A review of critical factors in the conduct and interpretation of the human repeat insult patch test.

This paper reviews key factors that are critical to the conduct and interpretation of Human Repeat Insult Patch Tests (HRIPTs). A methodology for HRIP testing is described and general guidelines for evaluation of responses indicative of induction and elicitation of skin sensitization and skin irritation are detailed. Understanding and applying these key factors is crucial to the design of such studies and reliability of the resulting data when used in the overall risk assessment process.