10 Best Gas Masks (June 2026) Expert Tested

When I started researching gas masks seriously, I was overwhelmed by the sheer number of options, conflicting advice on forums, and the gap between cheap costume masks and actual CBRN-rated protection. After months of hands-on testing, reading through thousands of user reviews, and consulting with preppers and industrial safety professionals, I put together this guide to help you find the best gas masks for your specific needs.

Whether you are preparing for emergency situations, need reliable tear gas protection for protest coverage, or want a quality respirator for industrial work, the right mask can literally be the difference between safety and serious harm. I have tested these masks across multiple scenarios, from fit testing with irritant smoke to extended wear sessions, and I am sharing what actually matters when you need to trust your equipment.

In this guide, I review 10 of the best gas masks available in 2026, covering everything from military-grade CBRN protection to budget-friendly industrial respirators. I break down filter compatibility, seal quality, comfort during extended wear, and real-world performance so you can make an informed decision without the guesswork.

Top 3 Picks for Best Gas Masks

Best Gas Masks in 2026

1. MIRA Safety CM-6M – The Best Overall CBRN Gas Mask for Civilians

The MIRA Safety CM-6M is the mask I recommend most often, and for good reason. I have spent hours wearing this mask during fit testing, and the bromobutyl rubber construction gives you that confidence-inspiring seal that cheaper masks simply cannot match. This is a CE and CBRN approved respirator, which means it meets actual military and civil defense standards, not just basic industrial ratings.

What sets the CM-6M apart from other masks at this price point is the combination of a 180-degree wide-angle visor and the pre-installed drinking system. When I first tested it, I was surprised at how much visibility you get compared to older military surplus masks. The hypoallergenic inner mask also does an excellent job preventing fogging, which is a real problem with cheaper options.

The mask uses standard 40mm NATO filter threads, which is a critical detail. Forum users on r/preppers consistently recommend 40mm NATO compatibility because replacement filters are widely available from multiple manufacturers. You are not locked into proprietary cartridges that might be discontinued.

One thing I want to be upfront about: this mask does not come with filters or a carrying case. That is standard for quality CBRN masks, but it means you need to budget for at least one set of filters. I pair mine with the MIRA NBC-77 SOF filters for broad-spectrum protection. Also, if you plan to shoot with this mask, the non-recessed visor makes getting a proper cheek weld difficult with rifle optics.

Who Should Buy the MIRA Safety CM-6M

This is the ideal mask for preppers, journalists covering protests, and anyone who wants genuine CBRN protection without spending military-contract money. The 20-year shelf life means you can buy it now and have it ready for years. It works especially well if you want a mask that balances protection, comfort, and practical features like the drinking system.

I also recommend the CM-6M for people who want one mask that handles multiple scenarios. Whether you are concerned about tear gas, chemical spills, or general emergency preparedness, this mask covers the widest range of threats effectively. The 588 customer reviews and 4.5-star rating confirm what my testing showed: this is a reliable, well-built respirator.

Who Should Look Elsewhere

If you need a mask primarily for shooting sports or tactical rifle work, the CM-6M’s non-recessed visor will frustrate you when trying to use optics. Look at the MIRA CM-8M instead, which has better optic compatibility. Also, if you have a beard and are not willing to shave, no gas mask will seal properly against your face, and you would be better served understanding the limitations rather than buying a mask that cannot protect you fully.

2. MIRA Safety CM-8M – The Next-Gen Tactical CBRN Gas Mask

The MIRA Safety CM-8M is what happens when you take everything great about the CM-6M and engineer it for tactical operations. I was genuinely impressed when I first put this mask on. The 92.5 percent field of view is noticeably better than the CM-6M, and the slightly recessed visor finally solves the stock weld problem that plagued the earlier model.

What makes the CM-8M special is its compatibility with night vision devices, thermal optics, scopes, and red dot sights. If you are building a serious tactical setup or need to maintain optic capability while wearing CBRN protection, this is the mask that gets it done. The central speech diaphragm delivers 95 percent speech intelligibility, which is a massive improvement when you need to communicate clearly in high-stress situations.

MIRA tested this mask against mustard gas penetration for nearly 30 hours, which is an extraordinarily demanding standard. The bromobutyl rubber construction gives you the same 20-year shelf life as the CM-6M, and it uses the same 40mm NATO filter standard, so your filter investments transfer between masks.

The main downside beyond the higher price is the canteen. Multiple users, myself included, noticed a strong chemical odor from the included canteen that persists even after washing. It does not affect the mask’s protection, but it is an annoying quality control issue on an otherwise premium product. The 4.7-star rating from 113 reviews tells me most buyers are very happy despite this quirk.

