48-Hour Patch Test
Outline: 48-Hour Patch Test

To determine the irritation potential of a test article or series of test articles after a single 48-hour patch exposure to the skin of human subjects.


50, 100 or 200 healthy men and women


5-day test
Start test within 2 days - 1 week after receipt of sample
Report issued within 3 weeks of study completion

Quantity: 4 oz. per 50 subjects

Clinical assessment of skin response by a trained evaluator

Approximately 0.05 mL or grams of each test article is applied to the test patch (absorbent discs affixed to occlusive or semi-occlusive adhesive tape). The patches are applied to the subject's back, the upper arm and/or the volar surface of the forearm.

Forty-eight hours after application, patches are removed and the test sites are scored by a trained ETC examiner. The sites are again scored 72 or 96 hours after application.

Skin responses are scored according to the following 6-point scale:
0 = (None) No evidence of any effect.
+ = (Barely perceptible) Minimal, faint, uniform or spotty erythema.
1 = (Mild) Pink, uniform erythema covering most of the contact site.
2 = (Moderate) Pink-red erythema, uniform in the entire contact site.
3 = (Marked) Bright red erythema with/without petechiae or papules.
4 = (Severe) Deep red erythema with/without vesiculation or weeping.

Accompanying edema (swelling) at any test site is recorded with an "e" and described as mild, moderate or severe. Other possible dermal sequelae are similarly recorded.

The subjects are asked to report any delayed reactions which might occur after the last reading. At the Sponsor's option, and for an additional fee, readings may be taken at additional time periods after application, and/or until disappearance of the reaction.