Crystalline silica regulation by jurisdiction

Regulatory approaches divide into two families. Some jurisdictions restrict theproduct, defining a threshold of crystalline silica content above which engineered stone may not be supplied or processed. Others regulate theexposure, setting an airborne limit and requiring controls regardless of what the material contains. Australia took the first route; Great Britain takes the second; the United States regulates exposure federally while California moves toward a product restriction.

Where a product threshold has been set or proposed, the figure has consistently been 1% crystalline silica by weight.

41 materials in the registry have a manufacturer-published maximum of 1% crystalline silica or less. That is the same numeric boundary Australia's ban and California's proposed rulemaking are built on, though whether any specific material falls within either law depends on more than silica content alone (Australia's ban, for example, also requires the product to be an artificial stone in benchtop, panel or slab form). This is not a statement about any material's legal status in any jurisdiction: confirm that with the relevant authority.

A further 63 materials are classified Zero-Silica in the registry, a classification that may rest on a published maximum or on a manufacturer claim with no figure attached (seehow tiers are defined).

This is regulatory information, not legal advice or compliance certification. Positions change, implementation varies within federal jurisdictions, and readers must confirm the current position with the named authority before relying on it.