Eighteen Cases, Two Deaths: The Engineered Stone Silicosis Epidemic and What It Means for Countertop Fabricators
By Paul E. Rosenfeld, M.S., Ph.D., Principal Environmental Chemist, RoseyFields LLC, Santa Monica, California
A modern disease outbreak in an old industry
Countertop fabrication, cutting, grinding, and polishing natural and engineered stone slabs, has existed for decades, but engineered (or artificial) stone, a manufactured quartz composite that can contain more than 90% crystalline silica, has driven a documented modern silicosis outbreak among fabrication workers. Dr. Paul E. Rosenfeld, M.S., Ph.D. of RoseyFields LLC has been retained in California engineered-stone silicosis litigation addressing this exposure pathway directly (Reyes-Cuevas, 2023).
The CDC’s landmark case series
In 2019, the CDC’s Morbidity and Mortality Weekly Report documented 18 cases of silicosis, including the first two fatalities reported in the United States in this industry, among stone fabrication workers in California, Colorado, Texas, and Washington, several with severe progressive disease and associated autoimmune conditions (Rose et al., 2019).
California’s own surveillance confirms a continuing epidemic, not an isolated cluster
A subsequent peer-reviewed study specifically characterizing California’s immigrant engineered-stone countertop fabrication workforce found a substantial and ongoing burden of silicosis in this population, indicating that the 2019 case series identified the beginning of a sustained occupational health crisis rather than a one-time event (Fazio et al., 2023).
Why crystalline silica exposure occurs at such high intensity in this trade
Dry-cutting and grinding of engineered stone generates extremely fine respirable crystalline silica dust, and small fabrication shops historically have not uniformly implemented water suppression, local exhaust ventilation, or respiratory protection, resulting in measured worker exposures that substantially exceed occupational exposure limits in documented industry surveys (Surasi et al., 2022).
The regulatory standard and its 2016 tightening
OSHA’s Respirable Crystalline Silica Standard, effective for the construction industry in 2017 and for general industry in 2018, reduced the permissible exposure limit to 50 micrograms per cubic meter as an 8-hour time-weighted average, a substantial reduction from the prior limit, specifically in response to accumulating evidence of silica-related disease at the older, higher limit (OSHA, 29 CFR 1910.1053).
Silicosis as an irreversible, progressive disease
Unlike some occupational exposures where cessation halts disease progression, silicosis is a fibrotic lung disease that can continue to progress even after exposure ends, and IARC classifies crystalline silica in the form of quartz or cristobalite from occupational sources as carcinogenic to humans (Group 1), reflecting both the fibrotic and carcinogenic dimensions of the disease (IARC, Silica Dust, Crystalline).
Reconstructing exposure in small fabrication shops
Litigation in this industry frequently involves small businesses with limited historical air monitoring, requiring exposure reconstruction based on task-based exposure surveys, industry-standard emission factors for dry versus wet-cutting methods, and OSHA hazard-alert guidance specifically addressing countertop manufacturing, finishing, and installation (OSHA, Hazard Alert: Worker Exposure to Silica during Countertop Manufacturing).
Why worker demographics matter to the litigation
Much of the documented engineered-stone silicosis burden has concentrated among immigrant fabrication workers, a population that may face additional barriers to early diagnosis, workers’ compensation navigation, and English-language occupational safety training, factors that intersect with, but do not substitute for, the underlying exposure reconstruction and dose-response analysis (Fazio et al., 2023).
The all-wet counterfactual as an analytical framework
A recurring analytical approach in this litigation compares a worker’s actual dry-cutting exposure history against a counterfactual scenario in which wet-cutting methods, which substantially reduce airborne respirable silica, had been consistently used throughout the same work history, isolating the incremental risk attributable to inadequate dust-control practices.
Why this litigation area continues to grow
With engineered stone countertops remaining popular in residential and commercial construction and documented worker silicosis cases continuing to accumulate well past the initial 2019 case series, California and other states have continued to see new silicosis diagnoses and associated litigation among fabrication workers. See RoseyFields.com for further detail on Dr. Rosenfeld’s silica exposure assessment work.
References
1. Reyes-Cuevas, et al. v [engineered stone fabrication defendants]. Case No. 23STCV00260, Superior Court of California, County of Los Angeles.
2. Rose C, Heinzerling A, Patel K, Sack C, Wolff J, Zell-Baran L, Weissman D, et al. Severe silicosis in engineered stone fabrication workers — California, Colorado, Texas, and Washington, 2017-2019. MMWR Morb Mortal Wkly Rep. 2019;68(38):813-818.
3. Fazio JC, Gandhi SA, Flattery J, et al. Silicosis among immigrant engineered stone (quartz) countertop fabrication workers in California. JAMA Intern Med. 2023;183(9):991-998.
4. Surasi K, Ballen B, Weinberg JL, Materna BL, Harrison R, Cummings KJ, Heinzerling A. Elevated exposures to respirable crystalline silica among engineered stone fabrication workers in California, January 2019-February 2020. Am J Ind Med. 2022;65(9):701-707.
5. Occupational Safety and Health Administration. Occupational Exposure to Respirable Crystalline Silica. 29 CFR § 1910.1053; 29 CFR § 1926.1153.
6. Occupational Safety and Health Administration. Hazard Alert: Worker Exposure to Silica during Countertop Manufacturing, Finishing and Installation. Washington, DC: US Department of Labor.
7. IARC Working Group on the Evaluation of Carcinogenic Risks to Humans. Silica Dust, Crystalline, in the Form of Quartz or Cristobalite. IARC Monographs on the Evaluation of Carcinogenic Risks to Humans, Vol 100C. Lyon, France: International Agency for Research on Cancer; 2012.
8. National Institute for Occupational Safety and Health. Engineered Stone and Silicosis. NIOSH Science Bulletin. Washington, DC: CDC.
9. Kramer MR, Blanc PD, Fireman E, et al. CaesarStone silicosis: disease resurgence among artificial stone workers. Chest. 2012;142(2):419-424.
10. Hoy RF, Baird T, Hammerschlag G, Hart D, Johnson AR, King P, Putt M, Yates DH. Artificial stone-associated silicosis: a rapidly emerging occupational lung disease. Occup Environ Med. 2018;75(1):3-5.
11. Agency for Toxic Substances and Disease Registry. Toxicological Profile for Silica. Atlanta, GA: US Department of Health and Human Services.
12. Rosenfeld PE. RoseyFields LLC: Silica and Engineered Stone Exposure Assessment. Santa Monica, CA: RoseyFields LLC; 2026.
13. US Environmental Protection Agency. Revisions to the Guideline on Air Quality Models. 40 CFR Part 51, Appendix W. Fed Regist. 2017;82(10):5182-5235.
14. California Division of Occupational Safety and Health (Cal/OSHA). Emergency Regulation on Respirable Crystalline Silica in Engineered Stone Fabrication. Sacramento, CA: Cal/OSHA; 2024.