Write a toolbox talk on constraction, dust

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# Regulated and restricted access areas ([redacted phone]) (cont.) ## The written exposure control plan (cont.) Exposure control at construction sites: For construction activities, you must designate a competent person to implement the written exposure control plan and reg- ularly inspect job sites, materials, and equipment. You can designate any of your employees to be a compe- tent person if the person: • Can identify silica dust hazards at the construction site - Is authorized to promptly eliminate or minimize the hazards at the site • Has the knowledge and ability to implement the written exposure control plan for the site Yearly review of written exposure control plan: You must review and evaluate the effectiveness of the written exposure control plan at least once a year and update it as necessary to ensure the information is current. Availability of the written exposure control plan: Allow the written exposure control plan to be viewed or cop- ied by each employee covered by Oregon OSHA's silica rules and their designated representatives. Abrasive blasting: If your employees do abrasive blast- ing that uses crystalline silica blasting agents you must follow all of the requirements for the written exposure control plan and the requirements in Oregon OSHA's ventilation rules (see [redacted phone].94). ## Respiratory protection ([redacted phone]) Employees exposed to silica dust must wear respirators when: • Engineering controls are being installed or work practice controls implemented and their exposures exceed the PEL - Engineering and work practice controls are not feasible and their exposures exceed the PEL • Engineering and work practice controls are not suf- ficient to keep their exposures at or below the PEL • They are working in a regulated or restricted access area When respirators are required, you must also have a respiratory protection program that meets the require- ments of Oregon OSHA's respiratory protection rules (see 1910.134). …

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OSHA FactSheet CONTROL SILICA DUST Breathe Easier # CONTROL OF SILICA DUST IN CONSTRUCTION Handheld Grinders for Mortar Removal (Tuckpointing) The use of a handheld grinder to remove mortar when tuckpointing can generate respirable crystalline silica dust. When inhaled, the small particles of silica can irreversibly damage the lungs. This fact sheet describes control measures to minimize the amount of airborne dust when using handheld grinders to remove mortar between brick, stone, and concrete blocks as listed in Table 1 of the Respirable Crystalline Silica Standard for Construction, 29 CFR 1926.1153. ## Engineering Control Method: Vacuum Dust Collection System ## Vacuum Dust Collection System (VDCS) A VDCS can be used to capture the dust generated when removing mortar with a handheld grinder. Employers can comply with Table 1 in the silica standard by using a: . Commercially available shroud on the grinding wheel designed to fit the grinder and wheel size. - Vacuum that provides at least 25 cubic feet per minute (cfm) of airflow per inch of blade to capture dust at the point of grinding and removing mortar. For example, a 5" grinding wheel would require a rating of 125 cfm of air flow or more for effective capture. . Vacuum equipped with a cyclonic pre- separator or filter- cleaning mechanism with a filter that has 99 percent or greater collection efficiency for respirable-sized particles. • Vacuum exhaust hose capable of providing the airflow recommended by the tool manufacturer. A 1.5" to 2" diameter vacuum exhaust hose is typically adequate. The grinder and dust collector must be operated and maintained in accordance with the manufacturer's instructions to minimize dust emissions. VDCSS are most effective when workers are properly trained and use good work practices, including: • Make sure to keep the vacuum hose clear and free of debris, kinks, and tight bends. • Follow the equipment manufacturer's directions on how to reduce dust buildup on the…

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OSHA FactSheet CONTROL SILICA DUST Breathe Easier # CONTROL OF SILICA DUST IN CONSTRUCTION ## Drivable Saws Using a drivable saw to cut masonry, concrete, stone, or other silica-containing materials can generate respirable crystalline silica dust. When inhaled, the small particles of silica can irreversibly damage the lungs. This fact sheet describes dust controls that can be used to minimize the amount of airborne dust when using drivable saws as listed in Table 1 of the Respirable Crystalline Silica Standard for Construction, 29 CFR 1926.1153. Engineering Control Method: Water continuously fed to saw blade ## Wet Cutting Wet cutting is an effective method to reduce exposure to silica dust when outdoors using drivable saws equipped with an integrated water delivery system. This system directs a continuous stream of water onto the blade where it wets the materials being cut and reduces the amount of dust generated. These saws have built-in water tanks, or water is supplied to the saw from a source such as a hose connected to a faucet or portable tank. Water flow rates must be sufficient to minimize the release of visible dust. A construction worker cutting pavement using a drivable saw with an integrated water delivery system. The saw must be operated and maintained in accordance with manufacturers' instructions to minimize dust emissions. Focus on the following areas: • 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. Clean up any slurry produced during wet cutting to prevent the slurry from drying and releasing silica dust into the air. Wet slurry can be cleaned up using shovels or a wet vacuum equipped with a HEPA filter. If employers operate drivable saws indoors or in an enclosed area, they must conduct an exposure assessment and may need to take…

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# CONTROL OF SILICA DUST IN CONSTRUCTION Handheld Grinders for Mortar Removal (Tuckpointing) (cont.) ## Vacuum Dust Collection System (VDCS) (cont.) Proper handling of the handheld grinder is very important. Ensure the following occurs: • Place one side of the shroud against the working surface before inserting the blade into the mortar joint. This directs the dust into the shroud as the blade cuts into the mortar joint. - Keep the shroud tight against the working surface. This cuts down on dust that would otherwise escape from the collection system. • Move the grinder counter to the direction of blade rotation to minimize escaping dust. - Back off the cutting pressure of the blade a short distance before removing it from the slot so the vacuum can have enough time to clear any dust buildup. - Do not move the grinder back and forth along the slot, as this will create a gap that increases dust escape. For better results, move the grinder in one direction, making a second pass only if necessary. • Use only enough cutting force to operate the tool effectively and keep the leading tool edge flush against the working surface. Do not leave a large gap between the shroud and uncut mortar. Use of Compressed Air. Unless there is a ventilation system that effectively captures the dust cloud, do not use compressed air or blowers to clean surfaces, clothing, or filters because it can increase exposure to silica. Instead, clean with a HEPA filter-equipped vacuum or by wet methods. ## Indoors or in Enclosed Areas Using a VDCS indoors or in an enclosed area may not reliably keep exposure low, so extra ventilation may be needed to reduce visible airborne dust. Extra ventilation can be supplied by using: • Exhaust trunks • Portable exhaust fans • Air ducts • Other means of mechanical ventilation Photo courtesy Worker is showing a handheld grinder equipped with shroud. Ensure air flow is not impeded by the movements of employees during work, or by the opening or …

