Registration Dossier

Toxicological information

Skin irritation / corrosion

Currently viewing:

Administrative data

Endpoint:
skin irritation: in vivo
Type of information:
experimental study
Adequacy of study:
key study
Study period:
15th-18th February 1983
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: Proprietary guideline-compliant study
Cross-reference
Reason / purpose:
reference to other study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1983

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
other: US Department of Transport
Deviations:
no
Principles of method if other than guideline:
Corrosivity screening test in the rabbit in vivo
GLP compliance:
no
Remarks:
Pre-GLP study

Test material

Reference
Name:
Unnamed
Type:
Constituent
Type:
Constituent
Details on test material:
Red powder: no further details provided. The test material was a mixture of chromium (VI) trioxide from different sources.

Test animals

Species:
rabbit
Strain:
New Zealand White

Test system

Type of coverage:
occlusive
Preparation of test site:
shaved
Vehicle:
physiological saline
Controls:
not required
Amount / concentration applied:
0.5 g, moistened with 0.5 ml saline
Duration of treatment / exposure:
Up to 30 minutes
Observation period:
Up to 1 hour
Number of animals:
Two
Details on study design:
Two animals were exposed for three minutes and observed at regular intervals for corrosive effects.

Results and discussion

In vivo

Results
Irritation parameter:
other: corrosivity
Basis:
mean
Reversibility:
not reversible
Irritant / corrosive response data:
Signs in both animals indicate local tissue destruction, which was confirmed by histopathology.
Other effects:
Histopathology showed coagulative necrosis of the epidermis and the outer dermis, with epidermal sloughing and capillary congestion.

Any other information on results incl. tables

Brown discoloration of the application site in the first animal after 3 minutes prevented the assessment of erythema; slight oedema (Grade 2) was apparent at this stage. Similar findings were noted at 15 minutes (following replacement of the patch). At 30 minutes Stage 3 oedema was observed and the animal showed signs of pain. The skin was noted to be hard and leathery. The animal was sacrificed at this point. The second animal showed signs of pain within 30 seconds of administration. Scoring of erythema was not possible after 3 minutes due to brown discoloration of the skin: the patch was not replaced at this point. Slight (Grade 2) oedema was apparent and the skin was hard. Moderate (Grade 3) oedema was seen at 30 and 60 minutes, at which point the animal was sacrificed.

Applicant's summary and conclusion

Interpretation of results:
corrosive
Remarks:
Migrated information Criteria used for interpretation of results: EU
Conclusions:
The results of the study show that chromium (VI) trioxide is corrosive to skin.
Executive summary:

0.5 g chromic acid (moistened with 0.5 ml physiological saline) was applied under occlusive conditions to the shorn dorsal skin of two rabbits. The application time in the first animal was 30 minutes; observations were made at up to 30 minutes, when the animal was sacrificed for humane reasons. Application time in the second animal was 3 minutes; observations were made for up to 1 hour, when the animal was sacrificed for humane reasons. In both animals, the skin at the application site appeared hard and brown, preventing the assessment of erythema. Oedema and pain were observed in both animals from early timepoints. Histopathology of skin at the application site confirmed a corrosive effect.