PM 2.5 Filter Masks – 11 Things You Need to Know Before Buying

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Even though the air we breathe is invisible to the naked eye, it still carries allergens, germs, chemicals, smoke, bacteria, viruses, and other small particles.

We breathe all of that and it can directly affect our health. That is why modern-day problems require modern-day solutions; filter masks. With the spread and development of the COVID-19 pandemic, the use of filter masks has skyrocketed, even though people are still relatively uninformed about these masks and the reasons they’re used.

That is why in the following paragraphs we’re going to take a look at some FAQs about PM 2.5 filter masks and try to inform our readers as much as currently possible.

PM 2.5 Filter Masks: Quick Summary

  • PM 2.5 – fine particulate matter up to 2.5 µm in size
  • PM 2.5 filter mask – a cloth pocket with replaceable activated carbon filter inserts
  • Filtration efficiency of a PM 2.5 mask yet to be discussed (not enough research)
  • Some PM 2.5 masks marketed as highly-efficient, but don’t achieve the claimed exposure reduction
  • Even best-performing masks can enable particulate transmission due to ill-fitting design
  • PM 2.5 filter masks DO NOT protect against COVID-19 (We still recommend N95 or KN95 )
  • Filter mask certifications and regulations may not be applicable to all environmental occurrences and situations
  • PM 2.5 filter masks may be used as a general protection measure against COVID-19 alongside other measures
  • You can get filters from sites like Honest PPE Supply (great place for KN95 Masks, Face Shields, & PPE Supplies, incredible customer service), you can also check Question #11 for more options)

1. What Does PM 2.5 Stand For?

PM 2.5 stands for the term ‘fine particulate matter’ and represents air pollutant particles that are up to 2.5 µm in size and composition (Aerosol Aerodynamic Diameter is less than 2.5 µm).

These can be liquid or solid particles that can be fine and ultrafine. PM 2.5 particles occur in cases of burning fuel, automobile exhaust, burning of garbage and landfill, processing and melting of metals, as well as chemical reactions that occur in the atmosphere.

They are also the primary contributors to the creation of smog, which has become an increasingly hazardous problem in hundreds of cities around the world.

PM 2.5 particles include sulfates, nitrates, ammonia, carbon monoxide, and many other heavy metal particles that can be hazardous to our overall health.

When inhaled, these particles can travel to the lungs and other organs, causing most commonly heart and lung disease. These particles can cause harm to anyone, but children and the elderly are most sensitive to the effect of PM 2.5 particles.

Also, they are more likely to cause harm to people with an impaired immune system, alcohol users, smokers, and generally people who lead a less healthy lifestyle.

Comparison Particulate matter vs virus
Masks For Heroes

2. What Is A PM 2.5 Filter Mask?

PM 2.5 filter mask is a mask that features a cloth pocket with replaceable activated carbon filter inserts. The mask can sometimes be made from thin foam and feature a vent system for easier breathing (some provide better inhaling and others provide a better exhaling system) and better isolation of the nose and mouth from the particles.

The mask allegedly helps dissipate your breath nicely and shouldn’t cause breathing troubles, irritation of nose, throat, or even eyes.

There isn’t usually a problem with condensation, so people don’t have a problem wearing a PM 2.5 filter mask with glasses.

These masks often come with filters that feature activated carbon or activated bamboo pulp to prevent the particles from entering your airway.

Some masks come with adjustable ear straps, while other, high-quality PM 2.5 masks come with straps that go behind the neck to ensure better fitting and tightness where it is needed the most (around the nose and the chin).

These masks can be used without the PM 2.5 filter because they often feature several layers of protective cotton that can be effective for general use.

Pm 2.5 mask
Source: Masks For Heroes

3. What Does A PM 2.5 Filter Mask Protect You From?

A PM 2.5 filter mask should protect you from overall exposure to air pollution.

But, this only stands true in cases where the mask fits perfectly and is made from high-quality materials (features protective cotton layers and filters).

Nevertheless, the idea is that the mask should protect you from automobile exhaust, smog, smoke, mist, chemicals in the air (or in case you’re working with chemical sprays, for example), and similar occurrences and situations.

However, it is important to mention that there is NOT ENOUGH research conducted regarding the actual protective use and purpose of the PM 2.5 mask in order for us to actually list out every single thing the mask should and could protect you from.

4. What Are PM 2.5 Filter Masks Made From?

The PM 2.5 masks are generally made from cotton, while some brands even feature thin layers of foam to ensure a better fitting and easier breathing.

The masks usually feature several layers of non-woven protective cotton fabric. They also feature adjustable, stretchy ear straps, or additional straps that go behind the neck.

On the other hand, the PM 2.5 filters are usually made from activated carbon. The filters are made to have a lifespan of 1 to 3 days, while some companies claim to have filters that could last for several months, or be reusable in general.

layers of PM 2.5 layers
Masks For Heroes

5. How Long Can You Use A PM 2.5 Filter Mask?

It is stated that PM 2.5 filter masks are disposable.