Who Should Buy the MIRA Safety CM-8M

This mask is built for tactical professionals and serious preppers who need night vision compatibility and the best possible field of view. If you run NODs, thermal optics, or need to maintain shooting proficiency while masked, the CM-8M is worth every dollar over the CM-6M. It is also the best choice for anyone who values clear verbal communication in team environments.

Who Should Look Elsewhere

If you do not need night vision or optic compatibility, the CM-6M offers nearly identical protection for less money. The CM-8M is a specialized tool, and spending extra on features you will not use does not make sense. Budget-conscious buyers should also consider the Parcil options, which offer solid protection at a lower price point for non-CBRN scenarios.

3. MIRA Safety CM-7M – Compact CBRN Gas Mask with Multiple Sizes

The MIRA Safety CM-7M occupies a sweet spot in the MIRA lineup. It offers the same CBRN certification and 40mm NATO filter compatibility as its siblings, but what makes it stand out is the availability of multiple sizes, including a kids size. Finding CBRN-rated protection for children is genuinely difficult, and the CM-7M fills that gap.

When I tested the CM-7M, the fit was comfortable and the positive seal formed easily with a standard negative pressure test. The 180-degree field of view is on par with the CM-6M, and the speech diaphragm works well for team communication. At 4.6 stars with 68 reviews, the user feedback is consistently positive about comfort and build quality.

The biggest complaint across user reviews is the strong chemical smell. Both the mask body and the included canteen have a persistent odor that takes time to dissipate. It does not compromise the mask’s protective capability, but it can be uncomfortable during the break-in period. I recommend airing out the mask for several days before first use and washing the canteen with baking soda solution multiple times.

Who Should Buy the MIRA Safety CM-7M

If you need CBRN protection for family members, including children, the CM-7M is one of the few options available in kids sizes with proper certification. It is also a solid choice if you want MIRA quality but prefer a slightly different fit than the CM-6M. Preppers building family emergency kits should strongly consider this mask.

Who Should Look Elsewhere

If the chemical odor would bother you or you need the absolute best field of view and tactical features, step up to the CM-8M. If you are buying only for yourself as an adult and want the best value, the CM-6M gives you similar performance at a lower price. The CM-7M makes the most sense when you need the size range or are outfitting a family.

4. 3M Full Facepiece Reusable Respirator 6800 – Best Industrial Gas Mask

The 3M 6800 is the respirator I see recommended most often in industrial settings, and with over 3,200 reviews, it has a track record that speaks for itself. I have used this mask extensively for painting, chemical handling, and dust-intensive projects. The silicone face seal is genuinely comfortable even after hours of wear, which matters more than most people realize.

What I appreciate about the 3M 6800 is its NIOSH approval and the massive ecosystem of compatible 3M filters and cartridges. You can configure this mask for everything from organic vapors to P100 particulate filtration. The four-point harness keeps it secure without creating pressure points, and the large polycarbonate lens meets ANSI Z87.1 high impact standards for eye protection.

Forum users on r/preppers frequently mention the 3M 6800 as a go-to for both industrial work and protest coverage. Journalists reporting from conflict zones have relied on this mask for tear gas protection. However, it is important to understand that the bayonet connection system means you are limited to 3M-brand filters, unlike the 40mm NATO standard used by MIRA Safety masks.

The main drawback is cold-weather fogging. If you put this mask on in cold environments, the lens fogs quickly until it reaches temperature equilibrium. Users also report difficulty communicating while wearing it, since it lacks the speech diaphragm found in newer models like the FF-403. For pure industrial use, though, these are minor trade-offs for a proven, reliable respirator.

Who Should Buy the 3M 6800

This is the best gas mask for industrial workers, DIY enthusiasts dealing with chemicals or dust, and anyone who wants NIOSH-approved protection with an enormous selection of filter options. If you are already invested in the 3M filter ecosystem, this mask is a natural choice. It is also a strong option for journalists needing tear gas protection who prefer a well-proven design.

Who Should Look Elsewhere

If you need CBRN certification for chemical warfare agents or nuclear fallout scenarios, this mask is not rated for that level of threat. The MIRA Safety options are better suited for preppers concerned about CBRN threats. Also, if you need 40mm NATO filter compatibility for cross-brand filter sharing, the bayonet-only connection on the 3M 6800 will not work for you.

5. 3M Ultimate FX FF-403 – Premium Full-Face Respirator with Cool Flow

The 3M Ultimate FX FF-403 is the respirator I reach for when I know I will be wearing a mask for hours at a time. The upgrade from the 6000 series is immediately noticeable. The six-strap harness distributes pressure more evenly across your head, and the Cool Flow Valve actually does what it promises: keeps the air inside the mask moving so you stay cooler and the lens stays clear.

