Editing Respirator (section)

== Respirator selection ==<!-- This section is linked from [[Personal protective equipment]] EDIT: section title renamed-->
Air-purifying respirators are respirators that draw in the surrounding air and purify it before it is breathed (unlike air-supplying respirators, which are sealed systems, with no air intake, like those used underwater). Air-purifying respirators ''filter'' particulates, gases, and vapors from the air, and may be [[Pressure#Negative pressures|negative-pressure]] respirators driven by the wearer's inhalation and exhalation, or [[positive pressure|positive-pressure]] units such as [[powered air-purifying respirator]]s (PAPRs).

According to the NIOSH Respirator Selection Logic, air-purifying respirators are recommended for concentrations of hazardous particulates or gases that are greater than the relevant [[occupational exposure limit]] but less than the [[immediately dangerous to life or health]] level and the manufacturer's maximum use concentration, subject to the respirator having a sufficient [[Respirator assigned protection factors|assigned protection factor]]. For substances hazardous to the eyes, a respirator equipped with a full facepiece, helmet, or hood is recommended.  Air-purifying respirators are not effective during [[firefighting]], in [[oxygen-deficient atmosphere]], or in an unknown atmosphere; in these situations a [[#Self-contained breathing apparatus|self-contained breathing apparatus]] is recommended instead.<ref name=":8">{{Cite journal|title=NIOSH respirator selection logic|url=https://www.cdc.gov/niosh/docs/2005-100/default.html|last=Bollinger|first=Nancy|date=2004-10-01|website=U.S. National Institute for Occupational Safety and Health|pages=5–16|language=en-us|doi=10.26616/NIOSHPUB2005100|access-date=2020-04-20|doi-access=free|archive-date=15 July 2020|archive-url=https://web.archive.org/web/20200715045859/https://www.cdc.gov/niosh/docs/2005-100/default.html|url-status=live}}</ref>