161 Industrial Hygiene: Basic

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 top three strategy areas (elimination, substitution, and engineering controls) attempt to eliminate or reduce the hazards themselves. After all, if you can get rid of the hazard, there's no need to control employee exposure to the hazard if it doesn't exist. Let's look at the first three strategies.

Elimination: This strategy completely removes the source of the hazard. Removing a noisy machine from a workstation would completely eliminate any exposure to the noise. This strategy should be considered first for all safety professionals including industrial hygienists.

Substitution: This strategy reduces the severity of the hazard. This strategy should be used if it is not feasible to eliminate the hazard. The idea is to replace the hazard with a less hazardous substitute. An example would be to replace a hazardous chemical with a non-toxic chemical. There would still be a need for protection like personal protective equipment, but the hazards of exposure would be less serious.

Engineering controls: This strategy involves the design or redesign of tools, equipment, machinery and facilities so that hazardous chemicals are not needed or that exposure to those hazardous chemicals is not possible. Examples include:

• Equipment designed so that it does not require the use of hazardous chemicals in a process or for cleaning
• Enclosing work processes to isolate hazards
• Installing general and local ventilation systems

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