Cross-Contamination

Unintended substance transfer leading to impurity introduction

A contaminant is defined in PDA TR29, Points to Consider for Cleaning Validation, as "An undesired residue or residue level on cleaned equipment surfaces or in a manufactured product" In the case of cross-contamination, the contaminant is transfered from one process into another or from an outside source such as an operator or HVAC system. The cross contamination is typically detected in the product where batch rejection may occur based on an impact assessment. Current good manufacturing practices, ICH Q7, requires a contamination control strategy to be written at the facility to control the risk of all forms of contamination to an accepted level.