Visible and Respirable Dust
Visible dust contains large particles that are easy to see. The tiny, respirable-sized particles (those that can get into the deep lung) containing silica pose the greatest hazard and are not visible.
This pile of silica-containing waste contains visible and respirable silica.
Most dust-generating construction activities produce a mixture of visible and respirable particles.
- Use visible dust as a general guide for improving dust suppression efforts. If you see visible dust being generated, emissions of respirable silica are probably too high.
- Measures that control tool-generated dust at the source usually reduce all types of particle emissions, including respirable particles.
- Do not rely only on visible dust to assess the extent of the silica hazard. There may be airborne respirable dust present that is not visible to the naked eye.
Knowledge Check Choose the best answer for the question.
9-3. What type of silica dust poses the greatest hazard to workers?
You forgot to answer the question!