Crystalline silica is a common mineral found in materials like sand, rock, brick, and concrete.
By itself, the mineral silica is generally not a concern. But when workers cut, grind, or drill into materials that contain silica, hazardous dust is released into the air. This can cause serious health effects for workers.
Silica Exposure in the Workplace
Respirable silica dust is created when cutting, sawing, grinding, drilling, or crushing materials such as stone, rock, concrete, brick, and mortar.
Workers in both construction and general industry risk exposure to silica hazards. In fact, according to OSHA, about 2.3 million workers are exposed to silica at work.
Here are some examples of jobs and industries that often deal with silica hazards:
- Abrasive blasting with sand
- Sawing brick or concrete
- Sanding or drilling into concrete walls
- Grinding mortar
- Cutting or crushing stone
- Manufacturing brick, concrete blocks, stone countertops, or ceramic products
Workers who are repeatedly exposed to silica dust hazards face the greatest risk of developing respiratory health issues.
Respiratory Health Effects of Silica
When workers breathe in the hazardous silica dust, it can cause significant damage to their lungs. Some of the respiratory health effects include:
- Lung cancer
- Chronic Obstructive Pulmonary Disease (COPD)
Silicosis is an incurable lung disease that is extremely debilitating and can sometimes be fatal. The National Institute for Occupational Safety and Health (NIOSH) estimates that over 100 workers are still killed annually from this preventable disease.
Silicosis occurs when workers engage in activities that result in exposure to silica dust. Silica crystals travel through their mouth and nose and deep into the lungs.
Unfortunately, the body is unable to defend itself from these tiny, hazardous particulates. The crystals become permanently attached the walls of the lung. This results in the formation of scar tissue, which spreads and weakens the lungs.
As time goes on, so much scar tissue will have formed that the lungs are unable to function properly.
Those who work in construction, mining, and agriculture face the greatest risk of developing silicosis during their lifetime.
(Learn more in Everything You Should Know About Silicosis.)
Lung cancer can also result from exposure to silica dust hazards. Lung cancer occurs when abnormal cells grow into tumors which then affect the ability of your lungs to function properly.
If lung cancer is not detected or treated early, it can spread to other parts of the body.
(Find out How to Reduce the Risk of Occupational Cancer.)
COPD is most commonly found in the form of emphysema and chronic bronchitis. Exposure to respirable crystalline silica increases the chances of workers contracting COPD.
The primary symptom of COPD is shortness of breath. Those who have this disease often face a difficult and painful road ahead. COPD is not usually reversible, and may worsen over time.
Each of these diseases are life-altering and debilitating disorders that affect thousands of workers each year in the United States.
These conditions and the onset of their symptoms often develop over time. For instance, silicosis typically occurs 15 to 20 years after exposure.
That's why preventative measures and early intervention are absolutely crucial.
Protecting Workers from Silica Hazards
It also identifies when dust control, respirators, and other protective measures must be implemented. The standards for training, record-keeping, and frequency of medical exams have been updated as well.
As with most occupational health hazards, following the Hierarchy of Controls is the best way to protect workers.
Whenever possible, try to eliminate or substitute the hazards. If this is not feasible (which is often the case with silica), then implement engineering controls, administrative controls, and provide the proper PPE.
OSHA has identified the following as sufficient engineering control methods:
- Wet methods that apply water at the point where silica dust is made
- Local exhaust ventilation that removes silica dust at or near the point where it is made
- Enclosures that isolate the work process or the worker
Examples of administrative controls include:
- Limiting access to areas where workers could be exposed above the Permissible Exposure Limit
- Establishing and implementing a written exposure control plan that identifies tasks that involve exposure (and lists the methods used to protect workers)
- Restricting housekeeping practices that expose workers to silica, such as use of compressed air without a ventilation system to capture the dust
- Offering medical exams (including chest X-rays and lung function tests) every three years to workers who are exposed at or above the action level for 30 or more days per year
When it comes to Personal Protective Equipment (PPE), NIOSH-Approved respirators are designed to protect workers when all other protective measures fall short.
The bottom line, is that employers must take the steps necessary to ensure workers are not exposed to hazardous quantities of respirable silica dust.