With climate change becoming an increasingly-present issue, wildfires too are becoming more common worldwide. These terrible events are impacting an increasing number of people globally and are an issue we need to work together to prevent.
There is no denying that we must take collaborative action against climate change and the wildfires and other dangers that come with it. But, unfortunately, in the shorter term, the number of wildfires is increasing, and we must be aware of how we can protect ourselves.
Research has shown that the number of fires in most areas around the U.S has increased significantly since 1984 (1). Further, these fires are not only more common but also larger than they previously were (2). This shows that over the past 30-40 years, wildfires have become more common and more severe and therefore pose a greater threat than ever before.
Although the most obvious danger of wildfires is the rapidly-spreading flames, the threat that impacts significantly more people is smoke. This is because wildfire smoke can contain a wide range of different pollutants in the form of gaseous, coarse and fine particles.
This smoke can reach tens or even hundreds of kilometres from the source and impact millions of people. While the effects are more potent closer to the fire, even those kilometres away can face negative health impacts from inhaling wildfire smoke.
Currently, there are only a very limited number of ways to reduce our exposure to the harmful pollutants contained within this smoke. Of course, the best protection is to physically limit our exposure wherever possible. This means staying inside and moving away from the smoke.
However, it’s often impossible to physically move away from the smoke. If this is the case, an air purifier is the best way to filter pollutants at home or in the car. If you have to go out, a certified mask or respirator is the best, and in many cases, only effective protection.
In this article, we will look at everything you need to know about masks and wildfire smoke. We will first discuss why we need to protect ourselves from wildfire smoke and whether masks are effective against the ultrafine particles within. Finally, we will discuss how to select the right mask and considerations to take into account when using a mask for wildfire smoke protection.
Dangers of Wildfire Smoke
While it’s fine to discuss how we can protect ourselves from wildfire smoke, it’s also worth discussing what exactly we need to protect ourselves from. Wildfire smoke has a range of health implications that can adversely affect people - some more so than others.
Although the most severe effects are felt closer to the source of the fire, even people living at a distance can feel the impacts. As such, it’s essential to check the local AQI before stepping outside - even if you believe that you won’t be affected.
While there’s no broad rule as to when wildfire smoke may be an issue, we would recommend checking the AQI even if there is a wildfire in another state, region or nearby country. Wind can blow harmful particles as far as 3000 miles (1) and this can pose a threat even when we believe we are safe.
The most common impact of wildfire smoke on people is the irritation of our respiratory system. In turn, this can cause an immune response which results in the inflammation of other parts of our bodies.
More severe symptoms include shortness of breath, severe coughing, dizziness, chest pain and heart palpitations. All of these are serious health conditions, and you should seek medical attention promptly if you experience any of them (2).
Areas with extra pollutants due to wildfires have also been found to increase the risk of some infections, including COVID-19. This is because COVID virions can attach to the larger particles in the air caused by the wildfires. While this is a far less common issue, it’s another reason to avoid inhaling smoke particles wherever possible.
The most impacted groups for wildfire smoke tend to be those with respiratory or heart diseases, pregnant women, the elderly, infants and children. If you or anyone close to you falls into any of these categories, ensure that they have protection measures.
We don’t want to scare anyone by discussing the adverse impacts of wildfire smoke on human health, but rather to raise awareness of why we should be considerate about how we prevent our exposure.
Luckily, we can avoid many of these adverse impacts partly or totally by taking simple steps. As we will discuss in this article, masks are the best way to protect yourself when you need to go outside. When inside, try to minimise pollutants using an air purifier.
Can Masks Filter Wildfire Smoke?
Wildfire smoke consists of various pollutants, including gaseous pollutants such as carbon monoxide and hazardous air pollutants such as polycyclic aromatic hydrocarbons, water vapour, and particle pollution (1). Particle pollution is generally considered the particle type that provides the most significant public health threat out of these pollutants.
While standard respirators and masks will not protect against gaseous pollutants, certified and lab-tested devices are capable against the particle pollution that comes with wildfire smoke. These particles are the biggest issue and often lead to smoke-related hospitalisations from wildfires.
Particle diameters for wildfire-related particles can be both coarse and fine. Coarse particles are 2.5µm to 10µm while fine particles sit under 2.5µm in diameter. While both particle sizes are detrimental to health when inhaled, fine particles are the bigger threat.
Interestingly, as we discussed recently in our ‘Masks are not sieves’ article, filters are more capable of filtering out these smaller fine particles than their larger 2.5µm counterparts. Even with wildfire smoke particles reaching mere nanometers in diameter, certified masks such as N95, KN95 and KF94 are effective.
