When silica-containing products are manipulated in some way to generate dust, fine crystalline particles are released into the air. Respirable indicates that the silica particles are small enough (less than 10 µm) to reach deep into the alveolar region in the lungs.
When silica particles are inhaled, they can deposit into the alveolar region of the lungs, where scar tissue forms around them leading to significant damage to lung tissue. The resulting, often fatal, disease is called silicosis.
Chronic silicosis is most common and progresses slowly after years of exposure. Silicosis can also occur acutely after exposure to high concentrations. Symptoms can include shortness of breath, cough, fever, weakness, and eventually lead to respiratory failure.
Silicosis is progressive and irreversible. Even if the exposure ceases, the disease continues to progress.
More information on silicosis at CCOHS: Silicosis
Exposure to respirable crystalline silica puts workers at risk for developing other serious diseases including:
Workers who manipulate silica containing materials, such as sand, rock, gravel, concrete, brick, stone, mortar, granite, glass, or ceramics. Dust generating activities such as moving, grinding, cutting, sandblasting, drilling, crushing, mining, or demolition create a risk to the worker. Working with engineered stone products can be particularly hazardous due to the high silica content of the material.
Development of silicosis can be influenced by:
Source: CCOHS: Silicosis
New Brunswick’s occupational exposure limit for Silica is 0.025 mg/m3. Employers must ensure the exposure of an employee at no time exceeds the occupational exposure limit and must implement and maintain appropriate controls. The Silica Control Tool helps employers in select and establish appropriate controls.
Exposure to respirable silica can be prevented with multiple levels of control. Ideally, processes that create respirable silica would be excluded or replaced if possible. Physical barriers can be very effective as well as wetting of materials, local exhaust ventilation, dust-collecting systems, and finally personal protective equipment (PPE) such as respirators.
The Silica Control Tool can assist employers in establishing appropriate controls.
The occupational exposure limit has been established for respirable silica at 0.025 mg/m3. But what does that mean and how can you judge if the dust generated during a given work task will exceed the limit without elaborate and lengthy testing? The Silica Control Tool can help.
The Silica Control Tool will generate an Exposure Control Plan describing the anticipated exposure, chosen control options, and resulting level of respiratory protection required (if any). This plan can be used to communicate the controls and requirements to the workers performing the task, train workers and raise awareness. The Exposure Control Plan can be used by employers to demonstrate compliance to WorkSafeNB Health and Safety Officers. The Officers can use the plan to verify that they are followed as described in the plan, the selected control options are in place and effective, and the level of respiratory protection (if any) used by workers is adequate.
