California timeline: the engineered-stone silicosis outbreak
Medical, surveillance, regulatory, legislative and litigation events in one sequence, newest first. Each entry links to its full record.
Dates are shown to the precision the source supports: a day, a month or a year. Entries labelled "reported by an interested party" rest on a law-firm release or trade press and are included because no better source exists yet.
How to read the verification labels
- Verified: primary source
- Checked by this project against a court record, statute, agency publication or journal index.
- Verified: secondary source
- Checked against a major news organisation, professional body or university publication.
- Reported by an interested party
- Rests on a law-firm release, trade press or legal-marketing site. Treat figures as claims until independently confirmed.
- Unverified
- Listed for completeness; not yet checked against any source by this project.
Tier numbers next to sources (T1 to T4) follow the source hierarchy in the methodology: T1 primary records and agencies, T2 major news and professional bodies, T3 interested parties, T4 discovery-only.
2026
- September 2026Medical research
NEJM Evidence publishes CDPH's 2019-2026 surveillance report
592 cases through June 2026, 65 transplants, 31 deaths.
- 19 August 2026Litigation
Orange County jury awards $7.1 million against Dal-Tile and Bedrosians
Wrongful-death verdict for the family of Gerardo Ramirez-Soriano.
- 13 August 2026Public health surveillance
CDPH count reaches 631 cases, 74 transplants, 35 deaths
As reported by Healio from the CDPH dashboard.
- 3 August 2026Litigation
Los Angeles jury assesses $47 million against Dal-Tile
Wrongful-death verdict for the family of Willmer Ruben Martinez Paredes; Dal-Tile entities 3% fault each, employers 70%.
- 1 July 2026Legislation
First SB 20 training attestations due to Cal/OSHA
Annual employer certification of training for high-exposure trigger tasks.
- 26 June 2026Medical research
American Thoracic Society publishes its workshop report on artificial-stone silicosis
Concludes that hazardous exposures persist despite wet methods, ventilation and respirators.
- 3 June 2026Legislation
House Judiciary Committee orders H.R. 5437 reported, 16 to 7
Bill advances as amended; awaits floor action.
- 21 May 2026Regulation
Standards Board votes to begin rulemaking toward a California ban
Petition 609 granted in part; Cal/OSHA directed to prepare an emergency finding and convene advisory committees.
- 30 April 2026Litigation
Denver jury awards $17.45 million in the first Colorado case
Cambria found liable for misrepresentation (32% fault) and Hyundai L&C for negligence (3%); Caesarstone, DuPont and Makita not liable. Cambria says it will appeal.
- 26 February 2026Regulation
OSHA and NIOSH update the countertop silica hazard alert
NIOSH 2026-101 / OSHA HA-3768-2026.
- February 2026Litigation
Settlements exceeding $20 million reported during a Los Angeles trial
Reported by plaintiff counsel; parties not disclosed.
- 14 January 2026Legislation
House Judiciary subcommittee hearing on H.R. 5437
'Between a Rock and a Hard Place: Protecting the American Stone Slab Industry'. Former OSHA head David Michaels and California physicians testify against the bill.
- 1 January 2026Legislation
SB 20 takes effect
Dry fabrication of artificial stone prohibited statewide.
2025
- December 2025Regulation
WOEMA petitions the Standards Board to prohibit high-silica artificial stone
Petition 609, backed by more than 600 health professionals, seeks a ban on fabrication and installation of artificial stone over 1% crystalline silica.
- 13 November 2025Public health surveillance
CDPH count reaches 432 cases, 25 deaths, 48 transplants
Los Angeles County 226 cases, Orange County 86.
- 13 October 2025Legislation
Governor signs SB 20, the STOP Act
Chapter 734. Bans dry methods on artificial stone, requires annual training attestations and treats artificial-stone silicosis as a serious injury.
- 17 September 2025Legislation
H.R. 5437 introduced in the US House
Protection of Lawful Commerce in Stone Slab Products Act, sponsored by Rep. Tom McClintock, would bar silica-injury suits against slab manufacturers and sellers.
- June 2025Public health surveillance
Silicosis becomes a reportable disease in California
Providers must report within seven days to the local health department.
- 29 May 2025Litigation
Torrance jury returns the first defense verdict, for Caesarstone
Jury finds no negligence and no design defect in the Garcia-Leon wrongful-death case after less than a day.
- April 2025Litigation
Confidential settlements exceeding $26 million reported during jury selection in Los Angeles
Reported by plaintiff counsel; parties not disclosed.
2024
- 19 December 2024Regulation
Standards Board makes the silica emergency standard permanent
Unanimous vote; effective after Office of Administrative Law approval in early 2025.
- 7 August 2024Litigation
First US engineered-stone silicosis verdict: $52.4 million
Los Angeles jury finds Caesarstone (15%), Cambria (10%) and Color Marble (2.5%) at fault for Gustavo Reyes Gonzalez's silicosis.
- 1 July 2024International
Australian engineered-stone ban takes effect
World-first prohibition on manufacture, supply, processing and installation of engineered stone benchtops, panels and slabs.
2023
- 14 December 2023Regulation
California Standards Board adopts the emergency silica standard
Effective 29 December 2023 for one year; targets high-exposure trigger tasks on artificial stone.
- 13 December 2023International
Australian WHS ministers agree to ban engineered stone
Ban to commence 1 July 2024.
- September 2023Medical research
JAMA Internal Medicine publishes the California case series
52 patients, 51 of them Latino immigrants; 19% fatal at a median age of 46.
2022
- September 2022Litigation
Reyes Gonzalez lawsuit filed in Los Angeles
Filed against 34 slab manufacturers and suppliers; becomes the first US engineered-stone silicosis case to reach a jury.
- September 2022Medical research
Cal/OSHA inspection data show 25% of sampled California fabrication workers above the PEL
Analysis of 152 employees at 47 workplaces, 2019-2020.
2019
- 27 September 2019Medical research
CDC reports 18 US cases and the first two US deaths
MMWR report covering California, Colorado, Texas and Washington.
- January 2019Public health surveillance
CDPH identifies the index California case
A 32-year-old fabrication worker is identified; workplace screening finds further cases. CDPH surveillance of engineered-stone silicosis begins.
2018
- January 2018Medical research
Australian case series describes rapidly progressive artificial-stone silicosis
Seven workers, median 7 years' exposure, six with progressive massive fibrosis.
2016
- 25 March 2016Regulation
OSHA publishes the respirable crystalline silica final rule
81 FR 16286. PEL of 50 ug/m3; effective 23 June 2016.
2015
- 2015Regulation
OSHA and NIOSH issue a hazard alert on silica in countertop fabrication
Federal agencies warn that cutting and finishing stone countertops can expose workers to silica above the PEL.
2012
- August 2012Medical research
First major clinical series of artificial-stone silicosis published (Israel)
Kramer and colleagues report 25 transplant-referred silicosis patients, all exposed by dry-cutting a high-silica artificial stone.
Reading the sequence
Three things stand out when the events are lined up. Regulation has lagged the medicine by roughly a decade: the Israeli series was published in 2012, the first California standard specific to artificial stone took effect at the end of 2023. Each regulatory step has been followed by a higher case count, not a lower one, which is the argument now being made to the Standards Board for a ban. And the litigation is a state-court story: five trials, four for plaintiffs, all in California and Colorado, with a federal bill that would end it moving through the House at the same time.
See also the regulation register, the verdict tracker and the research timeline.