A study showed that against wildfire smoke particles with a number median diameter of 0.1µm, N95 masks provided a protection factor of 16 (2). This means that only 1/16th of the tested particles could penetrate the device. This is a significant decrease in particle exposure and shows how effective masks can be against wildfire smoke.
The same study found that when exposed to wildfire smoke in a real-world situation, wearing a respirator led to a 30% reduction in hospitalisations (for smoke-related admissions) compared to a population not wearing face coverings.
This lab testing and real-world investigation show that certified masks and respirators with high filtration can minimise exposure to and the health effects caused by wildfire smoke.
Monitoring Wildfire Smoke
If you live in a wildfire-prone area such as California or Australia, it’s likely that there is already an extensive network of air quality monitors present. Monitoring the local air conditions and acting accordingly is a vital step toward ensuring that we are protecting our health as best as possible.
If you live in an area that isn’t covered by local monitoring stations, it might be worth investing in an air quality monitor. These devices are becoming more accessible by the day, and it’s possible to find inexpensive portable air quality monitors that provide a good level of accuracy.
Try searching Google for ‘(location) air quality’ to check if your local area has air quality monitors. If monitors are present, you can easily find these on a third-party air quality website or the local/regional government website.
If official monitors are lacking, it might be worth looking for other air quality networks. Purple Air has a network of monitors that can be publicly accessed by anyone, and these monitors are especially common around California.
If neither official monitors nor networks such as Purple Air are present, then you might want to look into purchasing a personal air quality monitor. These small, portable monitors can be taken anywhere and will monitor pollutant levels wherever you go.
While these devices aren’t as accurate as official monitors and more pricey setups such as Purple Air, they provide insights into the air quality and individual pollutant levels. One popular portable device is the AtmoTube Pro, an air quality monitor measuring PM2.5, PM10, VOCs and more.
When Should I Wear a Mask?
AQI from California Air Resource Board
While the AQI system provides a good framework for when certain groups of individuals are at risk, there are no clear guidelines for when a mask should be worn. Unfortunately, this leads to a lot of confusion - with no official guidelines about mask-wearing during wildfires, when should you be wearing a mask?
In the end, it comes down to your own tolerances. Ideally, we would wear masks anytime the AQI surpasses 50. However, with the AQI regularly passing 50 in some areas, this recommendation is too strict for many individuals.
With that being said, as per the U.S EPA AQI, at levels above 100, sensitive children and adults begin to feel the impacts of air pollution. If you have a respiratory condition such as asthma and are part of this group, you will likely want to wear a mask whenever the air quality is above 100.
For non-sensitive groups, the AQI indicates that you will want to wear a mask at pollution levels above 150. At this point, everyone should be wearing a mask as the impacts of air pollution begin to be felt by all age groups and all risk groups.
However, the issue with air pollution, including that from wildfire smoke, is that there isn’t a level where it suddenly becomes harmful. Instead, the impacts of air pollution exist at all levels and are exacerbated as pollutant concentrations increase.
For this reason, deciding when to wear a mask depends on your personal tolerances. We recommend that sensitive groups wear a mask above 100 AQI, and everyone wears a mask at AQIs above 150. However, there is no harm in wearing a mask earlier.
During wildfires, you will likely see AQI levels far more severe than even 150. It’s not uncommon for levels above 300 or even 500 to be seen. In these situations, there is no question - everyone should be wearing masks.
The Importance of Being Prepared
When it comes to wildfires, it is extremely important to be prepared. This means not only having a plan and taking other precautionary measures but also ensuring that you have a supply of masks on hand.
The issue with obtaining masks while wildfires are ongoing is that masks will very quickly sell out locally, and it can be hard to get deliveries in potentially dangerous conditions. As such, the best way to ensure you have masks on hand when needed is to prepare and obtain them in advance.
Depending on the number of people living in your home and the frequency of wildfires in your area, the supply of masks you will want access to varies greatly. However, we recommend having enough masks on hand to last for a couple of weeks if needed.
While most fires won’t last in an area for more than a few days, the effects of wildfire smoke can stay for significantly longer. As wildfire smoke can impact people over 3000 miles away, you may be in a situation where masks are needed for a significant length of time.
It’s also important to remember that masks won't last long in situations where the AQI is as extreme as it often is during wildfires. The lifespan of a mask is impacted by the particles loaded on the filter, and a wildfire will load a filter with particles at an exceptionally fast rate.
