During voluntary use of disposable N95 and KN95 masks that cannot be washed, one may choose to extend the useful life of the masks by setting up a “rotation of use system”. This method can allow for the use of these masks up to five times before having to dispose of them.
Keeping track of when a mask was last used and safely storing it for at least five days before using it again can allow a reduction of potentially infectious biological contaminants. This method is effective against the virus that causes COVID-191 but is not necessarily effective against all infectious microorganisms you could encounter.
This method is adapted from an emergency use authorization to conserve respiratory protection materials for healthcare workers.2 Though this method is no longer recommended for healthcare workers because of increased N95 availability, it can be used for voluntary personal use of disposable N95 and KN95 masks.
Rotation Method Steps
Step 1: Designate
Designate one mask for each day of the week that you need to wear one. (Example five masks for a full work week). Label each mask and keep track of the number of uses.
Step 2: Decontaminate
After a single day’s use, place the mask in a clean, dry area where it can sit for at least five days.
- Only handle the mask by the straps; avoid touching the facepiece.
- Hang the mask on a hook where it won’t be disturbed or place it in an open paper bag on a shelf. (Lunch-bag size is a good fit).
- Wash your hands after handling a mask that has just been worn.
Step 3: Re-Use
When ready to use the mask again (after at least five days) check the following list. If ANY of the conditions are present, dispose of the mask and replace it with a new one for that day of the week.
Dispose of a mask if:
- The mask has already been worn five times.
- There is any soiling or damage to the materials.
- The ear or head straps have become poorly-connected, overstretched, or have lost elasticity.
- The mask no longer has a snug fit against the face and or gaps appear.
- The mask seems harder to breathe through than it previously was
- The rotation option is not recommended for surgical style masks due to lower quality construction that may be weakened after one use.
- No chemical or UV decontamination methods of any masks are recommended unless the mask manufacturer has provided written instructions.
- van Doremalen N., Bushmaker T., Morris D.H. Aerosol and surface stability of sars-cov-2 as compared with SARS-CoV-1. N Engl J Med. 2020;382:1564–1567.
- FDA In Brief: FDA Revokes Emergency Use Authorizations for Certain Respirators and Decontamination Systems as Access to N95s Increases Nationwide.