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OSHA FactSheet CONTROL SILICA DUST Breathe Easier # CONTROL OF SILICA DUST IN CONSTRUCTION Crushing Machines Using crushing machines at construction sites to reduce the size of large rocks, concrete, or construction rubble can generate respirable crystalline silica dust. When inhaled, the small particles of silica can irreversibly damage the lungs. This fact sheet describes dust controls that can be used to minimize the amount of airborne dust when using crushing machines as listed in Table 1 of the Respirable Crystalline Silica Standard for Construction 29 CFR 1926.1153. ## Engineering Control Method: Wet Methods AND Operator Isolation The use of water sprays or mists for dust suppression at the points where dust is generated (e.g., hoppers, conveyers, sieves/ sizing or vibrating components, and discharge points) can control dust exposures when operating crushers. In addition, operator isolation through the use of a remote control station or ventilated booth that provides fresh, climate-controlled air to the operator must also be used to control exposure when operating crushers at construction sites. Photo courtesy of Screen Machine Industries Crushing machine being loaded with construction debris by an excavator. ## Wet Methods Wet spray methods can greatly reduce the silica exposure levels of operators and laborers who work near crushers, tending the equipment, removing jammed material from hoppers, picking debris out of the material stream, and performing other tasks. The crusher must be operated and maintained in accordance with the manufacturer's instructions to minimize dust emissions. Make sure to: . Locate nozzles upstream of dust generation points. • Position nozzles to thoroughly wet the material. • Ensure the volume and size of droplets is adequate to sufficiently wet the material (optimal droplet size is between 10 and 150 μm). - Ensure nozzles provide complete water coverage but are not so far that the water is carried away by wind. ##…

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OSHA FactSheet CONTROL SILICA DUST Breathe Easier # OSHA's Respirable Crystalline Silica Standard for Construction Workers who are exposed to respirable crystalline silica dust are at increased risk of developing serious silica-related diseases. OSHA's standard requires employers to take steps to protect workers from exposure to respirable crystalline silica. ## What is Respirable Crystalline Silica? Crystalline silica is a common mineral that is found in construction materials such as sand, stone, concrete, brick, and mortar. When workers cut, grind, drill, or crush materials that contain crystalline silica, very small dust particles are created. These tiny particles (known as "respirable" particles) can travel deep into workers' lungs and cause silicosis, an incurable and sometimes deadly lung disease. Respirable crystalline silica also causes lung cancer, other potentially debilitating respiratory diseases such as chronic obstructive pulmonary disease, and kidney disease. In most cases, these diseases occur after years of exposure to respirable crystalline silica. ## How are Construction Workers Exposed to Respirable Crystalline Silica? Exposure to respirable crystalline silica can occur during common construction tasks, such as using masonry saws, grinders, drills, jackhammers and handheld powered chipping tools; operating vehicle- mounted drilling rigs; milling; operating crushing machines; using heavy equipment for demolition or certain other tasks; and during abrasive blasting and tunneling operations. About two million construction workers are exposed to respirable crystalline silica in over 600,000 workplaces. ## What Does the Standard Require? The standard (29 CFR 1926.1153) requires employers to limit worker exposures to respirable crystalline silica and to take other steps to protect workers. Employers can either use a control method laid out in Table 1 of the construction standard, or they can measure workers' exposure to silica and independen…

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# Oregon OSHA's silica rules (cont.) ## Observing air monitoring (cont.) ## Table 1 and specified exposure control methods ([redacted phone]) Table 1 lists 18 common construction tasks that create high levels of silica dust and describes the engineering controls, work practices, and respiratory protection necessary for each task. When your employees do construction work and follow the control methods in Table 1, you are not required to conduct an exposure assessment. A common misunderstanding about Table 1 is that respirators are always necessary to protect employees. Respirators are necessary for some Table 1 tasks, but only when engineering and work practice controls do not keep silica dust at acceptable levels. # Regulated and restricted access areas ([redacted phone]) Only authorized employees may enter areas where they could be exposed to silica dust above the PEL. These areas are called regulated areas at fixed sites and restricted areas at construction sites. ## Regulated areas The purpose of a regulated area is to: - Ensure that employees know that silica exposure lev- els in the regulated area are likely to exceed the PEL • Minimize the number of employees who could be exposed to silica dust . Ensure that anyone who enters the regulated area is protected with an appropriate respirator Establishing regulated areas. Establish regulated areas where exposures to silica dust are, or could be, greater than the PEL. You can use any combination of air monitoring data or objective data to establish and mark regulated areas. Marking regulated areas. You must mark off reg- ulated areas from the rest of the workplace. Cones, stanchions, tape, barricades, lines, or textured flooring are some of the ways of marking the boundaries. Posting danger signs. You must also post a sign at each entrance to the regulated areas that reads: DANGER RESPIRABLE CRYSTALLINE SILICA MAY CAUSE CANCER CAUSES DAMAGE TO LUNGS WEAR RESPIRATORY PROTECTION IN THIS AREA AUTHOR…