Silica

Safe Work Practices

What to know

Prevent respirable crystalline silica exposures and control dust when working around materials that contain crystalline silica such as concrete, mortar, granite, and artificial stone. Follow safe work practices and use engineering controls for equipment or processes to protect workers from health risks.

Stone cutting using water method.

Exposure prevention

Follow dust control methods found in:

Steps to avoid silica exposure

  • Ensure that all engineering controls are working properly before using.
  • Use wet methods that apply water to dusty areas.
  • Use local exhaust ventilation where work is dusty.
  • Use enclosures, when available, to isolate work processes.
  • Consider combining water and ventilation controls.
  • Replace water and air filters when needed or per manufacturer's instructions.
  • Avoid dry sweeping or using compressed air during housekeeping procedures.
Water spraying method being used to cut a stone block.
Using water spraying methods to cut stone can prevent dust exposure.

Controlling dust levels can be accomplished by implementing effective engineering controls such as:

  • Local exhaust ventilation to capture dust.
  • Water sprays to suppress dust.

Ensuring worker protection

Occupational Safety and Health Administration

Under the OSHA Respirable Crystalline Silica Rule, employers are responsible for ensuring workers are protected from silica. This includes controlling dust levels below the permissible exposure limit (PEL) of 50 µg/m3 (micrograms of silica per cubic meter of air) as an 8-hour time weighted average. A PEL is the maximum daily concentration that workers can be exposed to for a working lifetime without adverse health effects.

Go to the OSHA Respirable Crystalline Silica webpage for more information on requirements for employers. Employers in states that have an OSHA-approved state plan should follow the applicable standards.

Mine Safety and Health Administration

Miners can be exposed to high levels of respirable silica dust released by the mineral quartz. Exposure can occur during mine operations such as extraction, transport, and processing. To protect exposure to mine workers, the current Mine Safety and Health Administration (MSHA) PEL for respirable quartz is 100 µg/m3, but a proposed rule would lower it to the same PEL that is used by OSHA.

Mining operators can go to the NIOSH Mining webpage for silica-related requirements and safe mining guidance.

Respiratory protection

Employers should provide workers with respiratory protection when dust controls and safe work practices cannot limit exposures below exposure limits.

Medical surveillance programs

Employers should provide workers with medial monitoring or surveillance programs. This includes:

  • Medical exams as required by OSHA.
  • Worker training about the hazards of silica exposure, tasks where exposures can occur, and ways to limit exposure.

Employers should also keep records of worker exposures and medical exams.

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Content Source:
National Institute for Occupational Safety and Health