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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:
15 Apr - 06 May 2008
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2008
Report date:
2008

Materials and methods

Test guideline
Qualifier:
according to guideline
Guideline:
OECD Guideline 404 (Acute Dermal Irritation / Corrosion)
Version / remarks:
Adopted 24 Apr 2002
Deviations:
no
GLP compliance:
yes (incl. QA statement)
Remarks:
The Department of Health of the Government of the United Kingdom, London, England

Test material

Constituent 1
Chemical structure
Reference substance name:
Pyridine-2-carboxylic acid
EC Number:
202-719-7
EC Name:
Pyridine-2-carboxylic acid
Cas Number:
98-98-6
Molecular formula:
C6H5NO2
IUPAC Name:
pyridine-2-carboxylic acid
Test material form:
solid: particulate/powder

Test animals

Species:
rabbit
Strain:
New Zealand White
Details on test animals or test system and environmental conditions:
TEST ANIMALS
- Source: Harlan UK Ltd, Bicester, Oxon, UK
- Age at study initiation: 12-20 weeks
- Weight at study initiation: 2.0-3.5 kg
- Fasting period before study: None
- Housing: individually in suspended cages, and provided environmental enrichment items
- Diet: "Certified Rabbit Diet," not further specified, ad libitum
- Water: mains drinking water, ad libitum
- Acclimation period: at least five days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 20 ± 3
- Humidity (%): 30-70
- Air changes (per hr): ≥15
- Photoperiod (hrs dark / hrs light): 12/12

IN-LIFE DATES: From: 15 Apr 2008 To: 06 May 2008

Test system

Type of coverage:
semiocclusive
Preparation of test site:
clipped
Vehicle:
other: test substance was moistened with distilled water
Controls:
no
Amount / concentration applied:
TEST MATERIAL
- Amount(s) applied: 0.5 g

VEHICLE
- Amount(s) applied: 0.5 mL distilled water was added to moisten the test substance
Duration of treatment / exposure:
3 min, 1 and 4 h
Observation period:
7 days
Reading time points: 1, 24, 48 and 72 h, and 7 days after removal of test substance
Number of animals:
3
Details on study design:
TEST SITE
- Area of exposure: 2.5 cm² on the dorsal area of the trunk of each animal
- % coverage: not specified
- Type of wrap if used: The test substance was introduced under cotton gauze patches on the shorn skin, secured in place with a strip of surgical adhesive tape, and then the trunk of each animal was wrapped in an elasticized corset.

REMOVAL OF TEST SUBSTANCE
- Washing: Residual test substance was removed by gentle swabbing with cotton wool soaked in distilled water.
- Time after start of exposure: preliminary animal: 3 min, 1 and 4 h, additional 2 animals: 4 h

OBSERVATION TIME POINTS
- 1, 24, 48 and 72 h, and 7 days

SCORING SYSTEM:
- Method of calculation: Draize scoring system

Results and discussion

In vivo

Resultsopen allclose all
Irritation parameter:
erythema score
Basis:
animal #1
Time point:
24/48/72 h
Score:
2
Max. score:
4
Reversibility:
fully reversible within: 7 days
Irritation parameter:
erythema score
Basis:
animal #2
Time point:
24/48/72 h
Score:
2
Max. score:
4
Reversibility:
not fully reversible within: 7 days
Irritation parameter:
erythema score
Basis:
animal #3
Time point:
24/48/72 h
Score:
1.67
Max. score:
4
Reversibility:
fully reversible within: 7 days
Irritation parameter:
edema score
Basis:
animal #1
Time point:
24/48/72 h
Score:
1
Max. score:
4
Reversibility:
fully reversible within: 7 days
Irritation parameter:
edema score
Basis:
animal #2
Time point:
24/48/72 h
Score:
1.67
Max. score:
4
Reversibility:
fully reversible within: 7 days
Irritation parameter:
edema score
Basis:
animal #3
Time point:
24/48/72 h
Score:
0.67
Max. score:
4
Reversibility:
fully reversible within: 7 days
Irritant / corrosive response data:
In two animals, light brown discolouration of the epidermis was noted as an erythema reading at the 72 h time point. Concurrently, loss of skin elasticity was noted for one of these 2 animals at the same evaluation.
An observation of desquamation was noted at 7 days in one animal, however the skin reaction itself scored a zero, supporting the criteria of full reversibility within 7 days for all animals.

Any other information on results incl. tables

Table 1: Results of Dermal Irritation Evaluation in the Rabbit after Exposure to the Test Substance

Observation time

1

2

3

 

Erythema

Edema

Erythema

Edema

Erythema

Edema

1 h

0

0

1

0

1

0

24 h

2

1

2

2

2

1

48 h

2

1

2

2

2

1

72 h

2

1

2BL

1

1B

0

7 days

0

0

0D

0

0

0

Mean value
24 + 48 + 72 h

2.00

1.00

2.00

1.67

1.67

0.67

B = Light brown discolouration of the epidermis

L = Loss of skin elasticity

D = Desquamation

Primary Irritation Index (S/6): 17/6 = 2.6

Applicant's summary and conclusion

Interpretation of results:
other: no classification required according to Regulation(EC) No. 1272/2008.
Conclusions:
The observed Draize scores do not indicate skin irritation potential of picolonic acid. Therefore, no classification is required for picolinic acid according to Regulation(EC) No. 1272/2008.

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