Silica

Silica is found in many materials common on construction sites, including sand, concrete, rock, mortar, and brick. When workers cut, grind, abrasive blast, jackhammer or perform other tasks that disturb these materials, dust containing crystalline silica can released into the air. Workers who inhale this dust are at risk. Silica can cause serious, sometimes fatal illnesses including a lung disease called silicosis, lung cancer, and chronic obstructive pulmonary disease (COPD).   
 

How does silica inhalation cause harm to the lungs?

Silicosis can develop within a few weeks to even decades after exposure.  When people breathe silica dust, they inhale tiny particles of the mineral silica.  This silica dust can cause fluid buildup and scar tissue in the lungs that cuts down your ability to breathe

The Hawks Nest Tunnel disaster was a large scale incident of occupational silicosis as the result of construction.  Workers found the mineral silica and were asked to mine it. The workers were not provided with protective masks and many workers developed silicosis.  A large number of workers eventually died, in some cases as quickly as within a year

How to Protect from the Hazards of Silica Dust

  • Use vacuums or water to reduce or eliminate the dust at the source, before it becomes airborne.  When these controls are not enough, use respiratory protection. Routinely maintain dust control systems to keep them in good working order.
  • Do not use sand or other substances containing more than 1% crystalline silica as abrasive blasting materials.  Substitute less hazardous materials.
  • Wear disposable or washable work clothes and shower if facilities are available.
  • Vacuum the dust from your clothes and change into clean clothing before leaving the work site. Do not bring dust home.
  • Do not brush or blow off the dust.
  • Do not eat, drink, or smoke in areas where silica dust is present.  Wash your hands and face outside of dusty areas before performing any of these activities.

Best Practice

  • The best way to protect all workers is to use engineering or work practice controls. If water or other methods cannot be used, then as a last resort, the use of respirators can protect the worker from breathing the silica dust.
  • Rule-of–thumb: if dust containing silica is visible in the air, it is almost always over the permissible limit.
  • Washington State requires that water or exhaust ventilation always be used on masonry saws.


Presenter tips

  • Pre-read the Toolbox Talk. Your comfort level and confidence will be higher if you know your topic.
  • Discuss related tasks, work areas or events that make the Toolbox Talk relevant to your job site.
  • Involve the workers by asking questions and input that drives discussion.

Questions for Discussion

  • Do we have any young workers on this site?
  • In what ways can we reduce injuries in our young workers?