Cleaning validation

Documented evidence that a cleaning procedure consistently removes product residues, cleaning agents and microbial contamination from equipment to below justified limits, so that the next product is not contaminated. Limits are now usually derived from a health-based exposure limit, such as a permitted daily exposure (PDE), and converted into a maximum allowable carryover (MAC). Studies cover the worst-case product and hard-to-clean locations, use swab and rinse sampling with validated recovery, and include the dirty hold time and clean hold time. Expect questions on how each limit was derived and whether any step relies on visual inspection alone.