Usually, the masks come with approximately 5 filters, that can be effective for 1 to 3 days, which could amount to 1 to 2 weeks of occasional use.

It is also stated that filters can be changed once every week, so a mask should be lasting you for a month or two, depending on the frequency of use.

6. Are PM 2.5 Masks Efficient?

study from NIH conducted in Beijing regarding PM 2.5 filter masks’ effectiveness has shown the following results;

  • Out of 9 PM 2.5 masks (made according to international standards) 2 masks were NOT effective because of their poorly fitting. In the majority of the masks, the reusable cloth was loose, and the filters did not cover the whole surface area of the mask.
  • The best performing mask has 2.3% of leakage, while the poorest performing mask has 61% of leakage. This means that the majority of automobile exhaust and pollution occurring at the time of study in Beijing could be inhaled despite the use of PM 2.5 mask. The best performing masks were scarce among volunteers, due to price and availability.
  • There is a great variation in respiratory protection efficiency among PM 2.5 masks (that were used in the study) which further shows that they cannot be reliable as a general protective concept for larger masses and a variety of protective use.
  • Compared to homemade PM 2.5 masks, PM 2.5 filter masks have shown good performance overall, but the PM 2.5 filter masks haven’t shown effectiveness when it comes to particles smaller than 1 µm.
  • Because the standards and guidelines for ‘daily protective masks’ change frequently, some of the masks in the study did not meet the safety standards, but 6 out of 9 masks were in fact certified according to international standards, and yet performed poorly.
  • The majority of volunteers have complained about the masks not fitting properly. The poor facial fit further diminished the protective effectiveness and primary use of the PM 2.5 filter masks.

The study was based on real-life environmental situations, where air pollution and automobile exhaust is a common and regular thing.

In China, millions of people live in urban areas, and some of the cities are the most polluted ones in the world. That is why this study is very important when discussing the efficiency of PM 2.5 masks.

The general conclusion is that the PM 2.5 mask cannot protect you from particles smaller than 1 µm and that the design of the mask plays a rather big role when it comes to its protective efficiency.

7. Can A PM 2.5 Filter Mask Protect From COVID-19, Coronavirus?

There isn’t evidence that a PM 2.5 filter mask can protect you from COVID-19.

What we can say is that the findings have shown the coronavirus (SARS-CoV-2) to be much smaller than PM 2.5 fine particles. In fact, it is believed that coronavirus is only 1/25 of PM 2.5, and definitely smaller than bacteria.

The PM 2.5 masks were not created with bacteria and virus protection in mind, that is safe to say.

However, the use of protective masks is advised as a general precautionary measure by doctors, experts, and epidemiologists.

Alongside the mask, the protective measures against COVID-19 include general hygiene, regular hand washing, social and physical distancing, avoiding larger groups of people, avoiding hugging/kissing, coughing and sneezing in public, etc.

8. Does WHO Recommend PM 2.5 Filter Masks?

The WHO has issued new guidance recommendations to the general public, stating that individuals should wear cloth masks made from at least three layers of fabric.

To be more precise, masks are being recommended to the general public for the reasons of source control (for people who may be infectious, where a mask can reduce the chances of people infecting others).

Now, PM 2.5 masks generally feature several layers of protective cotton fabric, but not every mask has the same features.

Some PM 2.5 masks are simple pieces of cloth, which is definitely not in line with the WHO guidance recommendations.

So, you can use a PM 2.5 mask according to these guidelines only if it has several layers and a filter could also be of good use.

However, there isn’t enough research showing that wearing a PM 2.5 mask will completely protect you from coronavirus, or any virus for that matter.

It might only reduce the chances of getting infected or infecting other people.


Wearing a mask is better than not wearing a mask! Sure, maybe PM 2.5 masks may not protect you from coronavirus, but they can lower your chances of getting infected, or lower the chances of you infecting someone else.

Make sure to follow the recommendations of the WHO, regarding wearing a mask, as well as other safety measures (like social and physical distancing, frequent handwashing with soap or alcohol-based sanitizer, avoiding larger groups of people, etc.).

9. Can A PM 2.5 Mask Be Harmful?

Even though masks are made to protect you from particles that can cause harm to your health, the masks themselves seem to have ill health effects as well.

It has been seen that anti-pollution masks like PM 2.5 cause numerous adverse effects like breathing difficulties, eye irritation, dryness of the nose and mouth, throat infections, feeling of claustrophobia, as well as numerous psychological effects.

Wearing a mask for too long can result in oxygen shortage, respiration trouble, and even heart attacks, as stated by Dr. D. Saha, a scientist, and director at the Central Pollution Control Board in India.

Moreover, the moisture from exhalation inside the mask can create a perfect environment for virus and bacteria growth.

This can result in diseases like influenza, and other microbe-related infections and inflammations in the body.

Not to mention the fact that many of the masks produced, for example in the US bear a warning that ‘misuse may result in sickness or death’, while not explaining what really falls under the umbrella term of ‘misuse’.

