Crystalline silica

Quartz is the most common form of crystalline silica. Quartz is found in brick, mortar, plain pavement, concrete, rock and granite. Activities such as demolishing, crushing, drilling, sawing, grinding, sanding and sweeping materials containing crystalline silica expose workers to its dust.

Exposure to crystalline silica dust can cause respiratory disorders ranging from shortness of breath on exertion to severe respiratory failure, which are symptoms of silicosis. It can also lead to asthma, emphysema, silicosis, lung cancer and death, among others. The employer is responsible for implementing measures to control crystalline silica emissions at source. Where necessary, they must also put a respiratory protection program in place and train workers on the wearing, maintenance and storage of respiratory protective equipment.

For their part, workers must wear respiratory protective equipment, in addition to having a means of control at source, for zero tolerance activities. Respiratory protective equipment must be as stipulated in the Guide des appareils de protection respiratoire utilisés au Québec. It must be selected, adjusted, used and cared for in accordance with CSA Standard Z94.4-93, “Selection, Use and Care of Respirators”.

Safety rules

Other mandatory preventive measures

Depending on the tasks to be performed, one or more of the following measures must be taken by the employer to control the risks associated with crystalline silica:

• implement measures to ensure that crystalline silica emissions are controlled at source. For example:
  • use wet processes
  • equipment fitted with a source capture system or
  • local ventilation systems
     
  • s. 107 of the RSST
  • s. 2.10.8 of the CSTC
  • s. 51(5) of the LSST
     
• develop and implement a respiratory protection program and train workers on the wearing, care and storage of respiratory protective equipment
   
  • s. 45 of the RSST This section also applies to construction sites.
     
• train and inform workers on the risks associated with exposure to crystalline silica and on the use of means to control silica emissions
   
  • s. 51(9) of the LSST
     
• make sure that the equipment used to prevent the emission of silica dust is in working order and operating optimally during operating hours
   
  • s. 5 of the RSST This section also applies to construction sites.
     
• inspect mechanical ventilation systems at least once a year
   
  • s. 104 of the RSST
     
• ensure proper maintenance of the premises by limiting dust
   
  • s. 17 of the RSST This section also applies to construction sites.
     
• replace silica-containing materials where possible
   
  • s. 39 of the RSST

Protective measures

• Respiratory protective equipment
• Protective clothing