Reducing Silica Exposure Amongst Stone Countertop Workers

Silica is threatening the health of many countertop workers—here’s what you can do to reduce their risk.

• By Carly Engels Johnston, Erik Johnson
• May 01, 2020

Home renovation is a trend that continues to gain momentum throughout the United States. Likewise, new hotels, offices, and other structures are being built at a rapid pace. Throughout all these projects, many builders are often choosing to install stone countertops, whether marble, granite or engineered stone that includes quartz and other components. But there is a significant potential hazard facing stone countertop production facilities that is clouding the health and safety of the workers tasked with producing these slabs: silica.

What is Respirable Crystalline Silica?

Crystalline silica is a common mineral that is found in materials such as stone, artificial stone and sand. When workers cut, grind, mix, demolish, polish or drill materials used in stone and engineered stone countertop fabrication that contain crystalline silica, they can be exposed to very small silica dust particles. These respirable crystalline silica particles are able to travel deep into workers’ lungs and are associated with adverse health effects, including silicosis which is an incurable and sometimes deadly lung disease.

Silicosis and Stone and Engineered Stone Countertop Production

Finding cases of silicosis in the countertop industry is something relatively new in the United States that has recently been reported on in the media as well as by the U.S. Centers for Disease Control and Prevention (CDC) and the federal Occupational Health and Safety Administration (OSHA).¹ The CDC and U.S. OSHA estimate that over two million American workers are already exposed to silica in construction.²

These government agencies and media outlets have helped bring to light the hazards of stone and engineered stone countertop production resulting in silica exposure, especially when the process of dry-cutting is used instead of wet-cutting.³ As these news stories and the statistics show, reports of silicosis, including fatalities, have increased among stone countertop workers.⁴

As the demand for these stone and engineered stone countertop products has risen, so has the need for more workers and more production. Moreover, not only does natural granite contain silica, but engineered stone contains about twice as much quartz. Crystalline silica content in countertop materials ranges from between 45 percent in granite to 90 percent in engineered stone. Workers utilizing such materials may be exposed to these small silica particles when cutting, grinding, chipping, drilling and polishing stone and engineered stone products; handling ground quartz; or cleaning up afterwards. Use of hand tools at the shop or job site can lead to some of the highest exposure levels.

Breathing in airborne crystalline silica has not only been associated with silicosis (inflammation and scarring of lungs that permanently reduces ability to take in oxygen) but also lung cancer, chronic obstructive pulmonary disease (COPD), decreased immune system and kidney disease.

Also, there are countertop production facilities throughout the United States that include every type of facility from small shops to large manufacturing plants. Employers should take steps to protect their workers from silica exposure. No matter what the size of the facility, workers should carefully review the following recommendations and implement the U.S. OSHA silica standard requirements to help protect their workers.

U.S. OSHA Silica Standards

In 2016, U.S. OSHA published standards for occupational exposure to silica in both construction (29 CFR 1926.1153) and general industry (29 CFR 1910.1053). These standards, along with frequently asked questions, small business compliance guides, and training materials may be found at www.osha.gov/dsg/topics/silicacrystalline.

Highlights of these standards include:

1) Lower exposure limit of 0.05 mg/m3 for respirable crystalline silica

2) Exposure monitoring

3) Engineering controls such as wet suppression, dust collection, and ventilation

4) Housekeeping to keep dust levels down

5) Limiting access to, or duration in, hazardous area

6) Respiratory protection

7) Written exposure control plan (WECP)

8) Designated competent person (construction only)

9) Medical surveillance to identify silicosis in exposed workers

10) Training including hazards of respirable silica and ensure workers can demonstrate their knowledge

11) Record keeping

Reducing Exposure: Engineering Controls and Respiratory PPE

If countertop-making businesses don't follow applicable worker protection regulations, cutting these slabs to fit customers' kitchens and other uses can release lung-damaging silica that can severely injure workers as well as open these fabrication companies up to violations, fines and other problems. Remember, silicosis is preventable, but not curable.

So, what should safety managers and owners of these companies do to protect their workforce?

First, assess if employee exposures to respirable crystalline silica are at or above the levels prescribed by OSHA by conducting air monitoring and exposure assessments. Next, establish and implement a written exposure control plan (WECP) that identifies tasks that involve exposure, and methods used to protect workers in accordance with the U.S. OSHA silica standards.

Engineering controls such as using tools that include water feeds and high-efficiency particulate air vacuums (HEPA) can help to reduce dust. Other engineering controls may include:

• Isolating high dust activities such as angle grinding or cutting
• Installing local exhaust ventilation systems next to the dust generation point
• Utilizing wet sweeping or HEPA vacuums to clean up instead of dry sweeping or compressed air

If these methods are not adequate or while they are being implemented, respirators may help further reduce exposure to and inhalation of silica dust. Depending on airborne respirable silica levels, respirator options range from disposable or reusable half facepiece particulate respirators to powered or supplied air respirators.

When respirators are used, OSHA requires a written respiratory protection program that includes, but is not limited to, proper exposure assessment, proper respirator selection, requirements for respirator maintenance use and care, along with fit testing, training and a medical evaluation to ensure that the worker can safely wear the assigned respirator. This respirator protection program must have an administrator and be evaluated to ensure effectiveness. Employers and employees may also want to consider eye protection, gloves and protective coveralls depending on the level of exposure.

Employers must also train workers on the hazards of silica, ways to limit exposure and the WECP. Workers should be able to demonstrate that they are aware of these risks and precautionary steps they should be taking to help protect themselves. You should keep records of all this, including completed trainings, each location’s WECP, exposure measurements, objective data, respiratory program forms and medical exams.

Forming a countertop and a way to protect the workers who make them go hand-in-hand. Silica exposure is preventable when employers take the right steps to conform to regulatory standards. Consult with a reputable PPE provider or manufacturer for help selecting the right respiratory protection for your workers.

REFERENCES

¹ Greenfieldboyce, N. There's No Good Dust': What Happens After Quartz Countertops Leave The Factory. NPR. December 2, 2019: https://www.npr.org/sections/health-shots/2019/12/02/782958005/there-s-no-good-dust-what-happens-after-quartz-countertops-leave-the-factory

² https://www.osha.gov/dsg/topics/silicacrystalline/

³ Rose C, Heinzerling A, Patel K, et al. Severe Silicosis in Engineered Stone Fabrication Workers — California, Colorado, Texas, and Washington, 2017–2019. MMWR Morb Mortal Wkly Rep 2019;68: 813–818. DOI: http://dx.doi.org/10.15585/mmwr.mm6838a1

⁴ Greenfieldboyce, N. A New Safety Programs Takes on Silica Dust Amid a Possible Crisis. NPR. December 21, 2019: https://www.npr.org/sections/health-shots/2019/12/21/790298648/a-new-safety-program-takes-on-silica-dust-amid-a-possible-crisis

⁵ Hazard Alert: Worker Exposure to Silica during Countertop Manufacturing, Finishing and Installation. DHHS (NIOSH) Publication Number 2015-106. OSHA–HA-3668-2015. https://www.osha.gov/Publications/OSHA3768.pdf

This article originally appeared in the May 2020 issue of Occupational Health & Safety.