Elimination & Substitution

Elimination & substitution is the removal of the hazard by eliminating the silica process, or the replacement of the hazard by substituting the material or equipment with less RCS dust producing alternatives.

Elimination & substitution are the most effective methods to removing the hazard from a workplace because it is not possible to consider every factor that could influence the effect that RCS dust exposure may have on an individual worker. Even very low exposure levels can present a risk. Due to a wide variation in individual susceptibility, some workers may experience discomfort from concentrations at or below the exposure limit. Others may be affected more seriously by aggravation of a pre-existing condition, or by development of an occupational disease. Furthermore, other workplace contaminants may affect an individual worker's response to RCS dust exposure. The effects of combined chemical exposures are often unknown or poorly defined. No exposure to RCS dust is the only truly safe exposure level.

To eliminate or reduce the need for a given silica process, substitution alternatives to consider include:

• Use designs and standards that minimize the need for silica processes at the mine.
• Substitute the task and/or tool with a less dust producing alternative or with a higher efficiency. The more energy being imparted into a silica-containing material, the greater the airborne concentration of silica dust.
• Substitute the material with an alternative that contains a lower percentage of (or no) crystalline silica.

If it is not practicable to eliminate or reduce the risk of worker exposure, the risk must be controlled below the exposure limit.