Patch test (skin irritation)
The patch test determines whether your finished product causes irritation on the skin, in other words its skin-irritation potential.
How the test works
- A panel of 12 healthy adult volunteers takes part.
- About 0.2 g/ml of product is applied once to intact skin on the back or arm.
- It stays under an occlusive or semi-occlusive patch for 48 hours.
- Skin reactions are read 1 hour and 24 hours after the patch is removed.
Leave-on vs rinse-off
Leave-on products are tested undiluted. Rinse-off products are diluted (1%, 5% or 10%). Powders and solid products can be tested too; the application is adapted to the product type.
Timeline
About two weeks in total: we confirm the completion date after receiving your samples, run the 48-hour application, read the reactions and prepare the report (signed PDF).
Is it required?
A patch test is usually not required by cosmetics legislation, but it is advisable for all cosmetic products in most markets, especially new formulas and products used on sensitive areas. It also feeds into your CPSR. If you want to make a specific skin claim, ask us what evidence it needs.