What Is Crystalline Silica?
Crystalline silica is a simple compound of silicon and oxygen commonly known as silicon dioxide. Silica is everywhere — in quartz stone, concrete, masonry, abrasives and glass. Computer chips are made from silicon, a refined form of silica. And you’ll easily recognize silica in one of its most common forms — sand.
Silica’s Hidden Dangers
For over 75 years, the US government has warned American workers about the health risks associated with crystalline silica. Scientific studies have proven that airborne silica dust, when inhaled, can cause silicosis — a serious and irreversible lung disease. Silica dust has been linked to other serious illnesses, including cancer, and is known to aggravate other conditions including tuberculosis, emphysema and chronic obstructive pulmonary disease (COPD).
It’s Only Dangerous When Inhaled — but Then It Can Be Deadly
Silica has been mined for centuries and has been recognized as an occupational health hazard for decades. Like asbestos, silica is benign in its undisturbed state but becomes a health hazard when the solid crystals are reduced to tiny dust particles that can be easily inhaled. Whenever materials containing crystalline silica — masonry, brick, stone, concrete, glass — are sawn, drilled, chipped, or crushed, silica dust is created and released. Silica sand is especially problematic because it’s grainy and dusty even in its natural state.
Silica: Essential and Unavoidable in More Than 25 Industries
It’s estimated that more than 2.2 million American workers are exposed to silica on the job. You can’t drill a well or dig a mine without encountering silica and it’s essential in the manufacture of fine china, glass and ceramics. Common building materials like concrete, cement, sandpaper, sandstone, granite and limestone also contain silica. Silica is used as filler in a variety of plastic materials, rubber and house paint as well as sheet rock, batteries, optics, refractory materials, iron and steel. Massive amounts of silica are used in many industries. Here’s an example: mountains of sand are quarried, transported, washed, refined, separated and stored to make the silicon used in the manufacture of photovoltaic (PV) cells for the solar energy industry.
Quarry Workers Face Increased Risk of Death
The National Center for Biotechnology Information (NCBI), an organization that “advances science and health by providing access to biomedical and genomic information,” points out that the silica dust released in quarry processes is a serious problem. In a recent study NCBI discovered that quarry workers who are exposed to silica at today’s current limit have a 93% increased risk of death from silicosis and lung cancer and conclude that this limit must be lowered.
Today’s Regs Were Implemented When Richard Nixon Was President
The OSHA safety regs that are intended to keep workers safe from the hazards of silica dust were implemented back in 1971. Since then, scientists have proven silica’s deadly link to serious and often fatal illness, but the safety regulations just haven’t caught up.
OSHA Proposes a New Regulation
The Federal Register, a daily journal of the US government, recently reported that OSHA proposes to amend its existing standard for occupational exposure to respirable crystalline silica because workers exposed to it “face a significant risk to their health at the current permissible exposure limits.”
OSHA’s proposal, “Occupational Exposure to Respirable Crystalline Silica” is still just that — a proposed amendment to earlier regulations. OSHA estimates that these new regulations could save nearly 700 lives a year and prevent 1,600 new cases of silicosis annually.
The proposal, if implemented, would require a lower permissible exposure limit along with establishing preferred methods of controlling exposure, including respiratory protection, medical surveillance, hazard communication and recordkeeping. OSHA also proposes separate regulations for general industry/maritime and construction.
Although OSHA’s proposed control methods are extensive, they’re based on common sense and wouldn’t be difficult or expensive to follow.
- Lower PEL to 50 micrograms of respirable crystalline silica per cubic meter of air (50 μg/m3)
- Require employers to assess employee exposure using air monitoring or objective data
- Require employers to establish regulated areas or create a written access control plan for areas with exposure above the proposed PEL
- Seek public input about appropriate work practices and respiratory protection
- Seek public input on the many questions about the type and quality of medical surveillance available
- Require employers to provide hazard information to employees in accordance with OSHA’s Hazard Communication standard
- Require recordkeeping for air monitoring data, objective data, and medical surveillance records