Silica dust and countertop fabrication: what the federal guidance says

The federal limits

The construction standard 29 CFR 1926.1153 sets an action level of 25 micrograms per cubic meter and a permissible exposure limit of 50 micrograms per cubic meter, both as 8-hour time-weighted averages. Its Table 1 specifies integrated water delivery for stationary masonry saws and handheld power saws, and for handheld grinders either water delivery outdoors only or a shroud with dust collection of at least 25 cfm per inch of wheel diameter. No Table 1 entry names countertops or stone by that word, and fabrication shops fall under the general industry standard rather than the construction one.

What the 2026 hazard alert covers

The joint OSHA and NIOSH hazard alert covers workers who manufacture, finish and install natural and engineered stone countertops, in shops and during on-site finishing and installation. It publishes typical crystalline silica content as under 0.2 to 95 percent for engineered stone, 95 percent or more for quartzite, 10 to 50 percent for granite, under 5 percent for marble and limestone, and varying for soapstone. It recommends checking safety data sheets and choosing lower-silica products, wet methods and local exhaust ventilation, no dry cutting and no compressed air, doing as much work as possible in the shop, and performing unavoidable on-site finishing outdoors with water. It states that employers must comply with the general industry or construction standard, including exposure assessment, a written exposure control plan, respirators where exposures exceed the permissible limit, and medical surveillance. The alert is advisory, states that it creates no new legal obligation, and does not address homeowners.

Why the alert exists

A 2019 MMWR report described 18 silicosis cases among engineered stone fabrication workers in California, Colorado, Texas and Washington, including two deaths, and stated that silicosis is preventable. That report put engineered stone above 90 percent crystalline silica against under 45 percent for granite; the 2026 alert gives a different granite range. Both ranges are recorded here rather than reconciled. The report included no Florida cases.

What the manufacturers publish about it

Several brands now address silica directly on their own pages. Caesarstone describes ICON as a blend that eliminates crystalline silica, footnoted as possibly containing traces of less than one percent. Wilsonart names low-silica styles under 40 percent crystalline silica. Daltile's Purevana page states crystalline silica both as as low as zero in some formulations and as less than 5 percent, and its quartz and porcelain pages refer fabricators to the safety data sheet and to local OSHA guidelines. MSI links silica safety resources and safety data sheets for the trade from its granite page. These are each brand's statements about its own products; no figure here was independently tested.

The question worth asking

Most cutting happens in a shop, but sink cutouts, seam work and edge adjustments are sometimes finished in the house. The federal guidance's own recommendation is to do as much as possible in the shop and to take unavoidable on-site finishing outdoors with water. Asking which cuts will happen on site, and how, is a reasonable question to put to a fabricator. This guide does not answer it for any shop.