Advanced Safety Management, 3rd Edition

CHAPTER 11HIERARCHIES OF CONTROL

A hierarchy is a system of persons or things ranked one above the other. Hierarchies of control in Z10.0 and 45001 provide

• A systematic way of thinking, considering steps in a ranked and sequential order;
• An effective way for decision makers to eliminate or reduce hazards and the risks that derive from them.

Acknowledging the premise—that risk reduction measures should be considered and taken in a prescribed order—represents an important step in the evolution of the practice of safety. A major premise in applying a hierarchy of controls is that the outcome of the actions taken is to be an acceptable risk level, defined as follows:

Acceptable risk is that risk for which the probability of a hazard-related incident or exposure occurring and the severity of harm or damage that could result are as low as reasonably practicable in the situation being considered.

That definition requires taking into consideration each of the two distinct aspects of risk as decisions are made to reduce risks:

• Avoiding, eliminating, or reducing the probability of a hazard-related incident or exposure occurring
• Reducing the severity of harm or damage that may result, if an incident or exposure occurs

HIERARCHIES OF CONTROL IN 45001 AND Z10.0

Requirements in the hierarchies of control in the 45001 and Z10.0 standards are close to identical, but not quite. In 45001, under the subcaption “Eliminating Hazards and Reducing OH&S Risks” (Section 8.1.2), this is the ...