Regulators and industry groups remain locked in a contentious legal and legislative battle over stronger workplace safety protections.
Resurgence of Occupational Lung Disease
Silicosis, traditionally known as black lung when affecting coalminers, is a preventable occupational disease caused by the inhalation of tiny crystalline silica particles. According to public health experts, modern outbreaks span multiple sectors where workers face intense dust exposure. Coalminer John Robinson was diagnosed with black lung at age 47, decades earlier than his grandfather, who developed the disease after a long mining career and died in his 60s or 70s. “At one time, you didn’t say black lung around the coal site unless you wanted to lose a job. It’s such an outbreak right now they can’t hide it,” Robinson stated.
Since approximately 2018, clinicians have documented severe clusters of lung disease among countertop fabrication workers who cut, grind, and polish engineered stone slabs containing up to 90% crystalline silica. Doctors in Colorado, Texas, and California identified dozens of cases, while a study published in the New England Journal of Medicine later identified nearly 600 cases in California alone, including dozens of workers who required lung transplants and dozens who died.
Regulatory Actions and Industry Pushback
In 2024, the Mine Safety and Health Administration (MSHA) finalized a rule lowering the permissible exposure limit (PEL) for respirable crystalline silica from 100 to 50 micrograms per cubic meter over an eight-hour shift. The rule also added more frequent air sampling and medical surveillance requirements. Within months, industry groups petitioned to overturn the regulation. After the Department of Labor declined to defend the rule under a previous administration, a federal appeals court stayed enforcement, and MSHA announced it would reconsider affected portions of the rule.
The National Stone, Sand & Gravel Association (NSSGA) led the legal challenge against the MSHA rule. The NSSGA states it does not oppose the PEL reduction itself, but objects to the mandated frequency of air sampling and medical surveillance. Meanwhile, the American Exploration & Mining Association (AEMA) supports a lower PEL but argues that MSHA’s implementation approach is excessively inflexible, contending that administrative controls and respirators should remain acceptable where engineering controls are not feasible.
Countertop Fabrication and Engineered Stone Debates
Countertop fabrication workers are nominally covered by a 2016 Occupational Safety and Health Administration (OSHA) standard, but industry groups previously challenged that rule in court as not based on sound science. Public health critics note that engineered stone’s exceptionally high silica content makes cutting, grinding, and polishing these slabs hazardous, rendering the 2016 OSHA standard insufficient on its own.
During a congressional subcommittee hearing in January, discussions frequently centered on protecting manufacturers and retailers from litigation rather than prioritizing worker safety. Epidemiologist David Michaels, formerly OSHA’s assistant secretary and currently at the Milken Institute School of Public Health, told lawmakers that the United States should consider banning the sale of engineered stone with very high silica content, noting that safer substitute materials are comparable in use and cost.
State-level regulators are also pursuing stricter measures. In May, Cal/OSHA opened rulemaking to prohibit the fabrication and installation of artificial stone products containing more than 1% crystalline silica. Stone distributors have objected to the proposal, calling it unnecessary and not feasible.