Lung disease from inhaling sand or rock dust is one of the oldest occupational hazards. The health risks of silica were identified as early as 1700. Silicosis, the incurable lung disease caused by inhaling silica dust, causes hundreds of deaths every year. Other health effects include liver and immune system diseases. After studying the research, OSHA concluded that the current silica exposure limits were too high. A new silica exposure limit needed to be set to protect workers.
Some silica exposure still comes from well-known occupations like stone cutting, mining, and drilling. Abrasive blasting with sand is especially dangerous. However, newer industries have created new sources of exposure. One example of this is hydraulic fracturing, or fracking, for oil and gas. Another example is the popularity of natural and manufactured stone countertops. All of these industries must achieve compliance with OSHA’s new silica law to keep workers safe.
HOW DOES SILICA HURT YOU?
Silica is one of the most common elements on earth. It makes up a major part of sand, rocks, and all products made from those things, like concrete.
The major health risks of silica happen when it is inhaled into the lungs. Silica that is small enough to be inhaled is called “respirable crystalline silica” in formal OSHA language. Drilling or grinding creates fine silica dust, and sand is already a form of crystalline silica that can become airborne, especially during blasting or fracking operations.
The biggest concern with silica is a disease called silicosis. The American Lung Association warns about the permanent lung damage that happens with this disease.
Silicosis happens when silica dust damages the lining of the tiny air sacs in the lungs. This injury causes scarring and makes it harder for the air sacs to get oxygen into your body.
Acute silicosis can occur within weeks or months of very heavy exposure. In this case, the lungs respond to the injury by swelling up and filling with fluid. This can be very dangerous and make it very hard to breathe.
Chronic silicosis is the most common kind. The swelling and scarring of the lungs happens over years. Symptoms include coughing, chest pain, and sometimes tiredness and weight loss. The scarring can progress to a condition called progressive massive fibrosis, where the lungs become stiff and full of scar tissue. When the disease is severe, people may need oxygen support to be able to breathe. Silicosis can cause death.
The health risks of silica include other deadly conditions. Silica is a known carcinogen, meaning it causes lung cancer. It also makes you more likely to get lung diseases like emphysema, tuberculosis or bronchitis. NIOSH, the research arm of OSHA, reviewed all of the studies on silica exposure and wrote a detailed report on it.
HOW CAN THE HEALTH RISKS OF SILICA BE CONTROLLED?
OSHA recommends that the first line of defense is replacing silica with safer materials. This isn’t always an option. Replacement products may be expensive or just not available. Silica is common, cheap, and stable, which makes it hard to replace.
The second line of defense, and usually the best option when possible, is using engineering controls. A popular engineering control is a dust collector. A dust collection system removes silica dust from the work area and captures it safely so it can be reused or disposed of. Just venting the dust out of the work area means that it ends up somewhere else, and that can be a problem.
A dust collector filters silica dust from the air. The dust drops into a hopper for safe handling. The air can be returned to the work area. The system can clean a large area and keep an entire facility free of silica dust.
Dust collectors can also be installed on equipment such as sand trucks or conveyors to control silica dust when moving sand around. This is important in fracking applications.
In situations like construction or drilling, the best solution may be a NIOSH-certified respirator. Because respirators are uncomfortable and difficult to fit correctly, they are not the ideal solution. Sometimes, though, they are the only option. If you must wear a respirator to protect you from the health risks of silica, make sure it is NIOSH-certified for the job you’re doing, and make sure it fits correctly.