Cutting concrete and masonry generates respirable crystalline silica dust. What is the BEST engineering control to reduce worker exposure?

Giải thích

The preferred controls for silica are engineering controls that capture or suppress dust at the source, wet cutting with water or a tool-mounted vacuum with HEPA filtration, supplemented by respirators when needed. Option a reflects this hierarchy. Breath-holding (b) and cutting faster (c) do nothing to reduce airborne silica, and a single paper mask alone (d) is inadequate for crystalline silica.