For the validation of the cleaning of a medical device, a cleaning limit needs to be established for each residual processing agent. The cleaning limit is the level below which the residual processing agents pose no risk to the patient. Traditionally this is done by performing a toxicological assessment following ISO 10993-12 on each individual processing agent (and each component of a processing agent if it is a mixture) and setting a cleaning limit for each chemical. When the total number of possible chemicals from the processing agents is small (less than 10) and all have toxicological data available, this is the preferred approach. Unfortunately, this is commonly not the case. If the manufacturer is faced with a large number of potential chemical residues from the processing agents (greater than 10), the time and cost of a complete toxicological assessment to set the cleaning limit of each component may be prohibitive. Also, complete toxicological data may not be available in the literature which could prevent the determination of the cleaning limit for a specific compound.
At Pine Lake Laboratories we have developed an approach to assist medical device manufacturers when faced with the challenging task of setting cleaning limits for a large number of potential contaminants from process agents or when complete toxicological data is not available. Our approach is to set a worst case scenario cleaning limit and then testing the medical device by a battery of sensitive analytical techniques to determine which of the potential contaminants are actually present on the device at a level that could potentially present a risk to the patient.
