 These formulations each meet U.S. Food and Drug Administration 3-A and NSF International 51 criteria but they do not comply with European Directives (European Directive 2002/72/EC of 6 August 2002 relating to plastic materials and articles intended to come into contact with foodstuffs as modified in particular by Directive 2007/19/EC of 2 April 2007).Several formulations of Tygon are USP class VI approved and can be used in either surgical procedures or pharmaceutical processing.