QEHSRisk
Hierarchy of Controls
The ranked order of effectiveness for controlling workplace hazards.
NIOSH and ISO 45001 recognise five levels: (1) Elimination — remove the hazard entirely; (2) Substitution — replace with a less hazardous alternative; (3) Engineering controls — isolate people from the hazard; (4) Administrative controls — change the way people work; (5) PPE — protect the individual. More effective controls are at the top. PPE is a last resort, not a primary control.