HRIPT (Marzulli and Maibach)

A Marzulli Maibach Human Repeat Insult Patch Test is used to determine the delayed skin sensitisation potential of test materials. Test materials are applied under occlusive patch conditions, in a panel of 50 healthy human volunteers.

Volunteers have the test materials applied to their arm or back for 9 periods of 47h, over an induction period of 3 weeks. Each induction site is evaluated for erythema and oedema after removal of the patch.

Two weeks after the last induction, a challenge patch is applied for approx 47h and subsequently read 1 h after patch removal, then again at 72h and 96h.

The response after challenge is compared to the responses reported after the early induction patches. The induction patch responses are also noted and interpreted as evidence of cumulative irritation.