Crystalline silica is a common mineral found in the earth’s crust. Materials like sand, stone, concrete, and mortar contain crystalline silica. It is also used to make products such as glass, pottery, ceramics, bricks, and artificial stone.
Respirable crystalline silica – very small particles at least 100 times smaller than ordinary sand you might find on beaches and playgrounds – is created when cutting, sawing, grinding, drilling, and crushing stone, rock, concrete, brick, block, and mortar. Activities such as abrasive blasting with sand; sawing brick or concrete; sanding or drilling into concrete walls; grinding mortar; manufacturing brick, concrete blocks, stone countertops, or ceramic products; and cutting or crushing stone result in worker exposures to respirable crystalline silica dust. Industrial sand used in certain operations, such as foundry work and hydraulic fracturing (fracking), is also a source of respirable crystalline silica exposure. About 2.3 million people in the U.S. are exposed to silica at work.
Workers who inhale these very small crystalline silica particles are at increased risk of developing serious silica-related diseases, including:
- Silicosis, an incurable lung disease that can lead to disability and death;
- Lung cancer;
- Chronic obstructive pulmonary disease (COPD); and
- Kidney disease.
To better protect workers exposed to respirable crystalline silica, OSHA has issued two new respirable crystalline silica standards: one for construction, and the other for general industry and maritime. OSHA will begin enforcing most provisions of the standard for construction on September 23, 2017 and this course is in compliance with the training requirements listed in the standard.
- New OSHA Silica Standard
- Background and health effects
- Specified exposure control methods
- Alternative exposure control methods
- Respiratory protection
- Brief overview:
- Written exposure control plan
- Medical surveillance
OSHA – CR 1926.1153(i)(2)
Frequently Asked Questions
What is crystalline silica?
Crystalline silica is a common mineral found in many naturally occurring materials and used in
many industrial products and at construction sites. Materials like sand, concrete, stone and
mortar contain crystalline silica. Crystalline silica is also used to make products such as glass,
pottery, ceramics, bricks, concrete and artificial stone. Industrial sand used in certain operations,
such as foundry work and hydraulic fracturing (fracking), is also a source of crystalline silica
exposure. Amorphous silica, such as silica gel, is not crystalline silica.
How can exposure to crystalline silica affect workers’ health?
Inhaling very small (“respirable”) crystalline silica particles, causes multiple diseases, including
silicosis, an incurable lung disease that can lead to disability and death. Respirable crystalline silica
also causes lung cancer, chronic obstructive pulmonary disease (COPD), and kidney disease.
Who is at risk from exposure to crystalline silica?
Around 2.3 million workers are exposed to crystalline silica on the job. Simply being near sand
or other silica-containing materials is not hazardous. The hazard exists when specific activities
create respirable dust that is released into the air.
Respirable crystalline silica – very small particles typically at least 100 times smaller than
ordinary sand found on beaches or playgrounds – is generated by high-energy operations like
cutting, sawing, grinding, drilling and crushing stone, rock, concrete, brick, block and mortar; or
when using industrial sand. Activities such as abrasive blasting with sand; sawing brick or
concrete; sanding or drilling into concrete walls; grinding mortar; manufacturing brick, concrete
blocks, or ceramic products; and cutting or crushing stone generates respirable dust.
What is the relationship between silica exposure and lung cancer?
There is strong scientific evidence showing that exposure to respirable crystalline silica can
increase a person’s risk of developing lung cancer. The World Health Organization’s International
Agency for Research on Cancer – the leading international voice on cancer causation – and the
National Institutes of Health’s National Toxicology Program have conducted extensive reviews of
the scientific literature and have designated crystalline silica as a known human carcinogen. The
American Cancer Society has adopted the WHO and NIH’s determinations.
More than 50 peer-reviewed epidemiological studies that OSHA evaluated for this rulemaking
have examined the link between silica exposure and lung cancer in at least 10 industries. In
particular, several studies of workers in specific industrial sectors support the link between
exposure to respirable crystalline silica and lung cancer among workers.
How will the crystalline silica rule protect workers’ health?
The new rule requires that employers use engineering controls − such as ventilation and wet
methods for cutting and sawing crystalline silica-containing materials − to reduce workers’
exposure to silica dust. Once the full effects of the rule are realized, OSHA expects it to prevent
600 deaths a year from silica-related diseases – such as silicosis, lung cancer, other respiratory
diseases and kidney disease – and to prevent more than 900 new cases of silicosis each year.
Why is OSHA issuing a new crystalline silica rule?
OSHA’s previous permissible exposure limits (PELs) for silica were outdated, inconsistent and
did not adequately protect worker health. The previous PELs were based on studies from the
1960s and earlier that did not reflect more recent scientific evidence showing that low-level
exposures to silica cause serious health effects, including lung cancer. In the 45 years since the
previous PELs were established, the U.S. National Toxicology Program, the International
Agency for Research on Cancer, and the National Institute for Occupational Safety and Health
have all identified respirable crystalline silica as a human carcinogen. Previous construction and
shipyard PELs were based on an old method of measuring worker exposures to silica that is not
used today. Those previous limits are inconsistent, allowing permissible levels for construction
and shipyards to be more than twice as high as levels in general industry. The revised rule will
reduce the risk of disease among workers who inhale respirable crystalline silica and provide the
same protection for all workers covered.