OSHA’s respirable crystalline silica standard mandates reducing exposures through engineering and work practice controls. Contractors have the flexibility to choose from three different compliance options. One of those options is Table 1, which lists 18 silica-generating tasks along with specific engineering controls and respirator requirements. Employers who follow these requirements fully and completely don’t have to perform air monitoring and will be assumed to be below the permissible exposure limit.
Respirator Requirements and Minimum Assigned Protection Factor (APF) for 4 Hours or Less
Respirator Requirements and Minimum Assigned Protection Factor (APF) for More Than 4 Hours
Stationary masonry saws
Use saw equipped with integrated water delivery system that continuously feeds water to the blade.
Operate and maintain tool in accordance with manufacturer’s instructions to minimize dust emissions.
(None required)
(None required)
Handheld power saws (any blade diameter)
Use saw equipped with integrated water delivery system that continuously feeds water to the blade.
Operate and maintain tool in accordance with manufacturer’s instructions to minimize dust emissions:
– When used outdoors
(None required)
(APF 10 required)
– When used indoors or in an enclosed area
(APF 10 required)
(APF 10 required)
Handheld power saws for cutting fiber-cement board (with blade diameter of 8 inches or less)
For tasks performed outdoors only:
Use saw equipped with commercially available dust collection system.
Operate and maintain tool in accordance with manufacturer’s instructions to minimize dust emissions.
Dust collector must provide the airflow recommended by the tool manufacturer, or greater, and have a filter with 99% or greater efficiency.
(None required)
(None required)
Walk-behind saws
Use saw equipped with integrated water delivery system that continuously feeds water to the blade.
Operate and maintain tool in accordance with manufacturer’s instructions to minimize dust emissions:
– When used outdoors
(None required)
(None required)
– When used indoors or in an enclosed area
(APF 10 required)
(APF 10 required)
Drivable saws
For tasks performed outdoors only:
Use saw equipped with integrated water delivery system that continuously feeds water to the blade.
Operate and maintain tool in accordance with manufacturer’s instructions to minimize dust emissions.
(None required)
(None required)
Rig-mounted core saws or drills
Use tool equipped with integrated water delivery system that supplies water to cutting surface.
Operate and maintain tool in accordance with manufacturer’s instructions to minimize dust emissions.
(None required)
(None required)
Handheld and stand-mounted drills (including impact and rotary hammer drills)
Use drill equipped with commercially available shroud or cowling with dust collection system.
Operate and maintain tool in accordance with manufacturer’s instructions to minimize dust emissions.
Dust collector must provide the airflow recommended by the tool manufacturer, or greater, and have a filter with 99% or greater efficiency and a filter-cleaning mechanism.
Use a HEPA-filtered vacuum when cleaning holes.
(None required)
(None required)
Dowel drilling rigs for concrete
For tasks performed outdoors only:
Use shroud around drill bit with a dust collection system. Dust collector must have a filter with 99% or greater efficiency and a filter-cleaning mechanism.
Use a HEPA-filtered vacuum when cleaning holes.
(APF 10 required)
(APF 10 required)
Vehicle-mounted drilling rigs for rock and concrete
Use dust collection system with close capture hood or shroud around drill bit with a low-flow water spray to wet the dust at the discharge point from the dust collector.
(None required)
(None required)
OR
Operate from within an enclosed cab and use water for dust suppression on drill bit.
(None required)
(None required)
Jackhammers and handheld powered chipping tools
Use tool with water delivery system that supplies a continuous stream or spray of water at the point of impact:
– When used outdoors
(None required)
(APF 10 required)
– When used indoors or in an enclosed area
(APF 10 required)
(APF 10 required)
OR
Use tool equipped with commercially available shroud and dust collection system.
Operate and maintain tool in accordance with manufacturer’s instructions to minimize dust emissions.
