Utilities and process equipment must be considered part of the process if in the event of a failure or malfunction they could potentially contribute to or fail to mitigate a process safety incident. For purposes of this definition, any group of vessels that are interconnected, or separate vessels that are located such that an incident in one vessel could affect any other vessel, must be considered a single process. This definition includes processes under partial or unplanned shutdowns.
This definition excludes ancillary administrative and support functions, including office buildings, labs, warehouses, maintenance shops, and change rooms.
Wash. Admin. Code § 296-67-307