Cleaning agent safety based limits are typically calculated from a safety factor of an acceptable daily intake (ADI), a (1/1000 or more) reduction of an LD50 preferably by the same route of administration, or reproductive hazard levels. If the calculated limit is found to be higher than a less than 10 ppm carryover to the next batch, then the limit can be set to the more stringent 10 ppm carryover level for the safety based limit.

cleaning validation Note that for many residues you can validate a visual detection limit on the order of 1-4 ug/cm2. It is possible that the visually clean criteria will be the most stringent criteria.

For more information on cleaning validation in the pharmaceutical industry, see Alconox's Cleaning Validation References.