Construction, Regulatory Developments

The Respirable Silica Standard and Handheld Saws

OSHA recently provided guidance about several frequently asked questions about the respirable crystalline silica rule in construction, along with a new set of videos on controlling silica dust generated by several types of equipment.

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Upon the compliance date of a new major standard with multiple requirements, OSHA will generally refrain from strict enforcement (except in cases of willful, serious, or repeated violations) provided the employer is making a good-faith effort to meet the requirements. Sometimes, enforcement will also be restrained until OSHA issues guidance materials to assist businesses, and particularly small businesses, in meeting their obligations to provide safe working environments. Both of these conditions apply to OSHA’s revisions to its standard to control occupational exposure to respirable crystalline silica (March 3, 2016, Federal Register (FR)). The rule comprised separate standards for each of two categories: (1) general industry and maritime and (2) construction; however, both categories are subject to the same permissible exposure limit of50 micrograms of respirable crystalline silica per cubic meter of air.

Construction Guidance Available

Compliance with all obligations under the construction standard, except those related to methods of sample analysis, was required by June 23, 2017. But OSHA has only this week released a new set of frequently asked questions about the respirable silica in construction standard along with a set of videos on controlling silica dust generated by several types of equipment. These items may not be the last word OSHA has on guidance under the standard, but employers should bear in mind that the more guidance OSHA generates, the more likely the Agency will not be patient with violations attributed even to employers that are operating in good faith.

Wet Cutting—First Engineering Control

OSHA’s list of fact sheets on controlling exposures to specific equipment begins with handheld power saws—that is, portable saws used to cut masonry, concrete, stone, or other silica-containing materials. By listing this equipment type first, OSHA is not necessarily stating that handheld sawing presents the highest risk of all equipment types or that more workers use these saws than other equipment types. However, the nature of handheld sawing—production of high levels of fine dust and frequent movement from one sawing task to another—suggests that continuously maintaining engineering controls—the top item in OSHA’s hierarchy of worker protections—may present challenges.

Wet cutting is the preferred engineering control for most operations, including handheld sawing, that produces silica-containing dust. OSHA provides the following directions for wet cutting with handheld power saws:

  • All wet-cutting operations:
    • The saw must be operated in accordance with manufacturer’s instructions to minimize dust emissions.
    • Check that hoses are securely connected and are not cracked or broken.
    • Adjust nozzles so that water goes to the blade and wets the cutting area.
    • Inspect the saw blade before use to be sure it is in good condition and does not show excessive wear.
    • Maintain the operating saw’s dust-control equipment based on the manufacturer’s instructions.
    • Clean up any slurry produced to prevent it from drying and releasing silica dust into the air. Wet slurry can be cleaned up with shovels or a wet vacuum equipped with a high-efficiency particulate air (HEPA) filter.
  • Wet cutting indoors or in enclosed areas:
    • Wet cutting indoors or in enclosed areas may not reliably keep silica exposures low, so extra ventilation or a means of exhaust may be needed to reduce visible airborne dust.
    • Extra ventilation can be supplied by using exhaust trunks, portable exhaust fans, air ducts, or other means of mechanical ventilation.
    • Ensure air flow is not impeded by the movements of employees during work or by the opening or closing of doors and windows. Position the ventilation to move contaminated air away from the workers’ breathing zones.

OSHA’s guidance for the respirable silica standard for construction is at https://www.osha.gov/dsg/topics/silicacrystalline/construction.html.