The Hierarchy of Hazard Control Strategies
Controlling hazards and controlling behaviors are the two basic strategies for reducing risk of injury and illness in the workplace.
The Hierarchy of Controls (HOC) traditionally serves as a model to implement feasible and effective control measures.
Click on the image to see the HOC control methods. The top 3 control methods are considered first because controlling hazards to reduce risk is more predictable and effective than trying to control human behavior. Let's look at two HOC strategy levels and the methods used in each:
Controlling Hazards
- Elimination: Avoid or eliminate hazards such elevated work, hazardous materials, excessive noise, confined spaces, etc.
- Substitution: Substitute less-hazardous materials, processes, operations, or equipment. Reduce energy, lower speed, force, amperage, pressure, temperature, noise, etc.
- Engineering controls: Through design or redesign, isolate or contain hazardous processes or equipment such as ventilation systems, machine guarding, sound enclosures, circuit breakers, guardrail systems, interlocks, lift tables, etc..
Controlling Behaviors
- Warnings: Warnings are usually audible or visible. Signs, labels, posters, and lights are examples of warnings that alert workers about hazards.
- Administrative/Work Practice Controls: Manage exposure to hazards through strategies such as warning signs, alarms, scheduling work, training, and safety rules. These controls aim to minimize exposure by modifying how tasks are performed. Examples include handwashing, defensive driving, and decontaminating equipment.
- Personal Protective Equipment (PPE): PPE is used to reduce exposure. PPE 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.
HOC strategies prioritize controlling hazards primarily because their effectiveness does not depend on human behavior. In cases where hazard controls prove inadequate, the implementation of behavioral controls becomes necessary, which can complicate risk reduction efforts. The inherent challenge with behavioral controls is their reliance on human behavior, and as it's often said, 'any system solely dependent on human behavior is inherently unreliable.
Knowledge Check Choose the best answer for the question.
3-2. Which one of the two basic Hierarchy of Controls strategies is considered most effective?
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