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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
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Pre-dates GLP and pre-dates current guideline. Similar to OECD 404 but reversibility not fully investigated.

Data source

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

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
other: Federal Register No. 38. 187 ยง 1500.41 (skin) side of 27 27 019 Sept. 1973 evaluation key to Draize, J.H. (1959) DERMAL TOXICITY
Deviations:
not specified
Principles of method if other than guideline:
Study method was similar to OECD 404, Acute Dermal Irritation/Corrosion. Testing was performed on 6 New Zealand White rabbits on both abraded and unabraded skin sites with occlusive dressings. Treatment was for 24 hours. Following removal of the patches the animals were scored for erythema and eschar formation and oedema according to the grading system in OECD 404 at 24 and 72 hours post dose. The animals were killed 7 days post dose and a necropsy examination of the skin performed.
GLP compliance:
not specified

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
The test material was a liquid. Lot or batch number was not specified. Inbifo number was S 2575 A1. Purity was not specified.

Test animals

Species:
rabbit
Strain:
New Zealand White
Details on test animals and environmental conditions:
Six male and female NZW rabbits were acclimatised for more than 3 days before the start of the study. The animals weighed 3 to 4 kg. They were housed in a permanent building, fully air-conditioned with filtered air. There was a 12 hour light/dark light cycle from 07:00 am to 19:00 pm. The temperature was 22+/- 1 degree C and the humidity was 55 +/- 10%. The animals were housed in stainless steel cages without litter. Standard laboratory pelleted diet and tap water were available ad-libitum.

Test system

Type of coverage:
occlusive
Preparation of test site:
other: Test site was shaved and both abraded and non-abraded skin tested.
Vehicle:
unchanged (no vehicle)
Controls:
other: untreated skin on test animals
Amount / concentration applied:
0.5 ml
Duration of treatment / exposure:
24 hours
Observation period:
graded up to 72 h post dose. Animals killed at 7 d post dose and necropsy examination of skin performed.
Number of animals:
6
Details on study design:
Hair was shaved on both sides of the spine using electric hair clippers, approximately 16 hours before application. The application site was ca. 2.5 cm x 2.5 cm = 6.25 cm2. Untreated skin was used as a negative control.
The left side was abraded over an area of ca. 6.25 cm2, with 5 vertical lines.
A tuberculin syringe was used for the application of 0.5 ml of unchanged test material. Following application to the skin the site was covered with 2 layers of gauze (2.5 cm x 2.5 cm in size). These were held onto the skin with elastic bandage. This was held in place with PVC film and adhesive tape. The exposure time was 24 hours.
Scoring of the test sites was performed according to the Draize method (see table below).
The test sites were scored at 24 and 72 h post dose. After 7 days post dose the animals were killed and a necropsy examination of the skin was performed for the assessment of the intact and abraded skin, subcutaneous tissues and musculature at the application sites.

Results and discussion

In vivo

Results
Irritation parameter:
overall irritation score
Basis:
mean
Score:
0.54
Reversibility:
other: necropsy examination performed at 7 days post dose.
Remarks on result:
other: necropsy examination of intact and abraded skin, subcutaneous tissue and underlying muscle were without findings for all animals.
Irritant / corrosive response data:
Overall mean was 0.54. Classified as not irritating.
Other effects:
A yellowish discolouration of the skin at the application sites was reported - this was possibly the test material.

Any other information on results incl. tables

Assessment levels and calculated irritation index โ€“ irritation grades

 

 

Rabbit number

 

 

 

Time after application

(h)

1

2

3

4

5

6

Aggregate value

Mean

Erythema and Eschar formation

Intact skin

24

 

 

0

0

0

0

0

0

0

0

72

1

1

1

0

1

0

4

0.67

Erythema and Eschar formation

Abraded skin

24

 

 

0

0

1

1

0

1

3

0.5

72

1

1

1

1

1

1

6

1.0

Oedema formation

Intact skin

24

 

0

0

0

0

0

0

0

0

72

0

0

0

0

0

0

0

0

Oedema formation

Abraded skin

24

 

0

0

0

0

0

0

0

0

72

0

0

0

0

0

0

0

0

Necropsy findings

Rabbit 1

intact and scarified skin:

Subcutaneous tissue and underlying muscles without findings

Rabbit 2

Findings as for rabbit 1

Rabbit 3

Findings as for rabbit 1

Rabbit 4

Findings as for rabbit 1

Rabbit 5

Findings as for rabbit 1

Rabbit 6

Findings as for rabbit 1

Applicant's summary and conclusion