1.1 This practice sets forth minimally accepted practices for occupational respirator use; provides information and guidance on the proper selection, use, and maintenance of respirators; and contains requirements for establishing, implementing, and evaluating respirator programs. 1.2 This practice covers the use of respirators to protect persons against the inhalation of harmful air contaminants and oxygen-deficient atmospheres in the workplace. The following are not covered by this practice: 1.2.1 Underwater breathing devices, 1.2.2 Aircraft oxygen systems, 1.2.3 Supplied-air suits, 1.2.4 Use of respirators under military combat conditions, and 1.2.5 Medical inhalators and resuscitators. 1.3 Units—The values stated in inch-pound units are to be regarded as the standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard. 1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use. 1.5 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.