Chemical characterization involves the identification of a material and the identification and quantification of its chemical constituents. as part of an assessment of the overall biological safety of a medical device. It involves a measurement of the level of a leachable substance in a medical device in order to allow the assessment of compliance with the allowable limit derived for that substance from health based risk assessment, to determine equivalence of a proposed material to another material or to another final device / prototype, or for screening of potential new materials for suitability in a medical device for a proposed clinical application.