A NIOSH approved respirator is a protective device designed to protect workers from airborne contaminants in breathing air sources. NIOSH is the National Institute for Occupational Safety and Health, a division of the U.S. Centers for Disease Control and Prevention. A NIOSH approved respirator may be of the type that removes contaminants from outside air or it may supply breathing air from a clean source. Approved equipment is classified based on the situation in which it will be used, the length of time for which it functions, and the type of respiratory hazard it is designed to correct. Respirators are approved by NIOSH under the standards set forth in Title 42, Part 84, of the U.S. Code of Federal Regulations.
Respirators are designed for two primary applications — those that filter or clean outside air in situations that are not life-threatening and those that supply clean air from an alternate source. Non-powered respirators include those with a filter medium that removes particulate contamination such as dust or mist and those with a chemical cartridge that removes or neutralizes specific gases or vapors. A gas mask is a non-powered unit containing a facepiece and canister or cartridge for removal of gases such as carbon monoxide and ammonia fumes.
Powered units include supplied-air respirators, i.e., those which provide air from an outside source and are connected to the wearer with a hose and harness system. Supplied-air systems can be designed to provide air only from a clean air source through a blower or may allow for the entrance of ambient air if the blower is not operating. A self-contained breathing apparatus supplies clean air only from a separate source, usually a portable pressurized tank. These units may be open-circuit, where exhaled air vents to the outside, or closed-circuit, where exhaled air is recaptured and recycled through the unit. Self-contained breathing apparatus is used in situations where the ambient air presents a hazardous and potentially life-threatening atmosphere.
The designation for a NIOSH approved respirator may be for entry into and escape from a potentially hazardous atmosphere or for escape only. Respirators are classified for use against oxygen deficiency, gases and vapors, or particulates. Units may be approved for various prescribed service times, from three minutes to four hours; other time frames may be specified by NIOSH.
A respirator may be submitted for approval by NIOSH with a written application to the Certification and Quality Assurance Branch. The application must include a detailed description of the respirator accompanied by drawings and specifications, construction details and materials used, a statement that the respirator has been pretested for compliance including test results, and a quality control plan to assure consistent manufacturing standards. NIOSH will request a particular number of representative units from the manufacturer for inspection, examination, and testing. A NIOSH approved respirator is one that has successfully passed the entire testing phase.