Labor Code section 6359.1
(a)
“Artificial stone” means any reconstituted, artificial, synthetic, composite, engineered, or manufactured stone product. It is commonly made by combining natural stone or other crystalline silica-containing materials with adhesives, polymers, epoxies, resins, or other binding materials to form a slab. Fired ceramic and porcelain tiles and panels are not artificial stone.(b)
“Department” means the Department of Industrial Relations.(c)
“Director” means the Director of Industrial Relations.(d)
“Division” means the Division of Occupational Safety & Health.(e)
“Dry methods” means the undertaking of high-exposure trigger tasks without the use of wet methods that effectively suppress dust.(f)
(1)“Fabrication shop” means a person, entity, business, or location where high-exposure trigger tasks are undertaken.(2)
“Fabrication shop” does not include quarries, concrete and cement manufacturing facilities, or fired ceramic or fired porcelain tiles or panels manufacturing facilities that do not manufacture, fabricate, or finish artificial stone products.(g)
“High-exposure trigger task” means machining, crushing, cutting, drilling, abrading, abrasive blasting, grinding, chiseling, carving, gouging, polishing, buffing, fracturing, intentional breaking, or intentional chipping of artificial stone that contains more than 0.1 percent by weight crystalline silica, or other silica containing products, including natural stone, that contain more than 10 percent by weight crystalline silica. High-exposure trigger tasks also include clean up, disturbing, or handling of wastes, dusts, residues, debris, or other materials created during the above-listed tasks. High-exposure trigger tasks do not include tasks other than the fabrication of countertops, backsplashes, walls, flooring, waterfall countertop edges, and other products from slabs or panels.(h)
“Respirable crystalline silica” means quartz, cristobalite, or tridymite contained in airborne particles that are determined to be respirable by a sampling device designed to meet the characteristics for respirable-particle-size-selective samplers specified in the International Organization for Standardization (ISO) 7708:1995 Air Quality — Particle Size Fraction Definitions for Health-Related Sampling.(i)
“Wet methods” means effectively suppressing dust by one of the methods listed below, such that exposures do not exceed the action level at any time. Regardless of the method used, water shall cover the entire surface of the work object where a tool, equipment, or machine contacts the work object.(1)
Applying a constant, continuous, and appropriate volume of running water directly onto the surface of the work object. When water flow is integrated with a tool, machine, or equipment, water flow rates shall equal or exceed manufacturer recommendations and specifications to ensure effective dust suppression. Any water that is recycled must be filtered to remove silica prior to reuse.(2)
Submersing the work object underwater.(3)
Water jet cutting or the use of high-pressure water to cut material.
Source:
Section 6359.1, https://leginfo.legislature.ca.gov/faces/codes_displaySection.xhtml?lawCode=LAB§ionNum=6359.1. (updated Jan. 1, 2026; accessed Dec. 22, 2025).
