On Sept. 12, 2013, OSHA published proposed standard 29 CFR 1910.1053, “Occupational Exposure to Respirable Crystalline Silica” for regulating occupational exposures to respirable crystalline silica. This proposed standard covers general industry, construction, and maritime industries. Although the final rule and the specific provisions still may not be completed for more than a year, the standard will require baseline exposure monitoring to evaluate workers’ inhalation exposures to respirable crystalline silica. In the meantime proactive measures can be taken to help minimize the potential impact of the standard.

• OSHA's Crystalline Silica Rule: Construction
• OHSA's Crystalline Silica Rule: General Industry and Maritime

What is Crystalline Silica?

Respirable crystalline silica, very small particles at least 100 times smaller than ordinary sand you might encounter on beaches and playgrounds, is created during work operations involving stone, rock, concrete, brick, block, mortar and industrial sand. Potential inhalation exposures to respirable crystalline silica can occur when cutting, sawing, grinding, drilling and crushing these materials. These exposures are common in brick, concrete and pottery manufacturing operations, as well as during operations using industrial sand products, such as in foundries, sand blasting, and hydraulic fracturing (fracking) operations in the oil and gas industry.

Do I Have Crystalline Silica in My Workplace?

The chemical inventory and associated safety data sheets (SDSs) for materials used in your operations or manufacturing processes can be reviewed to determine if there are any materials handled or processed that may contain crystalline silica. Crystalline silica can be found in concrete, abrasive blasting agents, paints and coatings, abrasive sanding materials, foundry sands, naturally occurring materials such as granite and stone, polishing materials, dry additives, buffing compounds, and other materials.

On the SDS, crystalline silica may be referred to as quartz, cristobalite, tridymite, crystalline silica, silicone dioxide, crystallized silicon dioxide, and others. The applicable CAS numbers include: 14464-46-1, 14808-60-7,5468-32-3 and 1317-95-9. It should be noted that there are other materials commonly used in industry and construction that can be mistaken for crystalline silica. These include silicon, silicates and silicone. These materials are not crystalline silica.