Most provisions of the Respirable Crystalline Silica standard for general industry and maritime, 29 CFR § 1910.1053, became enforceable on June 23, 2018. The standard establishes a new 8-hour time-weighted average (TWA) permissible exposure limit (PEL) of 50 µg/m3, an action level (AL) of 25 µg/m3, and associated ancillary requirements.

Exposures to respirable crystalline silica dust during construction activities can cause serious respiratory disease. Each year more than 300 U.S. workers die from silicosis and thousands more are diagnosed with the lung disease. It is frequently misdiagnosed, so actual numbers may be higher.

Silica is a natural mineral that comes in several forms, some more hazardous than others. Typically, it’s the crystalline forms that are of greatest concern.

Silica can be present in large quantities in certain types of rocks and sand. Construction materials made from these natural ingredients then become the source of exposure associated with several of the construction trades, such as tile roofs, masonry and concrete finishing or re-finishing.

The following are some examples of work operations where the Cal/OSHA 8-hour average PEL of 0.1 mg/m3 for crystalline silica can be exceeded. There may very well be other operations you do, not listed here, that can also produce excessive exposure levels, such as dry grinding on granite countertops.

  • Tuck point grinding
  • Surface grinder
  • Rock drill
  • Broom or shovel
  • Jackhammer/chipping gun
  • Hand-held masonry saw
  • Road mill
  • Backhoe, excavator, bulldozer
  • Walk-behind concrete saw
  • Mixing concrete, grout, etc
  • Bobcat

Breathing too much dust containing the crystalline forms of silica particles small enough to enter the deep parts of the lung can cause “silicosis”, which is a scarring of the lung tissues, cancer and other forms of lung disease, including an increased risk of getting tuberculosis.

It usually takes several years before you know that you have a problem. Higher exposures can produce health problems much sooner. At first, there can be no symptoms of disease, and then shortness of breath, fatigue, severe cough and chest pain can develop later on. Short of a lung transplant, silicosis can not be reversed, so best to minimize exposures now to prevent disability later in life.

Best Ways for Employees to Protect Themselves:

Knowledge, equipment and work practices: Ask your employer if your work can produce excessive silica dust exposure, and what control measures are to be used. Where possible, work with products that don’t contain silica. For example, there are a variety of materials such as glass beads, pumice, sawdust, steel grit, shot, and walnut shells that are available as substitutes for sandblasting operations.

Understand the hazards and take the appropriate preventative measures. Minimize dust getting into the air you breath: Use equipment designed to cut, saw and grind wet or use ventilation that captures the dust as it is created. Proper use and preventive maintenance is critical.

Don’t smoke tobacco products. Never use compressed air to clean dust off equipment, surfaces or your clothes. Where safely feasible, use water or a HEPA vacuum. Consider using disposable or reusable clothing that stays at the work site. Minimize dust generation when working with or around silica-containing materials. Handle and dispose of waste materials without generating airborne dust. Use a HEPA vacuum, squeegee instead of broom, or sweeping compound, in that order.