When Air Turns Toxic: Your Essential Gas Mask Guide

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Choosing a proper gas mask can literally be the difference between life and death. In the event of excessive smoke or chemical exposure, your gas mask can be the only thing standing between you and the horrid side effects of not getting enough oxygen.

Plus, you rarely get the chance to really test a gas mask before you need it.

In this gas mask guide, you will learn everything you need to know about gas masks and the practicality of having one for an emergency.

Gas Mask Guide
Two of Kristin's gas masks with filters next to storage cans
We have experience with multiple types of gas masks

Because this topic is so important, I consulted with several experts. One of the experts was Blake, a member of our team who used gas masks in the military.

While many people assume gas masks are only for protection against chemical gases and crowd-control agents, this isn’t the case. Masks are also important for wildfires and disease events. Even if you aren’t planning on surviving a nuclear explosion, a gas mask is still a great option to add to your prepping arsenal.

After all, as we know from the survival rule of 3, you can only survive three minutes without clean air!


Gas Mask Guide – Simple Tips

A mask is simply a barrier between you and the air around you. There are many types of masks, ranging from surgical masks to full gas masks. The term “gas mask” is a bit misleading, as they don’t just protect against gas. Gas masks are full-face masks that tend to be much more effective than the average surgical mask.

Many people will call gas masks “respirators,” which is exactly what they are. However, the gas mask lingo has stuck around since WWII.

Gas masks can be a key part of prepping gear. They provide protection against riot control agents, biological threats, smoke, and diseases. If there is anything bad in the air, they can protect you from it.

Types of Gas Masks (and Respirators)

There are a few different kinds of gas masks and respirators that you should keep in mind when choosing.

Air-purifying respirators

Most gas masks fall into this category. These respirators use filters within the mask to filter contaminants from the air. They do have some limitations. For instance, you have to have a filter, and this filter can potentially stop working. There are more parts involved than in your average surgical mask, so more things can go wrong.

They also don’t use power to suck in air, so your breathing may be affected. They require around 19.5% oxygen in the air to work. Otherwise, you may suffocate.

Escape respirators are designed to help you escape a dangerous area (like somewhere with a wildfire). Full-face gas masks also fall into this range. All the gas masks in our best gas mask review article fall into this category.

Air-supply respirators

Some respirators don’t filter the outside air. Instead, they provide the air you need. Scuba gear is the most obvious example of this. However, a hazmat suit with an included air source is another option. These are less common and more expensive.

While these work even without sufficient oxygen in the air, they do require a supply of oxygen. Once you run out, they are useless. Exactly how many minutes of air you have varies from system to system.

Types of Filters

For a gas mask to work, you also need a proper filter. I recommend purchasing the most comprehensive filter you can find. Yes, these can be a bit more expensive, but they usually aren’t that much more expensive than a basic filter, and they’ll be far more protective than a simple particle filter.

Two of Kristin's Gas Mask Filters
Know the right type of filter that you need

You never know why you’ll need a gas mask. For instance, you may assume that you only need protection against smoke because you live in a wildfire prone area. However, if you suddenly find yourself in a riot situation, having protection against crowd control gasses is a nice plus.

Modern filters typically follow a universal rating system, which helps you determine what a specific filter is protective against. All NATO filters follow this system, and most modern filters are NATO-compliant.

This system is color-coded, with each color representing a particular substance. Each category will also have a “class” of 1 to 3, representing how effective that mask is against that substance. A 1 is the most protective, while a 3 is the least protective.

The vast majority of masks will have several colors, as most protect against many substances.

Here’s a table of all the gas mask filter ratings:

Color CodeCorresponding LetterContaminates Protected AgainstExample Applications
BrownAXOrganic gases and vapors with a boiling point under 65 CHandling Acetone
BrownAOrganic gases and vapors with a boiling point over 65 CSolvents, paints, and glue
GrayBInorganic gasses and vaporsChlorine, hydrogen sulfide, hydrogen cyanide
YellowESulfur dioxide, hydrogen chlorideCleaning with certain acids
GreenKAmmonia and ammonia derivativesHandling manure
BlackCOCarbon MonixideCarbon Monoxide
RedHgMercuryHandling mercury
BlueNONitrous gassesNitrogen monoxide
OrangeReaktorRadioactive iodineAfter nuclear exlosions
WhitePParticlesBacteria, cutting, drilling, grinding, etc.

