Set of 2 Refills- Five layer activated carbon charcoal fill. The mask itself is machine washable and should last years.
The filters are 5 layers with activated carbon. I would change these out using your judgement for standards of personal hygiene. The Activated Carbon filter is a very important filter in purifier systems, but it can only last for a short time. Typical Activated carbon filter can only last between two and four weeks, then you need to launder before using it again. The Activated Carbon filter needs to be changed every few month to be efficient. This is because of the adsorption process that increasingly fill up the pollutants inside the activated carbon bed. Once the bed is saturated, the filter can no longer be capable of taking in more pollutants.
Can Activated Carbon be reused? The simple answer is yes, because of the porous nature of activated carbon. However, you can only reuse the Activated Carbon filter two to the maximum of three times, then you must replace the carbon filter so it can work against the smoke, odors and chemicals.
How to clean my filter:
If you have a sanitizer setting on your laundry machine use that. If not, Soak the filter in hot (just short of boiling water) in a pot of water on the stove for 3 minutes. Then toss in the laundry machine. DO NOT use fabric softener! Discard if used.
Machine dry on low heat and then set in direct sunlight for 2-3 hours before use. -NO GUARANTEES or testing REGARDING COVID-19.