Chasing concrete and raking mortar can produce very high levels of silica-containing dust. Effective control is necessary because this work is high risk. This page provides information on how to control this risk and why it needs to be controlled. When uncontrolled, chasing concrete and raking mortar quickly produce very high levels of silica-containing dust, as is shown in a graph displayed in a video that is available on the page. The graph shows a dramatic drop in the amount of silica-containing dust produced when using extraction.
respirable crystalline silica