HOW MUCH SILICA DUST IS HARMFUL?
If you can see the dust around you - its too much dust., Using tools like air monitors or resources like Time Weighted Average and the Hierarchy of Controls, can help you determine your real exposure levels.
TIME WEIGHTED AVERAGE FOR MONITORING EXPOSURE
Time Weighted Average (TWA) is used to calculate a worker’s daily exposure to a hazardous substance averaged to an 8-hour workday, taking into account the average levels of the substance or agent and the time spent in the area. While some workers may engage in a single work practice throughout a workday, others may engage in multiple work practices. As you know, each work practice varies from high exposure to zero exposure to silica. OSHA lets us average the exposure over an 8-hour day. This averaging allows us to vary the activities a person performs to help keep them in a safe air environment during their workday.