Assessing Detergent Residuals for Reusable Device Cleaning Validations

Cleaning chemistries are detergent-based formulations that are used during the processing of reusable medical devices. Manufacturers are responsible for demonstrating the safety of cleaning formulations when they are used during a device processing cycle, including the risk of device-associated cytotoxicity over the concentration ranges for recommended use and rinsing during cleaning. However, no regulation currently exists requiring manufacturers to demonstrate such safety. Although manufacturers' safety data sheets (SDSs) provide information on the safe use of chemicals for users, this information may not provide sufficient detail to determine the risks of residual chemicals on device surfaces. SDSs are not required to contain a comprehensive list of chemicals used, only those of risk to the user. They should be supplemented with information on the correct concentrations that should be used for cleaning, as well as instructions on the rinsing required to reduce the levels of chemicals to safe (nontoxic) levels prior to further processing. Supporting data, such as toxicity profiles or cytotoxicity data that support the instructions for use, would provide medical device manufacturers and healthcare personnel with the necessary information to make informed decisions about selection and correct use of detergents. In the current work, cytotoxicity profiles for eight commonly used cleaning formulations available internationally were studied. Although all of these products are indicated for use in the cleaning of reusable medical devices, results vary across the serial dilution curves and are not consistent among detergent types. The information presented here can be leveraged by both medical device manufacturers and processing department personnel to properly assess residual detergent risks during processing. This work also serves as a call to cleaning formulation manufacturers to provide this information for all chemistries.