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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:
6-22 March 1979
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
comparable to guideline study with acceptable restrictions

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1979
Report Date:
1979

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
other: FDA guideline 1500.41 in Federal Register 38, no. 187, 27-09-1973, p 27019
Principles of method if other than guideline:
Examination of skin irritation in rabbits, see further below
GLP compliance:
no
Remarks:
did not exist at that time

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
not available
Specific details on test material used for the study:
crystalline flakes dissolved in physiological saline

Test animals

Species:
rabbit
Strain:
Himalayan
Details on test animals and environmental conditions:
Strain: Hoe:HIMK (SPFWiga) - own breed
Body weight: 1.5-2.5 kg
Standard feed: ERKA 8300
Food and water ad libitum

Test system

Type of coverage:
occlusive
Preparation of test site:
other: intact shaved and abraded skin
Vehicle:
physiological saline
Controls:
no
Amount / concentration applied:
first test: 500 mg pasted with 0.05 ml vehicle
second test: 100 mg/kg as 50% solution in vehicle
Duration of treatment / exposure:
24 h
Observation period:
24, 48 and 72 h
Number of animals:
6 per group
Details on study design:
2.5 cm2 application area

Results and discussion

In vivo

Results
Irritation parameter:
other: Irritation index
Basis:
mean
Time point:
other: 24 and 72 h
Score:
4.8
Max. score:
8
Reversibility:
not reversible
Remarks on result:
probability of severe irritation
Remarks:
In this older study other scoring criteria have been used
Irritant / corrosive response data:
first test: all animals died within 24 h; skin was hard and black-green discoloured. A section of the skin showed a clear 'liver lobe drawing'. The subcutaneous tissue in the area of ​​the treatment sites was without abnormalities.

second test:
- at 24 h: very strong erythema and edema. The skin was grey-green discoloured, at the edges it was cracked and a colourless fluid was secreted.
- at 48 h: clear reduction of erythema and edema; detachment of discoloured and corroded skin started
- at 72 h: the skin of all animals was indurated, bulged, parchment-like, deeply cracked and showed large-area skin detachment. In 5 rabbits open wounds with colourless (3) or reddish coloured (2) secretion were observed.
Other effects:
not reported

Any other information on results incl. tables

For both erythema and oedema a maximum score of 4 was used.

The final score (Irritation index) for every animal was obtained by adding the score of erythema and edema for both intact and abraded skin at 24 and 72 h. The sum of all animals was taken and divded by the number of animals and a factor 4.

The classification was as follows:

0.0 -0.5 = non irritant

0.6 -3.0 = slightly irritating

3.1 -5.0 = moderately irritating

5.1 -8.0 = severely irritating

In this study the irritation index was 4.8, and thus moderately irritating. However, there was an etching effect and as such MCA should be considered as strongly irritating/corrosive.

Applicant's summary and conclusion

Interpretation of results:
Category 1 (corrosive) based on GHS criteria
Conclusions:
In this study the irritation index was 4.8 (maximum is 8), and thus moderately irritating. However, there was an etching effect and as such MCA should be considered as strongly irritating/corrosive.