In March 2019, the Texas Department of State Health Services (DSHS) received a report of an apparent cluster of multiple cases of silicosis among workers associated with occupational silica dust exposures that occurred during the manufacture, finishing and installation of stone countertops. DSHS is currently investigating these cases. There are no reported silica exposures to consumers from countertops in their homes.
Silicosis is an incurable, disabling, and often-fatal lung disease caused by inhalation of very fine particles of crystalline silica dust over a long period of time, which primarily occurs in workplace settings.
Occupational silicosis among workers in the engineered stone countertop industry is a rising concern in the world. The first case associated with engineered stone countertop fabrication in the United States was reported in Texas in 2014. Workers may be repeatedly exposed to dangerous levels of respirable silica dust when grinding, cutting, routing, drilling, or polishing engineered stone, granite and other stone materials containing crystalline silica during the fabrication process.
The United States Occupational Safety and Health Administration (OSHA) has set a permissible exposure limit (PEL) of 50 µg/m3, averaged over an 8-hour work day, for respirable crystalline silica exposure among workers in fabrication shops and other construction job sites (5,6).
To prevent occupational exposure to silica dust, guidelines require the following:
- Conduct air monitoring to identify the amount of silica dust workers are exposed to, and continue to monitor air levels to make sure the exposure level is below the PEL.
- When possible, eliminate job tasks that can expose workers to silica dust above the PEL.
- Reduce exposure by using dust control methods or engineering controls such as wet methods for cutting or grinding, local exhaust ventilation, wet sweeping, or high efficiency particulate (HEPA)-filtered vacuuming.
- Use administrative controls and safe work practices such as a written exposure control plan and a designated competent person to implement it, and limit access to areas with exposure above the PEL.
- Provide workers with Personal Protective Equipment (PPE) such as respirators and washable clothing when exposure control does not sufficiently reduce the amount of airborne silica dust.
- Train all employees at the worksite on the health effects of silica exposure, workplace tasks that can expose them to silica dust, and how to control or prevent exposures.
- Offer medical screenings to all who may be exposed to silica dust as per OSHA standards (5,6). Keep records of workers’ exposure to silica and medical screening results.
- Participate in trainings on silica exposure control and prevention including use of PPE.
- Follow procedures and protocols to safely work around silica and reduce or prevent exposures.
- Report any possible silica exposure to the employer, supervisor, or health care provider.
More information about crystalline silica in the countertop industry can be found at OSHA’s website.