This means that you will likely need to replace or clean your masks daily during times of severe wildfire smoke. Disposable masks such as N95 respirators will need to be replaced once they have loaded to the point that breathing becomes difficult.
For masks such as the AirPop Light SE, the mask can be washed and reused multiple times while still retaining a high level of filtration. However, even with a mask such as the Light SE, it’s important to have enough on hand so they can be worn and washed in cycles.
If you are regularly exposed to extremely high levels of particulate pollution, it might be worth considering a device that provides an even higher level of protection, such as a P100 half-face respirator. If purchasing these devices, ensure that you have enough replacement filters to go around and to last a couple of weeks if needed.
For further information regarding masks and respirators for use during wildfires, we recommend reading the CDC fact sheet.
Wildfire Mask Considerations
When it comes to selecting the best mask for wildfires, a few extra considerations need to be kept in mind. We recently published an article discussing factors to consider before purchasing a mask, and we recommend reading that for general purchasing advice.
On top of what was mentioned in that article, factors unique to wildfires need to be considered. Let's dive into what these are.
Lower Mask Lifespan
Due to the extreme particle concentrations that wildfires bring with them, the mask or filters that you purchase will likely perform for far less time than intended. For example, a filter rated to last 50 hours in day to day AQI (50-100) might only last 2-8 hours in the inferior air quality that wildfires bring.
While there is no way to determine precisely when a filter or mask needs replacing, the device's colour and breathability are good indications. For example, if the filter becomes significantly harder to pass air through, it's probably worth replacing it. Further, if the filter becomes visibly discoloured, it will need to be replaced.
A Certified Device is Essential
While cloth and surgical masks have done a fantastic job filling the gaps during COVID and the lack of respirators that followed, these devices should never be used when it comes to wildfires. This is especially true now that many sources officially call the shortage over.
Cloth masks and surgical masks are generally unrated devices intended to catch large respiratory excretions. These devices have never been intended to filter inhaled particles, and they do a poor job. For example, in the same study that showed that N95 respirators had a protection factor of 16, surgical masks had a protection factor of only 1.9. This means that over 50% of particles will penetrate or bypass the surgical mask where only 1/16th can get through the N95 device.
Therefore, while you may have some cloth or surgical masks sitting around due to the pandemic, these should not be used. Instead, look for a device that has an official certification (N95, KN95, KF94 or FFP2) or that has lab testing against fine and ultra-fine particles.
AirPop has been tested against the KN95 standard and adheres to all performance criteria. Further, we have undergone extensive testing from bodies and companies such as BSI, SGS, SQST and more. All of these test results are publicly available on our website.
Masks Will Not Protect Against Gases
While some devices are designed to filter out gaseous pollutants, most are not. Standard masks and respirators such as N95s will not provide protection against these pollutants. Even in the case of gas masks, these are only effective if the fitted filters are designed for the filtration of the gas in question.
While there are many gases emitted near wildfires, these tend to pose less of a threat than particle pollutants. As such, despite not filtering gases, a respirator or certified mask will still provide essential particle protection against wildfires.
Masks Require Readjusting
As we will discuss later in this article, it's vital to fit-check a mask when donned. This will ensure that you receive the best protection possible from the device. However, many people overlook that masks and respirators need to be re-checked regularly. This is especially true when the wearer is doing physical activities.
It's easy for a mask to become dislodged or move slightly over time. While you may not even notice that the device has moved, these slight movements can break the seal and lead to leakage. This, in turn, can limit the protection that the device can provide.
With this in mind, it's essential to re-check your mask's seal regularly. Make sure to perform fit-tests after physical activities or even during. While we have been told not to touch our masks when used for COVID-19 protection, the opposite is true during wildfires. It's far more critical to ensure that your mask is fitted and leak-free than to avoid touching it.
Avoidance Is the Best Protection
Although masks can help protect us from the harmful pollutants contained within wildfire smoke, there is no better form of protection than avoidance. Of course, we can't always avoid smoke, and when this is the case, a certified mask or respirator is the best choice for protection. However, if it's possible to avoid wildfire smoke altogether, that is the best choice.
By limiting your exposure to dangerous pollutants, you give yourself the best protection. In order to do this, an indoor air purifier can be purchased if needed. If you need to go outside, check the local AQI using your preferred app or website. This will allow you to check local air conditions before venturing out into the potentially contaminated air.
