Hierarchy Of Hazard Controls

Controlling hazards and behaviors are the two basic strategies for protecting workers. Controlling hazards are more effective than controlling behaviors, and for good reason. If you can eliminate the hazard, you don’t have to worry about exposure due to human behavior. Traditionally, a “Hierarchy of Controls” has been used as a template for implementing feasible and effective controls.

ANSI Z10-2012, Occupational Health and Safety Management Systems, encourages employers to employ the following hierarchy of hazard controls:

Controlling Hazards

1. Elimination: “Design out” hazards and hazardous exposures.

2. Substitution: Substitute less-hazardous materials, processes, operations, or equipment.

3. Engineering controls: Isolate process or equipment or contain the hazard.

Controlling Behaviors

4. Warnings: To raise awareness of the hazards to which employees may be exposed, warnings in the form of signs, placards, cones, and barriers are used.

5. Personal protective equipment: Includes but is not limited to safety glasses for eye protection; ear plugs for hearing protection; clothing such as safety shoes, gloves, and overalls; face shields for welders; fall harnesses; and respirators to prevent inhalation of hazardous substances.

As you can see, the preferred control strategies is to first try to control hazards through elimination, substitution, or engineering. If the hazards can’t be eliminated, replaced, or engineered, the hierarchy next attempts to control exposure to hazards through administrative methods and personal protective equipment. It’s important to understand that:

Elimination, substitution, and engineering controls are independent: they do not rely on behavior to be effective: that’s why they are preferred.
Warnings, administrative, work practice, and PPE controls are dependent: they rely on compliant human behavior to be effective. Any solution that relies on human behavior is inherently unreliable in the long term.

The “big idea” behind this hierarchy is that the control methods at the top of the list are potentially more effective and protective than those at the bottom. Following the hierarchy of controls leads to the implementation of inherently safer workplace environments, where the risk of illness or injury has been substantially reduced