Patch Test Methods

Patch testing helps you assess the tolerability of your cosmetic products and it reveals any potential irritants and allergic effects. The QACS Laboratory dermatological compatibility tests are in line with the guidelines on the use of human volunteers in compatibility testing of finished cosmetic products. These include patch tests and human repeated insult patch tests (HRIPT).

Our Patch Test Methods

We carry out established patch protocols such as patch tests and human repeated insult patch tests (HRIPT) based on current guidelines, to assess non-irritant and hypoallergenic claims for cosmetics.

The patch test is conducted on 10, 12, 20 or 30 volunteers. However, you can customise the number of your volunteers depending on your needs.

During a patch test we apply a trace of the ingredient or the finished product on an occlusive patch. We then apply the patch on the adult volunteers, directly on the skin of their back, for 48 hours.

Our experienced dermatologists perform a clinical observation of the effects on the skin after the patch is removed. The irritant potential is ranked based on a predetermined scale that corresponds to the degree of irritation.

The results are classified as:

  • Negative (-)
  • Irritant reaction (IR)
  • Equivocal / uncertain (+/-)
  • Weak positive (+)
  • Strong positive (++)
  • Extreme reaction (+++)

We use the human repeated insult patch test (HRIPT) to examine skin compatibility and the absence of allergic potential of cosmetic products. This is assessed after repeated application to the skin under extreme experimental conditions.

Our dermatologists:

  • Apply the patch with the product directly on the skin of the volunteers for a specific period of time.
  • Repeat the applications 9 times over a period of 3 consecutive weeks, which is the period necessary for possible induction of an allergy.
  • Allow for a rest period of at least 2 weeks without any patch applications.
  • Proceed with a single application of a patch on the previous induction site and on a virgin site for a specific period of time.
  • Check for possible induced allergies upon removal of the patches.

What we offer

Under the supervision of experienced dermatologists, we offer:

  • Customised patch tests
  • Dermatological evaluations
  • Pool of 1200 volunteers, male & female, aged 18 to 65, with different skin types

You can also customize your patch test panel depending on your needs.

Our compliance with regulatory requirements

  • Regulation (EC) no 1223/2009 – On cosmetic products.
  • Regulation (EC) no 655/2013 – On common criteria for the justification of claims used in relation to cosmetic products, including truthfulness, evidential support and honesty.
  • SCCS Notes – SCCS notes of guidance for the testing of cosmetic ingredients and their safety evaluation.

Have a question? We can help find an answer

Fill in our contact form below to request our price list and find out how our QACS Laboratory team can help you.