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Respitory Protection Devices

Respirators will not provide complete protection against airborne contaminant. All have limits of protection. Properly used, they reduce the level of exposure to or below that considered acceptable by 21st century standards. Selection the proper respirator for a particular hazard is fundamental to hazard reduction. Only respirators tested and certified by National Institute for Occupational Safety and Health (NIOSH) should be used.

There are two primary classes of respirators: air-purifying and atmosphere-supplying. Air-purifying respirators remove tinaminants from inhaled air, but do not supply oxygen and cannot be used in oxygen deficient atmospheres, or atmospheres considered immediately dangerous to life or health. Atmosphere-supplying respirators exclude ambient air and provide clean air from a separate source. Therefore, atmosphere-supplying respirators can be used in oxygen deficient atmospheres.

The U.S. Centers for Disease Control and Prevention's (CDC) National Institute for Occupational Safety and Health (NIOSH) on 31 May 2002, issued its first approval of respirators for occupational use by emergency responders against chemical, biological, radiological, and nuclear agents. For an up to date list of NIOSH approved respirators, click here.

NIOSH approved Spiromatic Models 9030, 6630, and 4530, manufactured by Interspiro USA Inc., Branford, Conn. The respirators are self-contained breathing apparatus (SCBA) that provide users with air from a pressurized cylinder or tank carried on the back.

The approval signifies that the products are expected to protect fire fighters and other responders from chemical, biological, radiological, and nuclear exposures in the line of duty. NIOSH based its determination on positive results from rigorous laboratory tests, evaluation of product specifications for the devices, and assessment of the manufacturer's quality control procedures.

The action allows the manufacturer to label the approved devices as NIOSH-certified for occupational use by emergency responders. It does not constitute a commercial endorsement of the products.

NIOSH tested and evaluated the devices under criteria announced in December 2001 for certifying SCBAs for occupational use by first responders against chemical, biological, radiological, and nuclear agents. The criteria built on NIOSH's existing program for certifying respirators for occupational use in traditional workplace settings such as factories, construction sites, and health care facilities. Development of the new program involved broad national support and collaboration by many agencies, organizations, and stakeholders.

NIOSH is continuing to test and evaluate other SCBAs submitted by manufacturers for certification under the new program. It also is developing similar criteria for approving other types of respirators, such as air-purifying devices, for use by emergency responders.

Types of Respirators

• Particulate Respirators:These respirators remove small particles from the air you breathe. There are several types of particulate respirators (HEPA, N, P or R series) that are available for use. Some are made without exhalation valves, making them particularly useful in certain health-care settings. Particulate respirators with an exhalation valve should not be used when working in a sterile field, such as an operating room. The exhalation valve allows droplets and particles exhaled by the health care worker to escape and potentially contaminate the surgical field.Particulate respirators are light weight and do not restrict mobility and they are low cost (compared to other respirators). However, this respirator is a negative-pressure device using the suction produced by inhalation to draw air through the filter. The inhalation process, under the best of circumstances, will allow some contaminated air to leak into the facepiece. Communication can be difficult and models with a full facepiece may fog up during use.



• Powered Air-Purifying Respirators (PAPR)A PAPR uses a blower to pass contaminated air through a HEPA filter, which removes the contaminant and supplies purified air to a facepiece, hood or helmet. PAPRs should be used when disposable and reusable half-masks do not provide adequate protection. Better respirators include half- and full-face negative pressure respirators, PAPRs, or positive-pressure airline half-mask respirators. Since this type of respirator exhausts air contaminated by the user, it should not be worn during sterile procedures. Hoods, helmets, and facepiece exhalation valves allow droplets and particles to escape, potentially spreading any contagious particles to the surgical field by the health care worker. This type of respirator usually provides better protection than the other types already mentioned. The PAPR is easier to breathe through, more comfortable, and enough air is delivered to the facepiece, hood or helmet that leakage is usually outward. However, A PAPR can be bulky, noisy, depends on a battery for operation, and is not a true positive pressure device (may allow leakage into hood, helmet, or facepiece) and communication can be difficult.



• Positive-Pressure Supplied-Air RespiratorSupplied-air respirators use compressed air from a stationary source delivered through a hose under pressure to a half-mask or full facepiece. This type of respirator should be used when disposable, reusable respirators, or PAPRs do not provide adequate protection. Since this type of respirator exhausts air contaminated by the user it should not be worn during sterile procedures. The exhalation valve allows droplets and particles to escape through the valve, potentially spreading any contagious particles to the surgical field by the health care worker. The supplied-air respirator is much more protective because it provides a positive pressure in the facepiece and almost all leakage is outward. However, A source of breathing air is needed and the airline hose may limit movement and communication can be difficult.