Hierarchy of Controls
OSHA's ranked order for addressing a workplace hazard, from most effective to least: eliminate the hazard entirely, replace it with something safer, engineer the risk out with equipment or design, use administrative controls like training and procedures, and only then rely on personal protective equipment as the last layer of defense.
Why it matters
PPE sits deliberately last in this order, not because it doesn't matter, but because it's the least reliable control: it only works if it's worn correctly every time, while eliminating or engineering out a hazard protects a worker even if they make a mistake. Understanding this order explains why safety programs push so hard on the controls that come before PPE.
On a real project
Rather than relying solely on respirators to protect workers from concrete dust, a crew first tries to control the hazard higher up the hierarchy by using a vacuum-attached saw that captures dust at the source, an engineering control, and only relies on the respirator as a backup layer.
Who this matters most to
A Safety Manager applies the hierarchy of controls when designing a safety program, prioritizing fixes that remove a hazard over fixes that just protect the worker from it.
Where this goes wrong
A jobsite handles a persistent hazard, like excessive noise from a piece of equipment, entirely through hearing protection rather than considering whether the equipment itself could be replaced or isolated. Workers inconsistently wear the protection correctly, and the underlying hazard never actually goes away.