Working Safely with Crystalline Silica

What Contractors Need to Know about Safety and New Rules

Many workers are often exposed to crystalline silica in the construction industry and the U.S. Department of Labor is strictly enforcing the reduction of silica dust they can be exposed to over a period of time.

What is crystalline silica?

It’s a basic component of sand, granite, soil, and many other minerals. The most common form of crystalline silica is quartz. The other forms of crystalline silica are tridymite and cristobalite. All of these three forms can be broken down into respirable particles that result from drilling, cutting, grinding, and can lead to many diseases that have debilitating effects on the lungs.

Crystalline silica hazards

According to the Occupational Safety and Health Administration (OSHA), silica exposure is a serious threat to nearly two million U.S. workers. More than 100,000 workers have high risk jobs such as abrasive blasting, foundry work, stonecutting, rock drilling, quarry work, and tunneling. Workers who are exposed to respirable crystalline silica can develop silicosis, lung cancer, respiratory diseases, and kidney disease.

How is exposure being reduced?  

OSHA recently released a new silica standard for construction that went into effect on Sept. 23, 2017. Contractors must meet a stricter standard for how much of silica dust workers inhale as well as employers of tradespeople working around such exposure.

The new standard specifies what services employers must make available to workers who are exposed to high levels of silica dust and the training required of those who are at risk.

The previous silica standard required that dust particles, which are 100 times smaller than sand granules, be limited to 250 micrograms per cubic meter of air over an average of eight hours – the hours of a typical work shift. Now, the new standard reduces that to 50 micrograms over the same period.

If contractors do not comply with the new standard, they are subject to maximum fines of:

• $12,675 for a serious or other-than-serious violation.
• $12,675 per day past the abatement date for a failure-to-abate violation.
• $126,749 for a repeated or willful violation.

In addition to the exposure limits, the new rules also require contractors to:

• Establish and develop a written silica exposure control plan.
• Designate someone to implement the plan.
• Adjust housekeeping practices to maximize control of silica dust.
• Provide medical exams every three years to employees who are exposed to silica, to the point of having to wear a respirator for 30 days or more each year. The exams must include lung-function tests and chest X-rays.
• Train workers on how to limit exposure to silica.
• Keep records of workers’ silica exposure and all medical treatment.

Silica Dust Control Methods

There’s two main methods used to control silica dust while operating a handheld saw:

• Wet cutting
• Vacuum dust collection systems

A good way to reduce the amount of silica dust that becomes airborne is through wet cutting. This controls the exposure at its source. Water can be supplied to the saws by either a pressurized container or by a constant water source such as a hose connected to a faucet.

There’s also vacuum dust collection systems (VDCSs) but may not reliably keep exposure below OSHA’s exposure limit. These work best when workers are properly trained and use good work practices.

For more detailed information on how to control silica exposure, visit OSHA’s website.