Concrete cutting and concrete grinding are very dusty jobs in the construction industry, both posing a serious health risk to masons. Masonry blocks, bricks, and concrete slabs contain concentrated amounts of crystalline silica. When these materials are dry-cut they release silica containing dust into the workers’ breathing zone. Regular exposure to this hazardous dust can lead to the development of silicosis, a deadly and incurable lung disease. It is estimated that roughly 250 construction workers die each year due to exposure to dangerously high levels of silica dust.
Masons and construction workers face various levels of exposure to silica dust depending on the task being performed. For instance, there is less potential for overexposure for masons who perform wet tasks such as laying blocks in mortar or wet cutting concrete.
On the other hand, masons who dry cut concrete blocks and slabs regularly face exposures that are up to 10 times OSHA’s defined permissible exposure limit (PEL). Dry cutting tasks increase the likeliness that an employee will develop a lung disease over a period of 10 or more years.
While dry cutting increases the likeliness of developing a lung related illness, the most dangerous task affecting the health of masons is grinding out deteriorated mortar from brick or concrete structures. Exposures from this type of work can exceed 50 times the OSHA PEL and can cause lung diseases to cultivate over a period of several months to 10 years.
Work Practices to Control Silica Dust Production
Several approaches can be taken to help protect construction workers against the dangers of airborne silica dust. Control methods and work practices that reduce dust accumulation in concrete cutting and grinding include:
- Wet Cutting (Water Spraying) – This engineering control helps to eliminate silica dust from ever becoming airborne and is the most efficient method of dust control in concrete cutting and grinding. Saws and grinding equipment should be fitted with a wet-cutting port, or alternatively, a portable water tank or cart can be supplied. Masons should create a plan prior to arriving to the job location to make certain that the resources and manpower required are accessible for successful wet cutting projects.
- HEPA Vacuum & Exhaust Ventilation Systems – When dust cannot be eliminated at the source, industrial vacuums and exhaust ventilation systems are extremely useful tools. These systems can suck up dust as it forms and can be extremely beneficial during jobsite clean-up. Vacuum systems should be equipped with a high efficiency particulate air (HEPA) filter that prevents collected dust from escaping the vacuum system.
- Training – Employees should receive thorough training on the dangers of silica dust. Training should cover prevention and control methods, respiratory protective equipment, as well as cleaning methods when work is completed.
Open, Enclosed, & Confined Spaces: Half vs. Full Faced Respirators
Depending on the layout of the jobsite, masons and construction workers are required to wear respiratory protective equipment (RPE) where preventative work practices and control methods are not effective enough on their own. Respirators should be properly fit tested prior to use and a respiratory protection program should be implemented to guarantee that they are used safely and appropriately. Listed below are the three main types of respirators that can be used depending on the worksite:
- Disposable Dust Respirators – These can be used in areas where exposures are up to 5 times the OSHA PEL. They are often used by masons who block run, build scaffolds, or mix mortar. These masks must be NIOSH approved in order to be deemed safe enough to mitigate exposure. Frequently they are used in open spaces and on jobs where dust accumulation is relatively low.
- Half Face Dust Respirator – Half face respirators are safe for exposures up to 10 times the OSHA PEL. They should include dust cartridges that are cleared regularly. Typically these respirators are used in open spaces, but can also be used for some projects completed in enclosed spaces.
- Full Face Dust Respirator – Finally, full face dust respirators can protect workers from exposures up to 50 times the OSHA PEL. These are required when a mason is tasked with grinding mortar prior to tuck pointing. Typically these are used in enclosed and confined spaces where dust can accumulate quickly and in large quantities.