costs in complying with this new regulation, as they will continue to use the same dust control methods for safer products that they have installed to comply with § 5204.
A more detailed scientific rationale for our request follows. There have been more than 100 scientific articles published over the past decade on the worldwide epidemic of silicosis caused by engineered stone. We recommend several reviews that summarize the evidence and highlight the dangers to workers posed by engineered stone and the need to take urgent policy action. 2 California academic and public health scientists have published many of these articles and can provide extensive scientific and technical knowledge as well.
1. Rising counts of silicosis caused by engineered stone represent a health emergency. Through passive surveillance, the California Department of Public Health( CDPH) continues to track silicosis cases caused by engineered stone. As of December 4, 2025 there were 447 cases with 25 deaths. The median age at diagnosis is 46, and the median age of death is 48. 3 As shown below, since the Board first considered engineered stone for regulatory action in 2023, case counts have continued to rise at an alarming rate:
2
Fazio JC, Gandhi SA, Flattery J, Heinzerling A, Kamangar N, Afif N, Cummings KJ, Harrison RJ. Silicosis Among Immigrant Engineered Stone( Quartz) Countertop Fabrication Workers in California. JAMA Intern Med. 2023 Sep 1; 183( 9): 991-998; Hoy RF, Dimitriadis C, Abramson M, Glass DC, Gwini S, Hore-Lacy F, Jimenez-Martin J, Walker-Bone K, Sim MR. Prevalence and risk factors for silicosis among a large cohort of stone benchtop industry workers. Occup Environ Med. 2023 Aug; 80( 8): 439- 446; Ramkissoon C, Gaskin S, Song Y, Pisaniello D, Zosky GR. From Engineered Stone Slab to Silicosis: A Synthesis of Exposure Science and Medical Evidence. Int J Environ Res Public Health. 2024 May 27; 21( 6): 683; Fazio JC, Viragh K, Houlroyd J, Gandhi SA. A review of silicosis and other silicarelated diseases in the engineered stone countertop processing industry. J Occup Med Toxicol. 2025 Mar 17; 20( 1): 9; Heinzerling A, Harrison R, Flattery J, Fazio JC, Gandhi S, Cummings KJ. Deadly Countertops: An Urgent Need to Eliminate Silicosis among Engineered Stone Workers. Am J Respir Crit Care Med. 2025 Apr; 211( 4): 557-559; León-Jiménez A, Martínez-González C, Cohen RA. Engineered Stone and Silicosis: An Acceptable Risk? Arch Bronconeumol. 2025 May; 61( 5): 259-260.
3 https:// www. cdph. ca. gov / Programs / CCDPHP / DEODC / OHB / Pages / essdashboard. aspx, accessed 11 / 30 / 25.
3