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.
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.
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, 15468-32-3 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.
If you conduct any of the following work tasks, there may be potential exposures to crystalline silica in your operations:
This list is not all inclusive; there are other work tasks that could also result in potential inhalation exposures to crystalline silica.
The following steps can be taken now to prepare for a future crystalline silica standard:
Potential inhalation exposure to crystalline quartz silica can be evaluated by reviewing historical sampling data if prior air monitoring has been conducted, and comparing the results to the proposed OSHA PEL provided the sampling data is still representative of the work tasks conducted. If representative sampling data is not available, then personal sampling should be conducted for workers to evaluate their potential inhalation exposures.
You do not need to be a certified industrial hygienist (CIH) to conduct air sampling. The key to sampling is to follow best practices and good industrial hygiene practices. Instructional videos are available at travelerslab.com. These instructional videos provide useful, step-by-step instructions on how to conduct proper air sampling. The videos can be viewed online or downloaded to your computer for later viewing. They demonstrate sampling equipment set-up, data collection and equipment handling. The instructional videos that are applicable to sampling for respirable crystalline silica include:
To sample for respirable crystalline silica, the primary equipment you will need includes a high-flow pump, a respirable dust cyclone, PVC filter cassettes and a calibrator. The pump must be calibrated to a prescribed flow rate as determined by the specific cyclone being used.
The Travelers Industrial Hygiene Laboratory has all of the sampling equipment you need to conduct effective air sampling. In addition, pump rentals and media are free when you send your samples in to the Travelers AIHA-accredited laboratory for analysis. This process is both convenient and timely and helps make sampling easy. The needed sampling equipment can be ordered from: travelerslab.com.
This process can help you to evaluate the silica exposures within your workplace and to implement any controls or process changes before OSHA publishes its final rule on occupational exposures to respirable crystalline silica.
Coming Soon! Watch for our video about evaluating silica, which will be posted on the instructional video page of travelerslab.com.