

Solution: Using an Air-Purifying Respirator (APR)

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	Description:	Respirators are a last resort when engineering and work practice methods have already been used to control harmful exposures to the extent feasible or while those methods are being implemented. Respirator use must be part of a complete respiratory protection program. The employer must determine that respirators users are medically cleared to wear a respirator and trained in the proper donning, use and maintenance of the assigned device. Reusable respirators must be properly maintained, cleaned and stored. Fit testing is an essential part of a respiratory protection program. A respirator must be selected based on the type and level of hazard exposure. A respirator must either be supplied with air that meets OSHA standards or be fitted with air purifying cartridges or filters that are matched to the exposure. This solution addresses only air purifying respirators. Respirator use is a last resort when feasible engineering and work practice methods are not fully effective in controlling harmful airborne exposures to below allowable limits. Even if respirators will still be necessary: use chemical products that produce the lowest hazard levels while meeting specifications use the best available ventilation limit unnecessary access to the contaminated area to the extent feasible avoid entering areas of elevated exposure to materials used by other workers whenever feasible. air contaminants may still not be adequately controlled even when following these and other engineering and work practice methods. Use respiratory protection to control the remaining exposure If you work as an independent contractor you can obtain respirator selection and use information from the manufacturer of the respirator that you are using. Some safety supply companies also offer expert guidance. With regards to selecting the approriate respirator and filters/cartridges, information is available from 3M, NIOSH and North. You must know what you are exposed to and what the level of exposure is to properly select a respirator and filters/cartridges. Do not use an air purifying respirator in an Immediately Dangerous to Life or Health (IDLH) environment, including oxygen deficient atmospheres (less than 19.5% O2) The following information applies to the use of an air purifying respirator (APR). If you wear an air purifying respirator at work: Use only a model and size for which you have been successfully fitted. Unfitted respirators may not provide effective protection. Ensure that there is no beard or hair in the respirator sealing area. Even a light beard can break the seal, also known as a "break-through," and does not act as an effective filter. Fit check the respirator and adjust the straps until you have a reliable seal. Make sure that you install the correct cartridge for the exposure. Refer to the product MSDS if you are not sure about what's in the materials that you are using. Compare your exposure to the respirator manufacturer's cartridge selection chart or web tool. Respirator bodies and filters/cartridges are certified as a unit - do not mix component from different manufacturers. Follow your employers cartridge change schedule but if you smell the contaminant or feel irritation or other symptom of exposure while wearing the respirator, there may be a break-through. Leave the exposure area and change the cartridges even if it is before the specified change time. If you experience difficulty in breathing, the filters/cartridges may be overloaded, or "saturated," and should be changed. If there is evidence of deterioation, the filters/cartridges may not work effectively anymore and should be changed. Start the day with a fresh filter or cartridge. Do not reuse a chemical cartridge on a second day. When you finish for the day, clean and properly store the respirator. Remove and discard the cartridges or filters. Filters remove solid particles and aerosols but not vapors or gases. They are rated for three levels of oil resistance and three levels of efficiency. The classification of "N" means the filter is not resistant to oil; "R" means the filter can resist oil and "P" means that the filter is oil-proof. A "P" or "R" filter must be used when oil mists are present. Filters are rated at 95%, 99% or 99.97% efficiency. 99.97% efficiency filters are labeled at 100. An N95 filter (commonly used in general construction) is acceptable if you only need to remove 95% of particles in an oil free environment. Higher rated filters are needed in more extreme situations. Filter efficiency must also be factored in when calculating the maximum use level of a respirator. For a half-face respirator with an N95 filter, the total leakage is calculated as 10% (around the face piece) + 5% (through the filter). Therefore the combination can only be used in atmospheres up to 6.67 times the exposure limit. For chemical cartridges, a qualified person must establish a cartridge change schedule. It is essential to know the nature and level of all contaminants that will or may be in the workplace air in order to select a respirator and filter and to establish a cartridge change schedule. Work level, humidity and altitude will also effect respirator selection and performance. For painting tasks a filter-organic vapor cartridge may be required and a pre-filter may also be used to limit filter overloading. Etools are available that can provide expert guidance in determining medical clearance to wear a respirator, selecting respirators and cartridges, and in establishing cartridge change schedules. OSHA provides a compliance guide for small employers with references to applicable standards and Cal OSHA provides an extensive guide to respirator selection and use, including fit checking. cleaning and storage. For work with lead, asbestos, or methylene chloride you and your employer must adhered to additional specific requirements for respirator selection. If you elect to voluntarily wear a respirator, even though you are not legally overexposed, you may do so, but your employer must include you in the respiratory protection program unless the respirator that you select is a filtering face piece. If you voluntarily wear a filtering face piece your employer only needs to provide you with a copy of Appendix D of the respiratory protection standard. Surgical masks, bandanas or other non-certified filters do not provide reliable protection. For reliable protection, use a NIOSH certified filtering face piece. More Detail
	Risks Addressed:	Airborne toxic dusts, mists, vapors, mists, and fumes. Air purifying respirators filter but do not provide breathing air and are not reliably effective against most gases, especially carbon monoxide.
	How Risks are Reduced:	Air purifying respirators form a tight seal around the face. Solid contaminants are removed by the filters. The ability of filters to remove particles is limited by the pore size of the filter. Vapors are removed by packing material inside the cartridge that physically or chemically causes the contaminant to adhere to the filtering media. The ability of a chemical cartridge to remove contaminants is limited by the affinity of the packing material for the contaminant and by the amount of surface areas within the packing for all vapors in the air, including water, to adhere to.
	Quality of Evidence (Risk Reduction):	Independent published studies have found a risk reduction. Manufacturers, vendors, or worksites have reported a risk reduction. Safety and health experts believe there is a risk reduction.
	Quality of Evidence Explanation (Risk Reduction):	Air-purifying respirators work by either filtering particles from the air or chemically cleaning (purifying) the air. Solid contaminants are removed by "filters" when the user breathes in through the respirator. Likewise, vapors are removed by the chemical media, located inside "cartridges," that can physically or chemically cause the contaminant to adhere to. The ability of a chemical cartridge to remove contaminants is limited by the affinity of the packing material for the contaminant and by the amount of surface areas within the packing for all vapors in the air, including water, to adhere to. Also, to ensure that a particular respirator performs as the manufacturer claims, NIOSH established the National Personal Protective Technology Laboratory (NPPTL) as one of the research laboratories to help certify these APRs under NIOSH 42 CFR Part 84.
	Effects on Productivity:	Respirators may slow the work process and reduce productivity.
	Return on Investment:	To calculate the return on investment (ROI) for your specific application, please visit our Return on Investment Calculator. While a specific ROI example has not been developed for this particular solution, the ROI Calculator provides a useful tool and guidance on how to generate your own on investment analysis.
	Hazards Addressed:	Insulation & Lagging Blow and place insulation Construction dust Install and apply fire stop products Construction dust Maintain and remove old insulation including asbestos Construction dust Place finished insulation around duct, pipes, tanks, vessels and mechanical equipment Construction dust