Pyridine-2-carboxylic acid

Skin irritation / corrosion

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

Test material information

Constituent 1

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

Results

Results 1

Irritation parameter:

erythema score

Basis:

animal #1

Time point:

24/48/72 h

Score:

2

Max. score:

4

Reversibility:

fully reversible within: 7 days

Results 2

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

Results 3

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

Results 4

Irritation parameter:

edema score

Basis:

animal #1

Time point:

24/48/72 h

Score:

1

Max. score:

4

Reversibility:

fully reversible within: 7 days

Results 5

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

Results 6

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.