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704 Hazard Analysis and Control
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Controlling Hazards

Traditionally, a prioritized "Hierarchy of Controls" (HOC) has been used to implement feasible and effective exposure controls to protect workers.

We encourage the use of the HOC as described within the ANSI/ASSP Z10, Occupational Health and Safety Management Systems, to control hazards. The six strategies are discussed below.

The first three strategies protect employees by physically eliminating or reducing the hazards.

  1. Elimination - completely removes the hazard
  2. Substitution - reduces or replaces the hazard
  3. Engineering Controls - modifies or isolates the hazard

The final three strategies protect employees by eliminating or reducing exposure to hazards.

  1. Warnings - raises employee awareness of the hazard
  2. Work Practice Controls - mandates safe work behaviors
  3. Personal Protective Equipment (PPE) - places barriers between the hazard and employees

The idea behind HOC is that the control strategies at the top of the list are potentially more effective and protective than those at the bottom. Following the hierarchy normally leads to inherently safer systems, ones where the risk of illness or injury has been substantially reduced. Let's take a closer look at the hierarchy of control strategies.

Interim Measures

Using a lower priority hazard control method over another higher priority control strategy may be appropriate for providing interim (temporary) protection until the hazard is abated permanently. If you can't eliminate the hazard entirely, the interim control measures will likely be a combination of control methods used together. OSHA believes that feasible interim measures are always available if higher-level control methods are not possible.

Knowledge Check Choose the best answer for the question.

5-1. Which strategy protects employees by isolating or modifying hazards?