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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:
1973
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:
1973

Materials and methods

Test guideline
Qualifier:
equivalent or similar to
Guideline:
OECD Guideline 404 (Acute Dermal Irritation / Corrosion)
Deviations:
yes
Remarks:
irritation parameters not recorded at 48 hours; test performed on both intact and abraded skin
GLP compliance:
no

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
liquid

Test animals

Species:
rabbit
Strain:
New Zealand White

Test system

Type of coverage:
not specified
Preparation of test site:
other: two test sites: one was abraded and the other intact
Vehicle:
unchanged (no vehicle)
Controls:
not specified
Duration of treatment / exposure:
24 and 72 hours
Observation period:
72 hours
Number of animals:
6 rabbits

Results and discussion

In vivo

Resultsopen allclose all
Irritation parameter:
erythema score
Basis:
mean
Time point:
24/48/72 h
Score:
ca. 4
Max. score:
4
Reversibility:
fully reversible
Remarks on result:
other: Intact skin, average of 6 rabbits
Irritation parameter:
erythema score
Basis:
mean
Time point:
24/48/72 h
Score:
ca. 4
Max. score:
4
Reversibility:
fully reversible
Remarks on result:
other: Abraded skin - Average of 6 rabbits
Irritation parameter:
edema score
Basis:
mean
Time point:
24/48/72 h
Score:
ca. 2.9
Max. score:
4
Reversibility:
fully reversible
Remarks on result:
other: Intact skin - Average from 6 rabbits
Irritation parameter:
edema score
Basis:
mean
Time point:
24/48/72 h
Score:
ca. 2.8
Max. score:
4
Reversibility:
fully reversible
Remarks on result:
other: Abraded skin - Average of 6 rabbits
Irritant / corrosive response data:
Mean (24, 48, 72 hour) scores, with 48 hour score estimated based on the worse of either 24 or 72 hour scores, using a worst case scenario approach):
ERYTHEMA:
- Animals 1-6 (all): 4 (at all time points on all animals, on both intact and abraded skin)
OEDEMA:
- Animals 1, 2, 5, 6: 3 at 24 hours; 2 at 72 hours (both intact and abraded skin)
- Animals 3, 4: 4 at 24 hours; 2 at 72 hours (both intact and abraded skin)

Any other information on results incl. tables

Table: Results for erythema and oedema.

Erythema formation 1 2 3 4 5 6
Intact skin 24 h 4 4 4 4 4 4
72 h  4 4 4 4 4 4
Abraded skin 24 h 4 4 4 4 4 4
72 h  4 4 4 4 4 4
Oedema formation 1 2 3 4 5 6
Intact skin 24 h 3 3 4 4 3 3
72 h  2 2 2 2 2 2
Abraded skin 24 h 3 3 4 4 3 3
72 h  2 2 2 2 2 2

Applicant's summary and conclusion

Interpretation of results:
other: Category 2 (Skin irritant) based on CLP Regulation (EC) no. 1272/2008
Conclusions:
Severely irritating to rabbit skin
Erythema score: 4.0 (6 animals, at both 24 & 72 h, intact skin)
Oedema score: 3.33 at 24 hours (mean, 6 animals, intact skin) and 2.0 (6 animals, 72 h, intact skin)
Executive summary:

The skin irritation potential of the substance was evaluated in an in vivo experimental study similar to the OECD Guideline 404. The test item was applied as is to both an intact site and an abraded site of six New Zealand white rabbits, and the sites were monitored for erythema and oedema according to the Draize scale, at 24 and 72 hours after application.

All six animals demonstrated an erythema score of 4.0 at both the 24 hour and the 72 hour monitoring of both the intact and the abraded skin sites. Four out of the six animals demonstrated an oedema score of 3.0 at 24 hours on both the intact and abraded sites; the remaining two animals had a score of 4.0 at the same sites and times. At 72 hours, all six animals demonstrated an oedema score of 2.0 at both the intact and abraded sites. Reversibility of erythema and oedema was not monitored beyond 72 hours in this study. Based on these findings, the substance is considered irritating to rabbit skin.

For evaluation using the CLP regulation, it is necessary to calculate the mean erythema and oedema scores at 24, 48 and 72 hours for each animal at the intact site only. As no data for the 48 hour interval was recorded in this study, the mean was calculated using a worst-case approach, whereby the more severe of the 24 or 72 hour scores in place of the 48 hour score. The mean (24/48/72 h) erythema scores were 4.0 for all 6 animals; the mean (24/48/72 h) oedema scores were 2.67 for 4 animals, and 3.33 for 2 animals.