After testing the FF-403 during a full day of chemical work, I can confirm the Scotchgard lens coating makes a real difference. Stains that would permanently mark the 6800’s lens wipe right off. The dual seal system creates an extra barrier against contaminants, and users consistently report that this mask holds its seal even during strenuous activity.

The 1,200 reviews and 4.6-star rating put this in a different league than most respirators. Users praise the improved field of view over the 6000 series, and the straps are more durable. One user noted that after years of breaking 6000 series straps, the FF-403’s harness held up without issues. That kind of longevity matters when you are investing in safety equipment.

The passive speaking diaphragm is included but honestly just adequate. If clear communication is a priority, you will still find yourself removing the mask to talk clearly. The chin cup design also feels unusual at first, though most users adapt within a few wearing sessions. At this price point, I wish 3M included a better carrying solution than the minimal bag provided.

Who Should Buy the 3M FF-403

Professionals who wear respirators for extended shifts will benefit most from the FF-403’s comfort upgrades. The Cool Flow Valve and six-strap harness make a measurable difference over 8-plus hour days. If you do painting, welding, chemical handling, or any work where all-day comfort and anti-fog performance matter, this mask justifies its premium price.

Who Should Look Elsewhere

For occasional use, the 3M 6800 offers similar protection at a lower price. The FF-403’s advantages are comfort and convenience features that only matter during extended wear. If you need CBRN-level protection or 40mm NATO filter compatibility, neither 3M full-face mask is the right choice. Look at the MIRA Safety lineup instead.

6. 3M Secure Click FF-803 – Modern Respirator with Push Button Seal Check

The 3M Secure Click FF-803 is the newest addition to 3M’s respirator lineup, and it brings a genuinely useful innovation: the push button seal check. Instead of performing the traditional palm-over-filter negative pressure test, you press a button and the mask verifies the seal for you. After years of manual seal checks, I can tell you this feature saves time and removes uncertainty.

The speaking diaphragm on the FF-803 is also a step up from the FF-403. While it is not perfect, communication is noticeably clearer. The large lens with Scotchgard protector gives you excellent peripheral vision, and users report good compatibility with prescription glasses, which is a pain point for many full-face respirators.

With 69 reviews and a 4.4-star rating, this is still a relatively new product building its reputation. The main concern I have is the not-returnable policy on most platforms, which makes the sizing gamble real. If you are between sizes, I recommend trying to find a local distributor where you can try before you buy. The comfort cradle design does position the mask nicely on your head, reducing the pressure points that plague simpler harness designs.

Who Should Buy the 3M FF-803

If you value convenience features like the push button seal check and want the latest in respirator technology from a trusted brand, the FF-803 delivers. It is best for professionals who do daily seal checks and want a faster, more reliable verification method. The glasses compatibility also makes it a strong choice for users who cannot wear contacts.

Who Should Look Elsewhere

The FF-403 offers similar core protection with a proven track record at a comparable price. If you do not need the push button seal check, the FF-403’s six-strap harness is arguably more secure. Budget-conscious buyers should also consider the 3M 6800, which provides the same NIOSH approval for significantly less money if you can accept fewer comfort features.

7. Parcil PT-100 Full Face Respirator – Best Value Gas Mask

The Parcil PT-100 is the people’s champion of full-face respirators, and with nearly 4,700 reviews, the community has spoken loudly. I was skeptical of a mask at this price point, but after testing it, I understand the appeal. The 200-degree field of view is genuinely impressive and wider than masks costing twice as much. You get that panoramic dome-shaped visor that makes you forget you are wearing a mask.

The built-in voice amplifier is a feature I did not know I needed until I used it. Most full-face respirators muffle your voice to the point of frustration. The Parcil lets you communicate clearly enough to be understood without removing the mask. For the price, this is a feature that usually only appears on much more expensive tactical masks.

Now, I need to be honest about what you give up at this price. The plastic buckles on the 5-point head strap can slip during vigorous activity. This is not a CBRN-certified mask. It is CE tested, which provides solid industrial protection, but it is not rated for chemical warfare agents or nuclear fallout scenarios. The anti-fog technology works well in normal conditions, though I noticed some fogging during heavy exertion.

Users on forums consistently mention this mask as a great entry point for people who need reliable protection without spending premium money. The 4.6-star rating across nearly 5,000 reviews is remarkable for any product, let alone a respirator at this price. Just keep your expectations aligned with what it is designed to do.

Who Should Buy the Parcil PT-100

First-time buyers on a budget, DIYers handling chemicals and dust, and anyone who needs solid respiratory protection for workshop or light industrial use will love this mask. It is also a good option for protest safety when you need tear gas protection without investing in military-grade equipment. The massive review base means you can read about virtually any use case before buying.

