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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, 1977
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Well-conducted study done according to guideline in force at the time. Documentation is sufficient but not extensive, also as was practice when the study was done. Study was performed prior to GLP regulations.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1978
Report Date:
1978

Materials and methods

Test guidelineopen allclose all
Qualifier:
equivalent or similar to
Guideline:
OECD Guideline 404 (Acute Dermal Irritation / Corrosion)
Deviations:
yes
Remarks:
Application time was 24 hours instead of four.
Qualifier:
according to
Guideline:
EPA OPPTS 870.2500 (Acute Dermal Irritation)
Deviations:
no
Remarks:
Application time was 24 hours which is permitted in this guideline.
GLP compliance:
no
Remarks:
Study was performed prior to GLP regulations.

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
other: clear, colourless liquid
Details on test material:
None

Test animals

Species:
rabbit
Strain:
New Zealand White

Test system

Type of coverage:
occlusive
Preparation of test site:
other: Six rabbits treated on intact skin, six on abraded skin.
Vehicle:
unchanged (no vehicle)
Controls:
not required
Amount / concentration applied:
0.5 ml
Duration of treatment / exposure:
24 hours
Observation period:
72 hours after application
Number of animals:
Twelve (six intact skin, six abraded skin)
Details on study design:
Primary irritation to the skin is measured by a patch-test technique on the abraded and intact skin of albino rabbits.

Twelve healthy adult New Zealand White albino rabbits are used for 1-4 test substances. Twenty four hours prior to applying the materials, the hair is removed from the backs of the animals with an electric clipper in such a way as to avoid abrasions.

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 84 (1944) 377-390). A second reading is made 48 hours later (72 hours after application).

Results and discussion

In vivo

Results
Irritation parameter:
overall irritation score
Basis:
mean
Time point:
other: 24 hours
Score:
6.8
Max. score:
7
Reversibility:
not fully reversible within: 72 hours
Remarks on result:
other: see table below
Remarks:
see table below
Irritant / corrosive response data:
The individual and average skin irritation scores are presented in the table below. Generally, the dermal effect of TMPH after 24 hours was distinct ischemia and slight or moderate edema.
Other effects:
None recorded.

Any other information on results incl. tables

sa

 Rabbit number

Intact skin

24 hours

Intact skin

72 hours

Rabbit number

Abraded skin

24 hours

Abraded skin

72 hours

  erythema - edema   erythema - edema
 6609  4 - 2  4  6603  4 - 3  4
 6610  4 - 3  4 6604   4 - 3  3
 6611  4 - 3  4 6605   4 - 3  4
 6612  4 - 3  4 6606   4 - 3  4
 6613  4 - 3  4  6607  4 - 3  4
 6614  4 - 3  4  6608  4 - 2  4
 average  6.8  4.0    6.8  3.8

Applicant's summary and conclusion

Interpretation of results:
Category 1B (corrosive) based on GHS criteria
Remarks:
Migrated information Criteria used for interpretation of results: other: Draize
Conclusions:
The following degree of skin irritation was observed. TMPH: very severe.
Executive summary:

Primary irritation to the skin is measured by a patch-test technique on the abraded and intact skin of albino rabbits.

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 84 (1944) 377-390). A second reading is made 48 hours later (72 hours after application).

The following degree of skin irritation was observed. TMPH: very severe. Generally, the dermal effect of TMPH after 24 hours was distinct ischemia and slight or moderate edema.