There are some other filter standards, though. For instance, NIOSH has filter standards specifically designed for occupational hazards. These filters are more focused on long-term use and substances like dust and pesticides.

CEN is a European regulatory body that also has it’s own standard for filters. Outside of Europe, you rarely see them used, though.

Sometimes, non-NATO filters do offer more targeted protection. However, they’re often harder to find and require a special mask (which may not be as comfortable or practical). In most situations, I recommend using NATO filters simply because they’re compatible with many masks and easy to find.

For more on what CBRN, NBC, and CBA-RCA ratings are, watch the video below.


The Practicality of a Gas Mask

Yes, gas masks can be the only difference between life and death in a serious situation. However, it’s important to realize that gas masks are only a band-aid. They aren’t made for you to live in. Think of them as an escape help. You put your gas mask on and find somewhere with air you can breathe. You don’t hang around.

Kristin showing two gas masks
Gas Masks are essential for evacuations

Many of the complaints involving the practicality of gas masks don’t take this into account. You won’t be able to hang out in a nuclear zone with a gas mask on. However, having one available does keep you safe until you can evacuate to a safe area.

With this in mind, you will need a gas mask for you and everyone in your family. They should be one of your bug out bag essentials and ready to go when the evacuation order comes. Or, if you choose to bug-in (stay home), they can offer some protection in case an air quality emergency occurs.

I recommend keeping as many extra filters as you can, within reason. Two to three per mask is a good medium. Remember, filters do expire, so you’ll need to replace them once a decade or so.

So, What Gas Mask Should You Get?

In most cases, I recommend a full-face gas mask that is compatible with NATO filters. It should fit you well. Beyond that, you should consider the usual factors you keep in mind when buying anything, like durability and value.

It should go without saying but don’t buy cheap, Chinese knock-offs. Purchase from a reputable brand. There are some ways you can test gas masks – somewhat. However, once you open a filter to test it, you can’t reuse it. Therefore, you need to trust that a company’s filters are reliable – not that you just got lucky in testing.

I recommend purchasing a full-spectrum filter. Don’t purchase one to protect you against one thing. You never know when you’ll need a gas mask.

If you have firearms and know how to shoot them, make sure your gas mask is compatible. Many cannot be worn when shouldering a rifle. The visor of the gas mask gets in the way. In a situation when you need a gas mask, tension will likely be high anyway, so now is not the time to sacrifice your ability to protect yourself.

Luckily, they do make gas masks compatible with rifles. Purchase one of these if you have a rifle and feel confident using it.

Blake Shooting a rifle with a Gas Mask on
Blake shooting a rifle with a gas mask

Having a speech diaphragm is also important, but it’s underestimated, in my opinion. Without one, you cannot talk to anyone easily. Don’t purchase one that can be “upgraded” to include a speech diaphragm unless you need that mask for a particular reason.

Whether or not a government or law enforcement agency uses that gas mask can be an important quality indicator. For instance, MIRA safety is currently used by the Czech government.

Consider Fit Above All Else

The fit of the gas mask is important. If the mask doesn’t provide an air-tight seal, it won’t keep contaminated air from seeping into the gas mask. The filter won’t work as intended. This applies to all respirators.

Generally speaking, a tight-fitting gas mask is the best option for most adults. Some people worry about not being able to breathe through a mask. However, this isn’t a problem for anyone with normal lung function.

Blake wearing a gas mask, showing the fit from the back
The fit of the gas mask is important

Children need a hood. Gas masks simply are not made of their faces (and getting your child to wear one and leave it alone would be a task in itself). When purchasing a hood, be sure to consider fit, as well. Mira Safety has a few good options for children.

Ensuring a Proper Fit (And Gas Mask Testing)

For your gas mask to work, it has to fit. Luckily, checking that your gas mask fits well is very easy. First, you need to put it on correctly:

  1. Loosen the straps and move them to the side. Otherwise, they can get in your way.
  2. Put your chin into the chin portion of the gas mask first. Then, roll it up slowly from the chin up. Your nose should go in the nose section. If something seems “off,” take the mask off and try again.
  3. Hold the gas mask in place with one hand and tighten the straps. Blake recommends starting with the straps on the side of the head and then doing the ones on the top.

