Equipment (parts or members) whose failure to function as intended can result in a release of fluids to the environment.
Source: API Specification 16Q, Design, Selection, Operation, and Maintenance of Marine Drilling Riser Systems, Second Edition, April 2017. Global Standards
Equipment [part(s) or member(s)] exposed to wellbore fluids whose failure to function as intended can result in a release of wellbore fluid to the environment.
Source: API STD 53, Blowout Prevention Equipment Systems for Drilling Wells, Upstream Segment, Fourth Edition, November 2012. Global Standards