The longer a face mask is worn, the more particulate matter builds up on the filter, and the more difficult it is for air to flow through the filter material. One sign that a mask should be disposed of is when it becomes more difficult to breathe through. Much like the water tap filter on your kitchen faucet, when the flow of the water stream turns to a dribble, it's well past time to change your water filter.
Debris buildup also poses a problem when attempting to disinfect and reuse masks. All kinds of new strategies are being developed to disinfect N95 masks so that they are reusable during a PPE shortage. Methods are being developed to sterilize the masks, however, the filters are still going to have particulate matter, such as dirt, blood, spit and other human debris on the surface of the mask. This debris clogs up the pores of the filter material. Disinfection is another name for sterilization. These methods will deactivate a virus and kill bacteria, but the filters won't necessarily be cleaned from airflow blockages. The "clean" masks still have a lesser lifespan than that of a new mask.
- July 2020
- May 2020