NEW Visit OSHA's Final Rule on Respirable Crystalline Silica page for information on the new final rule.
OSHA’s longstanding policy is that engineering and work practice controls must be the primary means used to reduce employee exposure to toxic chemicals, as far as feasible, and that respiratory protection is required to be used when engineering or work practice controls are infeasible or while they are being implemented.
Where possible, silica should be eliminated or substituted with a safer option. Engineering controls should then be considered, such as using local exhaust ventilation, using containment methods (e.g., blast-cleaning machines and cabinets), and wet sawing or wet drilling of silica-containing materials. Administrative or work practice controls may be appropriate in some cases where engineering controls cannot be implemented or when different procedures are needed after implementation of the new engineering controls. Administrative actions may include limiting workers’ exposure time and requiring workers to shower and change into clean clothes before leaving a worksite. Personal protection equipment is the least desirable, but may still be effective. Use of personal protective equipment may include wearing proper respiratory protection to keep workers' exposure below the OSHA permissible exposure limit and the use of personal protective clothing.
The following references aid in controlling silica hazards in the workplace.
- Controlling Silica Dust from Foundry Casting-Cleaning Operations. US Department of Health and Human Services (DHHS), National Institute for Occupational Safety and Health (NIOSH) Publication No. 98-106 (Hazard Controls 23), (1997, December). The local exhaust ventilation system described in this document may keep worker exposures to respirable silica below permissible limits and eliminate the need for workers to wear respirators.
- Dust Monitoring and Control Downloadable Mining Publications. National Institute for Occupational Safety and Health (NIOSH) Mining Safety and Health Research.
- Dust Control Handbook for Industrial Minerals Mining and Processing. US Department of Health and Human Services (DHHS), National Institute for Occupational Safety and Health (NIOSH) Publication No. 2012-112, (January 2012). Handbook covering engineering controls in mining operations for reducing dust generation and limiting worker exposure.
Resources for the Construction Industry
Controlling the exposure to silica in construction can be done through engineering controls, administrative actions, and personal protective equipment (PPE), similar to practices in other industries. Engineering controls include such things as replacing silica with another material (substitution), isolating an exposure source, and using ventilation systems. Administrative actions include limiting workers’ exposure time and providing showers. Use of PPE includes wearing proper respiratory protection and protective clothing. The following references aid in controlling crystalline silica hazards in the workplace.
- Controlling Silica Exposures in Construction [1 MB PDF, 72 pages]. OSHA Publication 3362-04, (2009). Provides information on the effectiveness of various engineering control approaches for several kinds of construction operations and equipment, and contains recommendations for work practices and respiratory protection.
- OSHA Fact Sheets on Controlling Exposures in Construction While:
- Operating Handheld Masonry Saws [459 KB PDF, 2 pages]
- Operating Stationary Masonry Saws [638 KB PDF, 2 pages]
- Operating Handheld Grinders [374 KB PDF, 2 pages]
- Operating Rotary Hammers [420 KB PDF, 2 pages]
- Operating Vehicle Mounted Rock Drills [869 KB PDF, 2 pages ]
- Jackhammering [456 KB PDF, 2 pages]
- Tuckpointing/Mortar Removal [480 KB PDF, 2 pages]
- NIOSH Silica Controls for Construction Page
- For additional information regarding possible ways of controlling crystalline silica exposures, see OSHA's Safety and Health Topics Pages on:
- Working Safely with Silica. The Center for Construction Research and Training has a website with resources to help contractors and workers understand the health risk involved and implement measures to control dust.