Hierarchy of Controls

The Hierarchy of Controls is the order in which controls should be considered:

• Elimination & substitution. First, try to eliminate the hazard.
• Engineering controls. Next try to reduce the hazard. Engineering controls aim to effectively minimize the risk.
• Administrative controls. Next try to manage the hazard. Administrative controls aim to effectively navigate through the risk.
• Personal Protective Equipment (PPE). Finally, provide a barrier between the worker and the hazard that can't be reasonably eliminated, reduced or managed further.

The first control required is to determine if the silica process is necessary to complete the work, or if some or all of the risk of the silica process can be eliminated by replacing the silica process with a less hazardous alternative. If it is not possible to reasonably eliminate the silica process, then the employer must control the exposure level below the exposure limit.

For many silica processes, effective controls are available to protect workers from hazardous exposure. A combination of control measures is often required to bring exposure levels below the exposure limit. Control measures come with recommended practices about how to use the controls properly for effective results.

Note: the use of PPE such as respirators as a primary control is not permitted when other means of control are practicable to use. PPE is permitted as additional control only where engineering and administrative controls are inadequate to control exposure below the exposure limit. In situations where dust can be controlled below the exposure limit with engineering and administrative controls, the use of respirators may not even be necessary.