The new safety rules aim to protect engineered stone manufacturing workers from a progressive and potentially deadly lung disease caused by crystalline silica dust exposure.
On December 13, the California Occupational Safety and Health Standards Board voted to adopt temporary emergency rules to address the rising number of silicosis cases among workers in the artificial stone countertop industry.
The move follows Australia's recent ban on engineered stone, which will take effect next year.
Silicosis is an incurable lung disease caused by inhaling crystalline silica, a component of artificial stone. Exposure to silica dust occurs when stone fabricators cut or grind the material during the manufacturing process. Inhaled silica causes lung scarring, leading to persistent cough, shortness of breath, and difficulty breathing. The disease may progress rapidly and can result in death.
Consumer demand for artificial stone has risen sharply, and it is now the most popular countertop product used in the United States, according to the board's Finding of Emergency report. And this rising demand has likely fueled an increase in silicosis cases among engineered stone workers.
For example, a study published on July 24 in JAMA Internal Medicine identified 52 cases of silicosis among California engineered-stone workers. Most were Latino immigrants, and a majority were diagnosed between 2019 and 2022. The researchers reported that 20 individuals had advanced disease at diagnosis, and 10 died.
However, the board's report indicates that California's total number of silicosis cases increased by 79% from July to November of this year. Moreover, these cases occurred at a young age and have been particularly aggressive, with rapid disease progression, accelerated decline in lung function, and a high mortality rate.
Currently, approximately 4,040 people work in stone fabrication shops across California. The report indicates that 12% to 21% of artificial stone fabricators eventually develop silicosis with a fatality rate of 19%.
Therefore, state regulators estimate that between 500 and 850 cases of silicosis will occur among these employees, and between 90 and 160 will likely die if officials fail to take protective action.
How will California's new rules protect workers?
The emergency rules adopted by the Occupational Safety and Health Standards Board are expected to take effect by the end of December if they are found legally valid by a state regulatory review office. The new standard will modify the existing silica standards outlined in the California Code of Regulations (CCR) title 8, section 5204.
The standards will also address engineering controls, safe work practices, respiratory protection, housekeeping, signage, training, and reporting in manufacturing facilities where workers handle artificial and natural stone that contains silica.
In addition, the new rules will close loopholes in section 5204 that employers previously used to avoid complying with regulations and make enforcement by the Occupational Safety and Health Administration (OSHA) more efficient.
Over the next 10 years, the emergency temporary standard is expected to cost artificial stone manufacturing businesses $66 million. Still, the board's report said the benefits achieved over the same timeframe could reach $603 million.
- California Department of Industrial Relations: Occupational Safety and Health Standards Board. Finding of Emergency Section 5204, Occupational Exposures to Respirable Crystalline Silica Business Meeting: December 14, 2023.
- JAMA Internal Medicine. Silicosis Among Immigrant Engineered Stone (Quartz) Countertop Fabrication Workers in California.
- American Lung Association. Silicosis.