Under Cal/OSHA’s Process Safety Management (PSM) standards (specifically Title 8 §5189.1 for refineries and §5110.16 for other facilities), the Hierarchy of Hazard Control Analysis (HCA) is a formal, documented requirement that goes significantly beyond the traditional OSHA “inverted pyramid.”
While standard safety protocols often treat the hierarchy as a suggestion, Cal/OSHA makes it a mandatory iterative process for reducing risk to the “greatest extent feasible.”