Cal/OSHA Issues Emergency Temporary Standard on Respirable Crystalline Silica

The Occupational Safety and Health Standards Board of the California Division of Occupational Safety and Health (Cal/OSHA) has approved an emergency temporary standard to protect workers from silicosis, an incurable, potentially fatal lung disease. All California workers exposed to respirable crystalline silica other than those employed in construction or agricultural operations are covered by the emergency temporary standard, which went into effect Dec. 29, 2023. The emergency temporary standard requires employers to implement protections for workers engaged in high-exposure “trigger” tasks such as cutting, grinding, polishing, and cleanup of artificial stone containing more than 0.1 percent crystalline silica and natural stone containing more than 10 percent crystalline silica.

The California Department of Public Health (CDPH) has identified 95 cases of workers who developed silicosis since 2019, including 10 workers who have died of the disease, according to a press release issued by the state’s Department of Industrial Relations (DIR). Those who cut artificial stone, a material that can contain 93 percent or greater crystalline silica, are at most risk for developing silicosis.

Under the emergency temporary standard, employers must implement controls such as wetting stone to suppress dust, monitoring respirable crystalline silica levels in the air, and requiring the use of powered air-purifying respirators. Employers must also fulfill communication requirements such as providing information and training appropriate to employees’ language and literacy needs, conducting exposure assessments for silica at least every 12 months, and reporting any employees with confirmed silicosis or lung cancer to Cal/OSHA and CDPH.

Further information about the emergency temporary standard may be found in DIR’s press release and in an executive summary issued by Cal/OSHA (PDF). Additional resources on silica may be found on DIR’s website.