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National Institute for Occupational Safety and Health (NIOSH)

"Determination of Particulate Filter Efficiency Level for N95 Series Filters Against Solid Particulates for Non-Powered, Air-Purifying Respirators Standard Test Procedure (STP)"


This procedure establishes the means for ensuring that the particulate filtering efficiency ofN95 series filters used on non-powered respirators submitted for Approval, Extension of Approval, or examined during Certified Product Audits, meets the minimum certification standards set forth in 42 CFR, Part 84, Subpart K, §84.181. These filters or filter cartridges may be integral to respirator construction; mounted individually, or in sets of up to three; used in conjunction with cartridges and canisters for chin-style, front-mounted, and back-mounted gas masks; or used in combination with gas-and-vapor or atmosphere-supplying respirators.

Standard Type(s)
Test Method

A definitive procedure that produces a test result: Examples of test methods include, but are not limited to: identification, measurement, and evaluation of one or more qualities, characteristics, or properties. A precision and bias statement shall be reported at the end of a test method.

Personal Protective Equipment
Respiratory Protection

A breathing device worn to prevent inhalation of hazardous substances. Respirators protect the user in two basic ways. The first is by the removal of contaminants from the air. Respirators of this type include particulate respirators, which filter out airborne particles; and "gas masks” which filter out chemicals and gases. Other respirators protect by supplying clean respirable air from another source. Respirators that fall into this category include airline respirators, which use compressed air from a remote source; and self-contained breathing apparatus (SCBA), which include their own air supply.

  • Non-Powered Air-Purifying Particulate Respirators
Gas and Vapor
  • Inhalation
The CFRs referenced here are not necessarily the only regulations or standards for which this NIOSH STP can, could or should be used. Follow the “Referenced Standard” link for more information regarding the CFRs to which this STP may apply. Likewise, follow the web link provided for full details about this test method.

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