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:
5 October 1992 - 22 October 1992
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: The study is performed according to OECD guidelines and GLP.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1993
Report Date:
1993

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 404 (Acute Dermal Irritation / Corrosion)
GLP compliance:
yes

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
Name: Trigonox 141
CAS No.: 13052-09-0

Test animals

Species:
rabbit
Strain:
New Zealand White
Details on test animals and environmental conditions:
TEST ANIMALS
- Source: Rosemead Rabbits, Rosemead, Waltham Abbey, Essex, England
- Age at study initiation: appr. 3 months
- Weight at study initiation: 2.48 - 2.63 kg
- Housing:individually housed in suspended stainless steel cages mounted in mobile batteries (Modular Systems and Development Company Limited, London, England).
- Diet (e.g. ad libitum): ad libitum, standard pelleted rabbit diet (S.Q.C. Rabbit Diet, Special Diets Services Limited, Witham, Essex, England).
- Water (e.g. ad libitum): ad libitum
- Acclimation period: 7 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 18-20
- Humidity (%): 44-52
- Air changes (per hr): 15
- Photoperiod (hrs dark / hrs light):12/12

IN-LIFE DATES: 5 October 1992 - 22 October 1992

Test system

Type of coverage:
semiocclusive
Preparation of test site:
other: clipped
Vehicle:
unchanged (no vehicle)
Controls:
other: untreated flank
Amount / concentration applied:
TEST MATERIAL
- Amount(s) applied (volume or weight with unit): 0.5 ml
- Concentration (if solution):as such
Duration of treatment / exposure:
4 hours
Observation period:
Assessment of skin irritation responses at the control and treated test sites were made 1, 24, 48 and 72 hours after removal of the
bandages.
Number of animals:
3 males
Details on study design:
TEST SITE
- Area of exposure: dorsum
- % coverage: 6x6 cm
- Type of wrap if used: A single dose (0.5 ml) was applied directly to the skin and covered by an unmedicated gauze patch (3 x 2 cm) which was held in place on the left test site by strips of Blenderm (Community Care Products, 3M Health Care, Loughborough, England). The right test site, acting as a control, was covered by a similar semi-occlusive dressing but otherwise remained untreated. Pads of cotton wool and elasticated bandage were used to protect the patches and ensure good contact between the skin and the test material during the four-hour exposure
period. The elasticated bandage was held in place by thin strips of waterproof plaster ('Blenderm') at both edges.

REMOVAL OF TEST SUBSTANCE
- Washing (if done): The treatment sites were gently washed with warm water and
dried with paper towels to remove excess test material adhering to the skin.
- Time after start of exposure: The dressings were removed after four hours exposure.

SCORING SYSTEM:
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

Oedema formation
No oedema 0
Very slight edema(barely perceptible) 1
Slight edema(edges of the area well defined by definite raising) 2
Moderate edema(raised approximately 1mm) 3
Severe edema( raised more than 1 mm and extending beyond the area of exposure) 4

Results and discussion

In vivo

Resultsopen allclose all
Irritation parameter:
erythema score
Basis:
mean
Remarks:
all animals
Time point:
other: 24-48-72 hours
Score:
0.77
Max. score:
4
Reversibility:
fully reversible within: 9 days
Irritation parameter:
edema score
Basis:
mean
Remarks:
all animals
Time point:
other: 24-48-72 hours
Score:
0
Max. score:
4
Irritant / corrosive response data:
Very slight erythema was observed in all rabbits during the first 24 hours after bandage removal, continuing in two rabbits up to the 72 hour examination. The test site of all rabbits was tacky during the first 24 hours of the observation period and in two animals throughout the first week. This effect was considered to have been caused by dose material that remained adhered to the test site after the washing procedure. The test sites of all animals were overtly normal by Day 9. The control sites did not show any response to the control procedure.

Any other information on results incl. tables

Summary of dermal lesions (following 4-h application) on intact skin

 

no.

Effect

Hour

Days after application

Mean score erythema

24/48/72 h

Mean score oedema

24/48/72 h

1

1

2

3

6

9

 

 

1

Erythema/ eschar

Oedema

0

*

0

1

*

0

1

*

0

1

*

0

0

*

0

0

 

0

1

 

 

0

2

Erythema/ eschar

Oedema

1

*

0

1

*

0

0

*

0

0

*

0

0

*

0

0

 

0

0.33

 

 

0

3

Erythema/ eschar

Oedema

1

*

0

1

*

0

1

*

0

1

 

0

0

 

0

    0

 

    0

1

 

 

0

*Test site tacky

Applicant's summary and conclusion

Interpretation of results:
not irritating
Remarks:
Migrated information Criteria used for interpretation of results: EU
Conclusions:
The test substance is not irritating to skin. No oedema occured and the mean score for 24-48-72 hours for erythema is =< 1.5 for all animals.
Executive summary:

The potential the substance to cause inflammatory or corrosive changes upon first contact with skin was assessed by semi-occluded application of 0.5 ml of the test material to the closely-clipped dorsa of three New Zealand White rabbits for four hours. Dermal reactions were assessed 1, 24, 48 and 72 hours and six and nine days after removal of the dressings. Very slight erythema was observed in all rabbits during the first 24 hours after bandage removal, continuing in two rabbits up to the 72 hour examination.

Residual dose material adhered to the test site for up to six days. The test sites of all animals were overtly normal by Day 9. The test substance is not irritating to skin.