The United States Pharmacopeia (USP) establishes standards to ensure the quality of medicines and other healthcare technologies.
These include biological reactivity tests for "elastomerics, plastics and other polymeric material with direct or indirect patient contact", which are divided into six classes.
Class VI has the most stringent testing and is widely used and accepted in the medical products industry.
Please note that USP Class VI testing does not fully meet any category of ISO 10993-1 testing guidelines currently used by the US FDA for medical device approval, and developers of medical products maintain responsibility for ensuring the suitability of a raw material for its end use.