California Engineered Stone Rules
Engineered stone (often sold as quartz countertops) can contain more than 90 percent crystalline silica, far more than natural stone. Cutting, grinding and polishing it creates huge amounts of fine silica dust. Many young workers have developed severe, sometimes fatal, silicosis. California has taken some of the strongest steps in the country.
- Countertop Fabricators
- Installers
- California
Why it is dangerous
- Silica dust scars the lungs, causes silicosis (which can progress even after exposure stops) and can lead to lung cancer, kidney disease and autoimmune disease. See Silica.
- Fabrication shops cut and grind slabs with high-speed tools, producing intense exposure in small spaces.
- Severe disease has appeared in workers in their 20s and 30s.
What California has done
This summary may be out of date; confirm with Cal/OSHA.
- Cal/OSHA adopted an emergency, and later permanent, regulation for workplaces working with engineered stone and other high-exposure silica materials. It tightened the rules of the general silica standard.
- Employers with high exposure trigger tasks (such as cutting, grinding, polishing or sanding engineered stone, and other high-silica materials) must follow stricter rules, with requirements to use wet methods or equivalent controls, exhaust ventilation and clean up using HEPA vacuums or wet methods.
- Employers must have an exposure control plan, air monitoring, training in language workers understand, respiratory protection and medical surveillance with spirometry and chest X-rays reviewed in set ways. See Lung Function Tests & Chest X-Rays.
- California law also introduced requirements for notice and information about silica hazards for engineered stone fabricators and set rules for who may work with the material (such as a registration or licensing requirement for certain fabricators).
- Agencies have studied further restrictions, including limits on products. Other states and OSHA have been considering their own rules.
What workers should expect
- Wet cutting and grinding as the default, with water supply and slurry control
- Tools with built-in dust collection and shop ventilation that keeps dust out of your breathing zone
- No dry sweeping and no compressed air to clean up
- Respirators properly fit-tested and medical clearance. See Respiratory Protection
- Washing facilities, and clean clothing programs so dust is not taken home. See Take-Home Contamination
- Regular medical checks, and records you can see
If you think your shop is unsafe
You can ask for air monitoring results and the written plan, request medical exams and file a complaint with Cal/OSHA. Retaliation is illegal. See California and Stone Countertop Fabrication.
Standards & references
Last updated: