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NIOSH Respiratory Diseases Research Program

Evidence Package for the National Academies' Review 2006-2007

11.1 Respirator Approval Program

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NIOSH is mandated by Congress to approve or certify respirators in accordance with the minimum requirements outlined in 42 CFR Part 84, 1996. 42 CFR Part 84 requires that respirators submitted for evaluation against the terms of the standard must be accompanied by data that demonstrate the respirator under evaluation meets or exceeds the performance requirements set forth therein. Once approved, the quality assurance requirements specified in Subpart E of the standard require an ongoing effort by the approval holder for the purpose of assuring not only the material aspects, but the performance level of the approved product.  

Particulate filter respirators protect against airborne particulate matter such as dusts, fibers, mists, fumes, and smokes. There are three styles of particulate respirators in use:  quarter masks, half-masks (filtering facepiece or elastomeric), and full facepieces.   Particulate respirators are the simplest, least expensive, and least protective respirator types available. They do not protect against chemicals, gases, or vaports and are intended only for low hazard levels.

Gas/Vapor respirators are APRs designed to keep harmful particles, gases, and/or vapors from a user’s breathing zone and to remove contaminants from breathed air.

Gas masks are also known as “air-purifying respirators” because they filter or clean chemical gases and possibly particles out of the air breathed. This respirator includes a facepiece or mask, and a filter/cartridge (if the filter is in a metal shell it is called a “canister”). Straps secure the facepiece to the head. The cartridge may have a filter to remove particles (such as a biological weapon), charcoal (to remove certain chemicals), both, or other parts. When the user inhales, air is pulled through the filter.

PAPRs may have a tight-fitting facepiece or a loose-fitting head covering connected by a breathing hose to a battery/blower/cartridge unit. 

SCBA is the respirator commonly used by firefighters. These use their own air tank to supply clean air, so filters are not necessary. They protect against high concentrations of dangerous chemicals; however, they are very heavy and require very special training to use and maintain them. Also, the air tanks typically last an hour or less depending upon their rating and how hard the user is breathing.


Respirators are certified in accordance with the minimum requirements outlined in 42 CFR Part 84, 1996. Respirators are processed in a first in first out mode of operation within 90 days. The test procedures used to certify respirators are available on the NIOSH Web site.


As of May 2006, 5479 respirator approvals have been issued by NIOSH since tracking these approvals in 1995. Table 9 provides a breakdown of the types of respirator approvals issued. Respirator approvals by respirator type since 1995:

Respirator approvals by respirator type since 1995

218 SCUB
98 Gas Mask
122 Airline
674 Chemical cartridge (Gas/Vapor)
4279 Particulate
5479 Total between 1995 and 2006 (May)

Table 9

Test procedures used to conduct the tests for approving respirators are available at

The Standard Application for the Approval of Respirators is available in downloadable form at

The Certified Equipment List

 Since the Certified Equipment List was released in printed copy on September 30, 1993, NIOSH has received numerous comments on the publication. NIOSH commissioned a survey of users and partners (including manufacturers, labor unions, safety directors, industrial hygienists, enforcement personnel, and others) to determine the best format for this document and essential information required on each device listed.

Several changes were made to the format based upon the survey results. These modifications include discontinuing abbreviations and acronyms. The model information returns as the Product Trade Name so that users can readily identify certified products from packaging and advertising brochures. An address, contact person, and phone number are provided for each approval-holding manufacturer. Hose length and pressure range information for supplied air respirators is still eliminated out of concern that the user may rely solely upon the Certified Equipment List instead of the Users Instruction Manual for this critical information. Because of modifications made from time to time by the respirator manufacturer, all respirators with the same certification number may not have the same pressure requirements and hose length options. Currently, the only accurate source for this information is the NIOSH approval label on older models and Users Instruction Manuals.

Since 1993, the Certified Equipment List has added over 5,100 approved devices so that the total list now includes over 7,100 products. Because of the document size and low utilization in the printed form, NIOSH is making this list available in electronic format.   The CEL may be accessed at:

NIOSH issues User Notices to inform users of a condition or risk that may exist with a NIOSH-certified product. User Notices are posted at: NIOSH issued user notices as well as third party notices are posted as NIOSH becomes aware of the issues. An archive of user notices issued dates back to 1995.

Intermediate Outcomes

NIOSH reclassification of filters available to the worker as specified in 42 CFR  84 improved the ability of respirator program administrators to select the appropriate respirator to address their hazards. Workers are protected from respiratory hazards because of the availability of a wide range of respiratory protective equipment.

What’s Ahead

In 2004, NIOSH initiated a Total Inward Leakage (TIL) benchmark testing program to evaluate the leakage around the respirator face-seal to identify potential requirements for incorporation of particulate respirator testing in an effort to improve respirator design and fit. TIL is expected to strengthen the scientific basis on which NIOSH recommendations for respiratory protection depend. An important impetus for the TIL program was the RDRP need for filtering facepiece respirators with better inherent fitting characteristics for protecting emergency responders and healthcare workers from airborne infectious agents. A broad range of governmental and nongovernmental external experts and stakeholders will participate in TIL standards development and incorporation of TIL into the respirator approval process.