Skin Tolerance Tests

User Studies

[With new formulations it is advisable to conduct an irritancy patch test prior to these tests.]

User Trials

Designed to give reassurance that under conditions of everyday use products do not produce any adverse skin reactions. Information can also be gained about product usage and consumer opinion by use of questionnaires.

• Large panels available, 50, 100 or greater
• One, two or three weeks use of product
• Cross over studies possible for within subject comparisons

Sensitive Skin User Trials

Subjects taking part in user studies can be selected on the basis of having sensitive skin. The selection can be based on questionnaire (self perception) or on chemical sensitivity (reaction to standard irritant).

Arm and Facial Wash Test

These tests are designed to exaggerate actual product usage under controlled laboratory conditions. Subjects return daily or twice daily for arm (forearm or flexural aspect of forearm – flex test) or facial washing using a standard procedure. Skin reactions are assessed daily. Tests give reassurance that under conditions of normal use the product performs as it should and is unlikely to cause skin reactions.

• Normally 25 subjects
• Five days usage
• Suitable for leave on products
• Two products normally compared, left arm – right arm comparison or split face design

Hand Immersion Test

This test is designed specifically for hand wash products. Repeated exposure to hand wash products often leads to eczema like skin changes specific to the hand. Twice daily immersion over a five-day period exaggerates the exposure to a product. The test gives reassurance that under actual use conditions the product causes minimal skin problems.

• Normally 25 or 50 subjects
• Five days usage
• Two products can be compared, left hand – right hand comparison
• Dermatologist assessment of skin of hands before and after use

Wash and Wear Test (clothing test)

Residuals left behind by washing powders and conditioners may increase the risk of skin irritation from clothing. These tests on infants or adults give reassurance that products do not leave potentially irritant residues on clothing.

• Normally 25 or 50 infants or adult subjects
• Two weeks wearing of garments next to skin (e.g. vest or babygro)
• Dermatologist assessment of skin before and after use

Wear Test (nappies)

Panels of infants are available to assess the in use performance and safety of nappies and disposable training pants. These tests give reassurance that products are not potentially irritant under conditions of everyday use.

• Normally 25 or 50 infants subjects
• Two weeks wearing of disposables (e.g. nappies or pull ups)
• Dermatologist assessment of skin before and after use