average  1.42  0.6

Applicant's summary and conclusion

Interpretation of results:
GHS criteria not met