Dust collector must provide the airflow recommended by the tool manufacturer, or greater, and have a filter with 99% or greater efficiency and a filter-cleaning mechanism:
– When used outdoors
(None required)
(APF 10 required)
– When used indoors or in an enclosed area
(APF 10 required)
(APF 10 required)
Handheld grinders for mortar removal (i.e., tuckpointing)
Use grinder equipped with commercially available shroud and dust collection system.
Operate and maintain tool in accordance with manufacturer’s instructions to minimize dust emissions.
Dust collector must provide 25 cubic feet per minute (cfm) or greater of airflow per inch of wheel diameter and have a filter with 99% or greater efficiency and a cyclonic pre-separator or filter-cleaning mechanism.
(Half mask required)
(APF 25 required)
Handheld grinders for uses other than mortar removal
For tasks performed outdoors only:
Use grinder equipped with integrated water delivery system that continuously feeds water to the grinding surface.
Operate and maintain tool in accordance with manufacturer’s instructions to minimize dust emissions.
(None required)
(None required)
OR
Use grinder equipped with commercially available shroud and dust collection system.
Operate and maintain tool in accordance with manufacturer’s instructions to minimize dust emissions.
Dust collector must provide 25 cubic feet per minute (cfm) or greater of airflow per inch of wheel diameter and have a filter with 99% or greater efficiency and a cyclonic pre-separator or filter-cleaning mechanism:
– When used outdoors
(None required)
(None required)
– When used indoors or in an enclosed area
(None required)
(APF 10 required)
Walk-behind milling machines and floor grinders
Use machine equipped with integrated water delivery system that continuously feeds water to the cutting surface.
Operate and maintain tool in accordance with manufacturer’s instructions to minimize dust emissions.
(None required)
(None required)
OR
Use machine equipped with dust collection system recommended by the manufacturer.
Operate and maintain tool in accordance with manufacturer’s instructions to minimize dust emissions.
Dust collector must provide the airflow recommended by the manufacturer, or greater, and have a filter with 99% or greater efficiency and a filter-cleaning mechanism.
When used indoors or in an enclosed area, use a HEPA-filtered vacuum to remove loose dust in between passes.
(None required)
(None required)
Small drivable milling machines (less than half-lane)
Use a machine equipped with supplemental water sprays designed to suppress dust. Water must be combined with a surfactant.
Operate and maintain machine to minimize dust emissions.
(None required)
(None required)
Large drivable milling machines (half-lane and larger)
For cuts of any depth on asphalt only:
Use machine equipped with exhaust ventilation on drum enclosure and supplemental water sprays designed to suppress dust.
Operate and maintain machine to minimize dust emissions.
(None required)
(None required)
For cuts of four inches in depth or less on any substrate:
Use machine equipped with exhaust ventilation on drum enclosure and supplemental water sprays designed to suppress dust.
Operate and maintain machine to minimize dust emissions.
(None required)
(None required)
OR
Use a machine equipped with supplemental water spray designed to suppress dust. Water must be combined with a surfactant.
Operate and maintain machine to minimize dust emissions.
(None required)
(None required)
Crushing machines
Use equipment designed to deliver water spray or mist for dust suppression at crusher and other points where dust is generated (e.g., hoppers, conveyors, sieves/sizing or vibrating components, and discharge points).
Operate and maintain machine in accordance with manufacturer’s instructions to minimize dust emissions.
Use a ventilated booth that provides fresh, climate-controlled air to the operator, or a remote control station.
(None required)
(None required)
Heavy equipment and utility vehicles used to abrade or fracture silica-containing materials (e.g., hoe-ramming, rock ripping) or used during demolition activities involving silica-containing materials
Operate equipment from within an enclosed cab.
(None required)
(None required)
When employees outside of the cab are engaged in the task, apply water and/or dust suppressants as necessary to minimize dust emissions.
(None required)
(None required)
Heavy equipment and utility vehicles for tasks such as grading and excavating but not including: Demolishing, abrading, or fracturing silica-containing materials
Apply water and/or dust suppressants as necessary to minimize dust emissions.
(None required)
(None required)
OR
When the equipment operator is the only employee engaged in the task, operate equipment from within an enclosed cab.