Once the mask is on your face, block the filter with your hand and inhale deeply. The mask should suction to your face and tighten. If it does, you have a seal (and the gas mask likely works). Congrats!

If you don’t have a seal, try again. Sometimes, you can hear where the air is seeping through when you do the pressure test. A quality gas mask will seal. If it doesn’t, it won’t work.

If you have a large beard, that can get in the way of a proper seal. So consider this in an emergency.

What About Military Surplus?

Many individuals online will recommend military surplus gas masks. However, I don’t recommend these for a few reasons. These gas masks are widely available but typically only sold on marketplaces like eBay. You cannot guarantee the truthfulness of any sellers on these platforms.

Most only sell gas masks for collecting purposes. Therefore, they don’t test to see if the gas mask still works and often don’t expect anyone to use their masks.

Furthermore, most surplus gas masks are expired. That’s why they’re thrown into the “surplus” pile. You cannot trust an expired gas mask.

Even if the gas mask isn’t expired, it’s very likely at least a few years old, shortening how long you can store it. Surplus masks often aren’t much cheaper than other options, so there is little reason to sacrifice years of use.

Gas Mask Maintenance and Storage Tips

After you’ve selected a gas mask, you need to store and maintain that mask properly. No one wants to ruin a several hundred-dollar mask by storing it incorrectly. Sunlight is surprisingly rough on rubber!

Kristin showing how to store a gas mask
Ammo cans are a great way to store a gas mask

Every time you wear your gas mask, be sure to wipe it down well with a damp cloth. Of course, this isn’t going to happen in an emergency situation. However, if you’re just practicing with your mask, be sure to clean it properly. Pay extra attention to the facepiece. Sweat can degrade the rubber over time, leading to gas mask failure.

Different materials can require different cleaning and storage techniques:

  • Silicone: Clean with mild soap and water. Don’t use abrasive cleaners. These masks can become brittle if exposed to heat for too long, eliminating their ability to seal.
  • Rubber: The most popular gas mask material. Avoid harsh chemicals and solvents when cleaning. Heat also damages these masks, making them warp and crack.
  • Thermoplastic elastomers: Use a mild soap and water only. While these are somewhat more heat resistant, high temperatures can make them softer.

Don’t wash the filters! Their effectiveness hinges on the activated carbon inside. You should replace them according to the manufacturer’s instructions or after they’re used. You cannot wash a filter to make it “reusable.”

Store the mask somewhere cool and dry away from direct sunlight. Leaving the gas mask in the car may seem like a great idea. However, the extreme cold and extreme heat of your car can make the mask degrade faster.

Seal everything in a plastic bag or airtight container. You want to protect it from dust, dirt, and insects. These can destroy a mask before its original expiration date.

Even with proper storage, masks can degrade faster or be involved in accidents. It’s important to check your mask regularly for signs of wear, cracks, or damaged rubber. You’ll need to replace your mask in these situations, and it’s much better to find out it’s broken before an emergency – not during one.

Avoid modifying the mask or trying to use replacement parts from anyone but the manufacturer. It’s just too risky.

Filters also have a finite life. Watch the video below for a great explanation of how long filters will last.


What Next?

Next, read our best gas mask review. We review the best ones available plus the best filters for them.

After you’ve purchased a quality gas mask, you need to train with it. You should practice putting it on and taking it off at least a few times (and have everyone else in your family practice, too). In an emergency, you’ll be stressed and revert back to your lowest level of training. Ensure putting a gas mask on is in that category.

Next, wear a gas mask around your home. Breathing in a gas mask can be a bit weird, and your field of view may be affected. Just performing normal tasks, like cooking dinner, can help you get used to it.

Practice shooting in a gas mask too. I recommend going through some of the drills in our best concealed carry training guide while wearing the mask.

If you have not already, be sure to follow our How to Start Prepping guide. It has everything you need to know to be prepared for an emergency.

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Kristin is a fulltime writer with an obsession for being prepared. She spends much of her time working towards making her family self-sufficient, including homeschooling her children. When she isn’t writing, she’s shooting with her husband or homesteading.