Controlling dust at the source is the best way to protect employees from airborne crystalline silica dest. For example, Husqvarna’s FS 6600 flat saw uses water to minimize dust.
Husqvarna Construction Products Controlling dust at the source is the best way to protect employees from airborne crystalline silica dest. For example, Husqvarna’s FS 6600 flat saw uses water to minimize dust.

Contractors want to protect their workers for a variety of reasons, starting simply with it’s the right thing to do. Keeping your employees and your clients safe is also your legal responsibility. This is why it’s important to know and understand the following regulations, the first of which may have a big impact on your future concrete sawing, cutting, and polishing work.

Crystalline silica rule

We have long been aware that silica dust is bad for workers’ health—inhaling silica can cause silicosis, where the dust creates scar tissue in the lungs, reducing breathing capacity and increasing susceptibility to lung infections. The dust that’s of most concern to contractors working with concrete surfaces is respirable (small enough to be breathed into the lungs and invisible to the human eye). Because crystalline silica is quartz, and nearly all concrete contains quartz from sand in the mix, respirable silica dust is generated by sawing, drilling, or grinding concrete.

Most contractors today provide some sort of dust-control measures, from sawing wet to vacuum systems to ventilators. However, the Occupational Safety and Health Administration (OSHA) has recently proposed a new rule that could present a burden to anyone who cuts concrete.

OSHA proposes reduced PELs

OSHA currently enforces permissible exposure limits (PELs) of 100 micrograms per cubic meter (100 µg/m3), averaged over an eight-hour day, for airborne crystalline silica in general industry, construction, and shipyards. These standards are dangerously out of date, says David Michaels, assistant secretary of labor for OSHA: “The current standards are more than 40 years old, and they are based on research from the 1960s and even earlier.”

According to Michaels, more recent studies have found increased risk of lung cancer among silica-exposed workers. Additionally, federal agencies such as the National Institute for Occupational Safety and Health (NIOSH) have identified respirable silica as cancer-causing.

The proposed rulemaking aims to bring “protection into the 21st century” by halving the exposure limit to 50 micrograms per cubic meter (50 µg/m3), which is what NIOSH recommended back in 1974. It includes two separate standards—one for general industry and maritime employment, and one for construction. The construction standard would require employers to:

  • Measure the amount of silica that workers are exposed to, if you suspect that it may be at or above 25 µg/m3, averaged over an eight-hour day. (Author’s note: If you can see dust in the air, then the level is too high to be breathing it. Although respirable dust is too small to see, it is nearly always accompanied by larger visible dust.)
  • Limit workers’ access to areas where they could be exposed above the PEL.
  • Use dust controls to protect workers from silica exposures above the PEL. (The best, and OSHA-preferred, method is to prevent the dust from getting into the air in the first place. This means vacuum systems or wet-cutting or grinding methods.)
  • Provide respirators to workers when dust controls cannot limit exposures to the PEL. (Paper dust masks cannot filter out respirable crystalline silica dust.)
  • Offer medical exams, including chest X-rays and lung function tests, every three years for workers exposed above the PEL for 30 or more days a year.
  • Train workers on work operations that result in silica exposure and ways to limit exposure.
  • Keep records of workers’ silica exposure and medical exams.

OSHA estimates that the proposed rule will save nearly 700 lives and prevent 1600 new cases of silicosis per year, once the full effects of the rule are realized.