Editing Respirator (section)

==== Issues with fit testing ====
If respirators ''must'' be used, under 29 CFR 1910.134, OSHA requires respirator users to conduct a [[respirator fit test]], with a safety factor of 10 to offset lower fit during real world use.<ref name="twonine">{{cite web|title=MAJOR REQUIREMENTS OF OSHA'S RESPIRATORY PROTECTION STANDARD 29 CFR 1910.134|url=https://www.osha.gov/sites/default/files/training-library_major_requirements.pdf|publisher=United States Department of Labor, OSHA|access-date=3 June 2024|archive-date=27 January 2024|archive-url=https://web.archive.org/web/20240127222116/https://www.osha.gov/sites/default/files/training-library_major_requirements.pdf|url-status=live}}</ref> However, NIOSH notes the large amount of time required for fit testing has been a point of contention for employers.<ref>{{cite web|url=https://blogs.cdc.gov/niosh-science-blog/2016/01/05/fit-testing/|title=New NIOSH Study Supports the OSHA Annual Fit Testing Requirements for Filtering Facepiece Respirators|publisher=NIOSH|date=5 January 2016|first1=Ziqing|last1=Zhuang|first2=Michael|last2=Bergman|first3=Jaclyn|last3=Krah}}</ref>

Other opinions concern the change in performance of respirators in use compared to when fit testing, and compared to engineering control alternatives:

{{blockquote|The [[Respirators testing in the workplaces|very limited field tests of air-purifying respirator performance in the workplace]] show that respirators may perform far less well under actual use conditions than is indicated by laboratory [[Respirator fit test|fit factors]]. We are not yet able to predict the level of protection accurately; it will vary from person to person, and it may also vary from one use to the next for the same individual. In contrast, [[Hierarchy of hazard controls|we can predict the effectiveness of engineering controls]], and we can monitor their performance with commercially available state-of-the-art devices.<ref name="Hyatt-1984">{{cite journal|author=Edwin C. Hyatt|date=1984|title=Respirators: How well do they really protect?|url=http://www.isrp.com/|journal=Journal of the International Society for Respiratory Protection|volume=2|pages=6–19|issn=0892-6298|access-date=22 January 2018|number=1|archive-date=22 October 2016|archive-url=https://web.archive.org/web/20161022021929/http://www.isrp.com/|url-status=live}}</ref>}}