About

Patch test for Tint, Henna or Laminating. The 48-hour Patch Test, also known as the Primary Irritation Test, is a simple trial to assess a product’s likelihood of causing irritation. Patches containing the test product in varying concentrations are applied to the panelist’s skin. The patches remain on the skin for 48 hours (2 days), and then the panelist returns to the testing site for patch removal. After patch removal, the site is evaluated immediately and 2 days later for redness, dryness, and other indicators of irritation.