Masks with Replaceable Filters are Best
Masks with replaceable filters are your best choice for wildfire smoke protection. Why? Disposable masks offer excellent protection also, but they have a significant environmental footprint. On the other hand, reusable masks without replaceable filters are bound to have a very short lifespan because the pores in their filters will quickly get blocked in highly concentrated air.
Masks with replaceable filters provide an excellent middle ground. The outer shell of the mask can be washed when needed, and the filters have a more minor environmental impact due to being smaller and (typically) having a longer lifespan than disposable masks. With that being said, it's good to have some disposable masks on hand if you can't use a reusable mask for whatever reason.
How to Correctly Fit a Mask for Wildfires
Silicone seal on the AirPop Light SE.
A correctly fitting mask or respirator is always essential. We would go so far as to say that the fit of a device is as crucial as filtration. For that reason, AirPop spent a long time developing the silicone seal that is now used on our devices. This seal is specifically designed to provide a leak-free fit with minimal adjustments.
While filtration often gets most of the attention - N95, KN95 and KF94 devices all have their filtration capabilities included in the name - filtration is only applicable to a fitted device that has no leaks. As such, it’s essential to put as much emphasis on fit.
When it comes to wildfire smoke and the extreme pollutant concentrations that it brings, fit is more important than ever. Therefore, it’s of the utmost importance that you find and use a mask that provides a secure seal with no leaks. In order to judge whether a mask fits you, there are a few steps that we can take.
First and foremost, fit the mask using earloops or head straps. If the device uses earloops, place these over your ears and adjust the tightness until the mask feels secure but not uncomfortable. If the device uses head straps, place one below your ears (near the top of your neck) and one above your ears.
Once the mask or respirator is in place, start adjusting the metal nosepiece with both hands. You should be able to mould this piece around the bridge of your nose in order to prevent leaks. Typically, most leaks will occur in this location, so the wire must be moulded correctly.
Finally, you can test the fit. To do this, place your hands over the device in a cupping-like fashion. When you inhale, the device should pull in towards your face. When you exhale, the device should expand, but there should be no leaks. Repeat these steps a few times to ensure there are no leaks around the mask (1).
If there are leaks near the top of the mask, try remoulding the wire nosepiece. If there are leaks near the bottom or sides of the mask, try adjusting the headbands or earloops. While these should remove most leaks, there are times when a good seal just isn’t possible. Consider finding a respirator or mask that better fits your face when this is the case.
In the case of AirPop, there is no wire nosepiece included in our masks. We opted to use a silicone seal instead, as this provides a universal fit that is less finicky. By adjusting the earloops, it should be possible to get the silicone seal in a location that offers a good seal while remaining comfortable.
If you cannot achieve a leak-free seal, try moving the filter slightly up or down. Often an ineffective seal is caused due to the silicone being placed too low on the wearer’s nose. Instead, the top of the mask should sit slightly underneath where glasses would sit on your nose.
Finally, as with all masks, make sure to perform a seal check. While the AirPop Original, Active and Active+ are more challenging to perform inhalation-collapse checks on due to the filter being on a different layer, it’s still possible to perform exhalation checks. Both checks can easily be carried out on the Light SE and Pocket masks.
Wildfire smoke is a health concern that we must be cautious of. Especially if you live in a fire-prone location, make sure that you are aware of the dangers of wildfire smoke and the necessary steps to protect yourself. This includes making sure that you have capable respiratory filtration devices on hand.
Smoke is often considered gas, and many people know that standard respirators are ineffective against such particles. However, the most significant danger for most people is not the gaseous particles contained within wildfire smoke but actually the fine and ultrafine dust particles within.
Certified masks and respirators are very capable of filtering these particles - even when they can be as small as 0.1μm. As such, masks effectively protect us from many of the harmful effects of wildfire smoke.
There are many factors to keep in mind when it comes to which device is best suited for wildfire smoke protection. We cover them in more detail in this post. However, on top of the aspects mentioned in that article, there are a few extra points to keep in mind.
If you have decided to skip straight to the conclusion of this article, let us summarise what you should be looking for in a device suited for smoke protection:
- Ensure that the device has an official rating (such as N95, KN95, KF94 or FFP2) or has undergone lab testing by trusted third-party laboratories.
- If possible, look for a mask that has a user-replaceable filter. These devices will allow you to swap out the filter when the mask gets clogged.
- A well-fitting mask is essential. Often, a mask that provides lower theoretical filtration but fits well will offer higher overall protection than a mask with higher filtration performance, but that doesn’t seal correctly.