What is silica and why is it hazardous?

By Jessica Barrett | Last updated: September 20, 2018
Presented by AD Safety Network

A natural mineral found in the Earth, the most common form of silica is quartz. It’s a widely used industrial material and is generally a component in sand, stone, rock, concrete, brick, block, and mortar.

While silica isn’t hazardous when fully contained inside these materials, the dust poses a significant risk to workers. Crystalline silica is produced when workers cut, saw, drill, and crush products made of concrete, brick, ceramic tiles, rock, and stone. Tiny particles of silica dust—known as respirable particles—are inhaled and penetrate the lungs, where they can cause disabling and even deadly illnesses (know what your workers are breathing, read Indoor Air Quality: The Invisible Hazard in Every Workplace).

Hazards of Crystalline Silica

Silica inhalation is a serious hazard and should be treated as such in workplaces around the country. A known carcinogen, it can cause lung cancer and kidney disease, as well as other respiratory illnesses. One of the most common illnesses associated with inhalation of silica dust is silicosis, a debilitating and incurable disease that causes scar tissue to form in the lungs, hindering their ability to take in oxygen.

There are three types of silicosis to be aware of, the most common of which is chronic silicosis. This illness occurs after low to moderate exposure over the long-term (15-20 years). Symptoms may start slowly with shortness of breath while exercising, but they gradually worsen to include fatigue, extreme shortness of breath, chest pain, and respiratory failure.

Workers exposed to high concentrations of crystalline silica for 5-10 years may develop accelerated silicosis, with symptoms that include shortness of breath, weakness, and weight loss.

Acute silicosis is perhaps the most severe form, occurring from 2 months to 2 years after exposure to extremely high silica concentrations. Workers suff

ering from acute silicosis generally experience disabling shortness of breath, weakness, and weight loss, which often proves fatal.

Who It Affects

According to OSHA estimates, nearly 90 percent of workers who are exposed to silica work in the construction industry. Particularly high-risk activities include abrasive blasting with sand to remove paint and rust from structures like bridges. Other risky activities include:

  • Jack hammering
  • Rock/well drilling
  • Concrete mixing
  • Concrete drilling
  • Brick/concrete block cutting and sawing
  • Tuck pointing
  • Tunneling operations

Crystalline silica isn’t just a hazard for construction workers, though. Other industries and operations at risk for exposure include:

  • Glass and pottery products
  • Structural clay products
  • Concrete products and ready-mix concrete
  • Foundries
  • Dental laboratories
  • Paintings and coatings
  • Jewelry production
  • Refractory products, installation, and repair
  • Cut stone and stone products
  • Railroad track maintenance
  • Hydraulic fracturing for gas and oil
  • Abrasive blasting in construction, maritime work, and general industry


While crystalline silica can be absolutely detrimental to worker health, there are a number of things employers and workers alike can do to manage the risks (choose the proper protection by learning 6 Factors to Consider When Choosing a Respiratory Protection Device). I can’t emphasize enough the importance of fully adhering to OSHA’s new standards. By limiting worker exposure, using engineering controls and respirators, and providing comprehensive worker training, employers can protect themselves from hefty non-compliance fines and create a safer working environment for their employees.

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Written by Jessica Barrett

Jessica Barrett

Jessica is a freelance writer and editor from Toronto, Canada. She specializes in creating content for nonprofits and has written for organizations working in human rights, conservation, education, and health care. She loves traveling and food, speaks Spanish, and has two dogs, one of whom she rescued while living in Mexico.

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