N95 respirators are a version of filtering facepiece respirators (FFR) worn by frontline health staff responding to the coronavirus and it is critical that they are prioritised for health care workers. N95 respirators fit closely to a person’s face and are very efficient at filtering small airborne particles such as this COVID-19 strain of coronavirus. In fact, N95 respirators are rated to filter out 95% of airborne particles (standard NIOSH 42 CFR Part 84). Prior to use, N95 respirators require a special fitting procedure to ensure they are effective. Due to their special fit requirements, N95 respirators cannot be used by children or persons with facial hair. If your organisation is purchasing N95 or other FFRs for use in health care settings it is important to make sure that these are produced to required standards and that you are aware of the performance characteristics of the product (i.e. how well the respirator filters out particles of a certain size range, or ‘filtration efficiency’). Typically, the higher (or better) the filtration efficiency, the more protective the respirator should be against SARS-CoV-2. A list of FFRs approved for use by the CDC is available here and an infographic outlining required labeling of CDC approved FFRs is available here. Some FFRs come with an exhalation valve. This is a small plastic device that can be seen on the outside of the respirator. This exhalation valve makes breathing more comfortable while wearing the respirator. The one-way valve means that the respirator allows exhalation of respiratory particles and will therefore be less effective in limiting onward transmission of SARS-CoV-2. The CDC recommends that N95 respirators with exhalation valves should not be used in health care settings and the European Centre for Disease Prevention and Control have made similar recommendations for them not to be used in communities either. N95 respirators are typically designated for ‘one time use’ only, however, global shortages have resulted in renewed interest in the safe decontamination of N95 respirators. A summary of decontamination procedures can be found in the annex of this WHO document on the rational use of personal protective equipment.

Who should wear a N95 respirator?

The use of FFRs or N95 respirators by the general public is not recommended. These respirators must be reserved for use by healthcare workers and require special fitting procedures to be effective. WHO guidance on the use of respirators and masks in the context of COVID-19 is available here.

Want to learn more about mask use for interrupting the spread of COVID-19?

Editor's note

Author: Jackie Knee
Review: Peter Winch, Julie Watson
Last update: 06.18.2020

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