How Long Do PM2.5 Filters for Face Masks Last? Your Burning Filter Questions Answered

Living through wildfires and a pandemic, face masks are definitely here to stay, and more of us want to know: how do we get the best protection possible in these new times, while making sure we’re not taking away available supply for those working in high risk, front-line occupations? 

Cloth face masks with a PM2.5 filter are an excellent alternative for the general public’s protection from these elements. When you use a PM2.5 filter fitted for your mask, you can benefit from better protection than going without. Not only that, but you’ll also feel the extra assurance that you’re not inhaling PM2.5 particulate matter, which can have devastating health consequences. 

But we get it –– PM2.5 filters add an extra expense on top of everything else. You might be wondering, how long do these filters last, and can you clean them? Read on for a quick guide to help you understand how to maximize PM2.5 filter benefits. 

So what exactly is a PM2.5 filter? 

In short, a PM2.5 filter is designed to filter airborne particulate matter less than 2.5 microns in size. These can be liquid or solid particles, fine or ultrafine. These particles are released from burning fuel, vehicle exhaust, metals melting and processing, and atmospheric chemical reactions. 

Those of us living in wildfire vulnerable areas might hear more about PM2.5 particles, as the burning produces much of it, harming our health. 

PM2.5 filters consist of five layers of both activated carbon filter and a variety of fabric types, with each layer serving a specific protection purpose: 

• Layers 1 and 5: made of spun-bound polyester, filters out large particles ● Middle layer: activated carbon; traps particulate matter 
• Layers 2 and 4: made of high-efficiency melt-blown polypropylene, which filters small substances. 

How long do PM2.5 filters last? 

Ah, the big question. The bottom line is that the longevity of a PM2.5 filter depends on how much you use it and the environment you use it in.

For example, if you live in a super polluted city or area that is prone to wildfires, you’re more susceptible to high levels of particulate matter. Wearing a reusable face mask containing a PM2.5 filter in these settings, you will likely need to replace your filter after just a few uses. 

Debrief Me® PM2.5 filters should last 20-30 hours if you’re exposed to heavy smoke, grain bins, off-road construction or demolition environments regularly; 30-40 hours if exposed to light smoke or dust; and 50-60 hours if you use the filter for protection against allergens, pollutants and odors, for example. 

When they reach their full capacity, PM2.5 filters will become saturated and lose their effectiveness in trapping air pollutants. It’s important to keep this in mind when buying, as manufacturers’ prescribed usage period for your filters will vary. 

Can you clean PM2.5 filters? 

Unfortunately, we’ve got some bad news: you can’t wash out particles from the activated carbon layer. For that reason, washing PM2.5 filters isn’t advisable for both after recommended use and in between uses. 

PM2.5 filters consist of specifically designed layers, as we’ve mentioned above, that enhance adsorption of particles. When these layers are exposed to liquids, this functionality is eliminated, essentially rendering the filter ineffective. 

We do, however, highly recommend washing your reusable cloth face mask with hot water and soap after use. Just refrain from washing the filter itself! Here’s some ways you can tell your filter may need to be replaced: 

• You experience more difficult breathing 
• The filter is discolored (typically when saturated, the filter turns grey) 
• There are tears and folds in the filter (usually caused by moisture and deformation from repeated use) 

Where can I buy PM2.5 filters for my face mask? 

To ensure you’re getting the most protection out of your PM2.5 filter, here’s some pointers to remember while you’re shopping: 

• Watch out for counterfeit/false filters. With so many face mask options on the market today, there are lots of claims made by brands that simply aren’t true. Filters can come super cheaply, but their effectiveness can be substandard, saturating very quickly. Filters

that are backed by third-party lab tests on filtration efficiency, like Debrief Me®’s, are best. 

• Get filters that fit. Make sure your PM2.5 filter actually fits your particular face mask, as studies have shown that poorly fitting filters significantly decrease filtration efficiency. The best thing to do is to measure out your mask dimensions and compare them to those of the PM2.5 filter you’re looking to buy first. 
• Check prescribed usage. There is no all-or-nothing rule when it comes to PM2.5 filter duration of use. As mentioned above, usage depends on your lifestyle and environments. We recommend checking the manufacturer’s specific usage period for your filters and comparing to other brands’ to best gauge the one that will fit your lifestyle and needs. 

Debrief Me®’s X95 and X99 anti-pollution face masks come fitted with specific PM2.5 carbon activated filters. As we’ve discussed here, the X95 filters will not fit to the X99 masks and vice versa, since the shape and size of each differ. 

For lab-tested, high quality PM2.5 filters, check out Debrief Me®’s selection at https://debriefme.com/collections/filters.