10. So, Do PM 2.5 Masks Work?

Even though lack of research and current evidence doesn’t really go in favor of anti-pollution masks like PM 2.5 filter masks, we still believe that they can be useful.

They surely lower your risk of particulates, bacteria, and virus exposure and are recommended by the WHO as a measure recommendation against COVID-19, along with other types of masks and measure guidelines.

However, we cannot say with 100% certainty that PM 2.5 masks work, due to the lack of experiment-based data. So, it is up to people to decide whether they’ll use such a mask and for what purpose, since a definite conclusion about these masks and their use/purpose/effectiveness isn’t really available at the moment.

11. Where Can I Buy PM 2.5 Filter Masks Or Filters?

  • Silvadur reusable mask – This antibacterial fabric mask is a good choice for light daily use. Coated with virucidal silver ions, the mask can reduce the infectivity of the coronavirus. What’s best is that it maintains a meaningful virucidal effect after 50 washes. It’s adjustable ear loops mean that you can always find a comfortable fit that also keeps enough tensile force.
  • Ministry Of Supply – here you can buy custom-fit replacement filter inserts, that are made in accordance with CDC recommendations for consumer purchase. The filter inserts are designed to go together with the 3D Print-Knit Mask, which has been tested by Nelson Labs using the ASTM filtration standards.
  • Leche – here you can buy masks made from polyurethane foam. These masks are washable and reusable. These are not intended for medical use but can be used for daily protection against pollution, pollen, dust, etc.
  • Steve Madden – here you can buy stylish looking masks and PM 2.5 filters (pack of 20  pieces). The layered, stylish masks are sold separately from the filters, so you will have to purchase both individually. The masks can be used on their own, while the filter can’t.
  • OUBA Professional PM 2.5 Filter – these filters can be used with standard cloth masks since they are replaceable, 5-layer activated carbon filters. These are one of the best-selling PM 2.5 filters on Amazon, as they have a great price as well as quality.
  • VIDA & Co – here you can buy the PM 2.5 protective filter masks. It is important to notice that these masks have 2 layers of cotton fabric, and the PM 2.5 filter has 2 layers of melt-blown filter and 1 layer of carbon activated fabric. These masks are not FDA approved but can be suitable for daily use against pollution, dust, pollen, etc. The filter in these masks should be replaced every 7 days.
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10 thoughts on “PM 2.5 Filter Masks – 11 Things You Need to Know Before Buying”

  1. I need to know which way round to fit the filter into the mask. Should the PM2.5 stamp be facing towards the face or away from the face of the wearer?

    • Assuming you are using one of the 5 layer filters, the manufacturers recommend installing the filter with the PM 2.5 label pointing away from the face and into the mask.

      • Thank you much, since I have been having to search to know,. this helps, and but also it’s a little confusing to me that you added the words “into the mask”. I also thought that pM 2.5 filters All have 5 layers.. are some less? The person originally asking said “PM 2.5”..

    • I believe the filters are identical from either side in that the activated carbon layer is sandwiched in the middle between layers of fabric.

      • Can pm2.5 mask filters be cut to size? I’m trying to find some filters to fit inside the masks I already bought for my kids. It’s actually kind of frustrating because I searched and searched for a mask that would work the best for school for them. I wanted one that has straps that go up over their heads so their ears don’t get sore and can also be pulled down to sit around their necks when they don’t need them covering their face. One of my sons is also very conscientious of thicker masks making it feel difficult for him to breathe so I wanted one that would be a thinner material but also have a place to put a filter so that it was still effective enough. I finally found some that fit all the things I was looking for and bought them. I’m not sure if I’m allowed to say the brand name on here or not so I won’t unless asked. Anyway, they finally came in the mail and they do work really great other than the filters. The filters are super thin and flimsy and slide around inside the mask pocket as they wear them which causes them to bunch up which completely defeats the purpose of them. I have been putting a small piece of painters tape around the filter to get it to stay in place until I can figure out what to do. The tape fits around the edges of the pocket in the mask so it doesn’t block the filter from their nose and mouth but it is tricky to get it to work. I really don’t want to buy new masks as I’ve already spend a fair amount of money on those ones. I’d really just like to find some thicker or stiffer filters that will stay put as they wear them. This article was very informative and I was thinking I might be able to get some good suggestions or ideas from here. Any would be greatly appreciated!

        • I know this comment is old but I wanted to recommend Filti filters. I have been using this fabric since April. In the beginning I had to buy it in big sheets and manually cut it into filters but now they sell filters already cut to size. There has been some laboratory testing carried out on their product, the results are linked on their webpage, that showed filtration down to .3 so it filters more than the 2.5 filters do. Another advantage is they are not thick or bulky at all and the filters can be cut even smaller if you need to. They are a bit more expensive, and are sold only in bundles of 20, but may be something you want to check out if you are still in the market for filters.

  2. This was a very useful information about the pm2.5 mask. Because I used one today and I could not feel comfortable and felt like I was claustrophobic. I was waiting inside a doctor office and I had to keep breathing to feel less claustrophobic . I will recommend this only for very short periods of use .


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