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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:
weight of evidence
Study period:
1976
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:
1976
Report Date:
1976

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
other: “Hazardous Substances Regulations" under the U.S. Federal Hazardous Substances Labelling Act Sect. 191.11 (February 1965)
Version / remarks:
1965
GLP compliance:
no

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
solid: particulate/powder
Details on test material:
Vat Blue 20

Test animals

Species:
rabbit
Strain:
New Zealand White
Details on test animals and environmental conditions:
TEST ANIMALS
Healthy New Zealand White rabbits (Porton- strain) aged 11-12 weeks with average body weights of 2.57 kg (males) and 2.19 Kgs. (femals), bred on the premises and maintained under a semi-barrier system. Six rabbits (3 males and 3 females) were acclimatized in the test area for one week prior to the start of the study.

ENVIRONMENTAL CONDITIONS
The rabbits were caged singly in. an experimental room maintained at a temperature of 20°C (± 1) and a relative humidity of 50-70%. Animals were exposed to artificial light for 10 hours daily from 08.00 18.00 hours. A commercial irradiated diet (Styles-Oxoid) was fed ad libitum. Sterile filtered water was available at all times.

Test system

Type of coverage:
occlusive
Preparation of test site:
other: shaved and slightly scarified
Vehicle:
unchanged (no vehicle)
Controls:
yes, concurrent no treatment
Amount / concentration applied:
0.5 g
Duration of treatment / exposure:
24 hours
Observation period:
14 days
Number of animals:
3 males and 3 females
Details on study design:
The test was carried out according to the method given in the “Hazardous Substances Regulations" under the U.S. Federal Hazardous Substances Labelling Act Sect. 191.11 (February 1965).
Twenty-tour hours prior to the dermal application, the backs of the rabbits were shaved over an area consisting of at least 10% of the total body surface. Two test sites lateral to the mid line of the back were used an each rabbit. Immediately before the application of the test compound, the right hand site was abraded with the point of a sterile hypodermic needle. The abrasions were sufficiently deep to penetrate the stratum corneum but not to damage the dermis. The left hand site remained intact.
10 g of the test compound was mixed with 10 ml of water to make a suspension of 20 ml, 1.0 ml of which was applied each test site on a 2.5 cm square gauze pad. These were covered with aluminium foil secured with "Sleek" adhesive tape. The test sites were then covered by a 6" wide "Coban” self adhesive bandage in order to retain the test substance in dose contact with the skin.
After 24 hours the dressing was removed and the intact and abraded application sites were assessed for oedema and erythema. A further assessment was made at 72 hours and for any further period considered necessary up to 14 days.
The assessment of the macroscopic skin reaction was made according to the following grading system:

Score for skin irritation in rabbits (evaluation scheme)
Erythema and eschar formation
- No erythema: 0
- Very slight erythema (barely perceptible): 1
- Well defined erythema: 2
- Moderate to severe erythema: 3
- Severe erythema (beet redness) to slight eschar formation (injuries in depth): 4
Total possible erythema score: 4

Edema formation
- No edema: 0
- Very slight edema (barely perceptible): 1
- Slight edema (edges of area well defined by definite raising): 2
- Moderate edema (raised approximately 1 mm): 3
- Severe edema (raised more than 1 mm and extending beyond area of exposure): 4
Total possible edema score: 4

Primary Irritation Score
0 Non irritating
0.1 - 0.5 Minimally irritating
0.6 - 1.5 Slightly irritating
1.6 - 3.0 Mildly irritating
3.1 - 5.0 Moderately irritating
5.1 - 6.5 Severely irritating
6.6 - 8.0 Extremely irritating






Results and discussion

In vivo

Resultsopen allclose all
Irritation parameter:
primary dermal irritation index (PDII)
Basis:
other: The scores read after 24 and 72 hours for erythema and edema for the intact as well as for the abraded skin were summed up and divided by 4. (FHSLA § 191.11)
Time point:
other: 24/72 hours
Score:
1.5
Max. score:
8
Reversibility:
fully reversible
Remarks on result:
other: slightly irritating
Irritation parameter:
edema score
Remarks:
shaved
Basis:
mean
Time point:
24 h
Score:
0.83
Max. score:
4
Reversibility:
fully reversible within: 72 h
Remarks on result:
no indication of irritation
Irritation parameter:
erythema score
Remarks:
shaved
Basis:
mean
Time point:
24 h
Score:
1.17
Max. score:
4
Reversibility:
fully reversible within: 72 h
Remarks on result:
no indication of irritation
Irritant / corrosive response data:
A slight to well-defined erythema and a very slight to slight oedema were seen an all rabbits 24 hours after application of the compound. By 72 hours all intact sites were normal but 4/6 abraded sites were still showing a slight reaction. These were normal by day 10. The primary Irritation score was 1.5.

Applicant's summary and conclusion

Interpretation of results:
GHS criteria not met
Conclusions:
A slight to well-defined erythema and a very slight to slight oedema were seen an all rabbits 24 hours after application of the compound. By 72 hours all intact sites were normal but 4/6 abraded sites were still showing a slight reaction. These were normal by day 10. The primary Irritation score was 1.5.

According to GHS, the test substance is not irritating to skin.
Executive summary:

The skin irritation in albino rabbits after single application was performed to determine the irritant potency of the test item on the albino rabbit skin.The test was carried out according to the method given in the “Hazardous Substances Regulations" under the U.S. Federal Hazardous Substances Labelling Act Sect. 191.11 (February 1965).

The test was performed on 3 male rabbits and 3 female rabbits (New Zealand White rabbits), checked for normal skin conditions. Before treatment, the flanks of the rabbits were shaved and immediately before treatment, the shaven skin on one side was slightly scarified. A gauze patch bearing 1 g of the test substance was applied to the prepared abraded and intact skin. The patches were covered by an impermeable material. Patches were held in place for 24 hours.

A slight to well-defined erythema and a very slight to slight oedema were seen an all rabbits 24 hours after application of the compound. By 72 hours all intact sites were normal but 4/6 abraded sites were still showing a slight reaction. These were normal by day 10. The primary Irritation score was 1.5.

According to the GHS evaluation system, the test substance is not irritating to skin.