Using extractables and leachables chemistry testing to support biocompatibility assessments and cleaning validations for medical devices is now widely accepted, but it remains a moving target as the approaches develop. A variety of chemical characterization strategies are now available with differing degrees of scientific rigor and diverse regulatory body acceptance. New regulatory draft documents will aide manufacturers in the selection of the application, including the recently published standard ISO 18562 that addresses gas path devices. This presentation will provide a brief overview of the goals of chemical characterization, current approaches, and anticipated changes based on our involvement in industry committees. Attendees will leave informed about how and why we do chemistry testing for medical devices.