Skin Tolerance Tests

Special Tests

Facial Stinging Test

Even if products pass standard safety tests such as irritancy and sensitisation, consumers may experience unpleasant sensations such as burning and stinging when using products. The face is the most common part of the body to experience this problem and the facial stinging test was specifically designed by Frosch & Kligman to screen for products with this tendency.

• Normally 12 subjects
• Subjects selected as having sensitive facial skin (lactic acid positive)
• Comparison with control or marketed product with known history
• Within subject comparison, left side of face versus right side

Comedogenicity Test

The formation of comedones (blackheads) is a rare side effect from prolonged use of certain facial cosmetics. This test was developed by Mills and Kligman as a human alternative to the rabbit ear test. In this test the product is held in contact with the skin of the upper back for four weeks. Skin surface biopsies are taken at the end of the study and examined microscopically for presence of micro-comedones.

• Normally 20 subjects
• Subjects selected with mild acne and therefore prone to comedones
• Comparison with control or marketed product with known history
• Within subject comparison