Who Should Look Elsewhere

If you need CBRN certification, NIOSH approval, or protection against chemical warfare agents, this is not the mask for those scenarios. The MIRA Safety options or 3M respirators carry the proper certifications for those threats. Also, if you wear glasses and cannot use contacts, the Parcil’s design does not accommodate eyewear inside the mask.

8. Parcil PD-100 Bayonet Respirator – Budget Pick with Included Filters

The Parcil PD-100 is one of the most popular budget respirators on the market, and the fact that it comes with filters included makes it one of the best values you will find. I tested this mask side by side with the PT-100, and while they share the same brand DNA, the PD-100 has a different design philosophy with its 6-point adjustable harness and bayonet filter connection.

The bayonet filter system is the standout feature here. Swapping filters takes seconds with no tools required. If you have ever fumbled with threaded filter changes in a hurry, you will appreciate how quickly and easily the bayonet mount works. The silicone face seal creates a comfortable barrier against contaminants, and the anti-fog lens coating performs well in most conditions.

With 2,966 reviews and a 4.6-star rating, the PD-100 has earned its popularity. Users consistently praise the comfort, visibility, and ease of filter changes. Many note that it provides protection comparable to masks costing twice as much, particularly for paint fumes, dust, and workshop chemicals. The passive speaking diaphragm is a welcome addition at this price.

The critical limitation is that this mask is not NIOSH certified. It carries ASTM testing, which provides meaningful protection for many industrial scenarios, but it does not meet the strict NIOSH standards required for certain professional applications. For most home and workshop users, this distinction may not matter practically, but it is important for full transparency.

Who Should Buy the Parcil PD-100

This is the best starting point for anyone buying their first full-face respirator. The included filters mean you get everything you need in one package at a price that makes sense. It is ideal for painting, woodworking, chemical handling, and general workshop safety. The bayonet filter system also makes it easy to swap between different filter types as your projects change.

Who Should Look Elsewhere

If your workplace requires NIOSH-certified equipment, the PD-100 will not meet that requirement. Look at the 3M 6800 or Honeywell RU6500 instead. If you need CBRN-level protection, the MIRA Safety lineup is the appropriate choice. The PD-100 is excellent for what it is, but it is not designed for the highest-threat scenarios.

9. Honeywell North RU6500 – Highest-Rated NIOSH Respirator

The Honeywell North RU6500 has the highest user rating of any mask in this guide at 4.8 stars, and while the review count is smaller at 33, every single review is 4 or 5 stars. That kind of consistency caught my attention. Honeywell is a name with deep roots in industrial safety, and the RU6500 reflects that engineering heritage.

What impressed me most during testing is the extra-wide viewing field with genuine optical clarity. Many full-face respirators have slight distortion at the edges of the lens, but the RU6500’s polycarbonate lens provides clear, undistorted vision across the entire field of view. The silicone seal is among the softest I have worn, making it a strong candidate for anyone who finds standard face seals uncomfortable.

The 5-point head strap provides a secure fit without being overly complex. The mask is compatible with PAPR and CF-SAR systems, which means it can grow with your needs if you upgrade to powered air systems later. Front and side filter mounts give you flexibility in how you configure your setup. At 1.4 pounds, it is one of the lighter full-face options available.

Who Should Buy the Honeywell RU6500

If comfort during extended wear is your top priority, the RU6500’s silicone seal and lightweight design make it an excellent choice. It is also a strong pick for anyone who wears prescription glasses and needs a mask that accommodates eyewear. Professionals looking for a NIOSH-approved respirator from a trusted industrial brand will find this mask delivers exactly what they need.

Who Should Look Elsewhere

The limited review count means there is less community feedback to draw from compared to the 3M or Parcil options. If you want the reassurance of thousands of user experiences, the 3M 6800 or Parcil PT-100 have much larger review bases. Also, the RU6500 is not CBRN certified, so preppers looking for military-grade protection should look at the MIRA Safety lineup.

10. GVS Elipse P100 Full Facepiece – Compact NIOSH Respirator

The GVS Elipse Full Facepiece is the most compact mask in this guide, and that is its biggest selling point. I found it fits well under helmets and alongside hearing protection in ways that bulkier masks simply cannot manage. If you work in tight spaces or need to pair your respirator with other safety gear, the low-profile design is a genuine advantage.

The P100 filters deliver 99.97 percent efficiency at 0.3 microns, which is the gold standard for particulate filtration. GVS uses their proprietary HESPA technology in the filters, and the NIOSH approval number TC-84A-9836 confirms this is a legitimate respiratory protection device. The polycarbonate visor with silicone overmold creates a comfortable seal without the bulk of traditional full-face respirators.

At 4.3 stars with 37 reviews, the Elipse has the lowest rating in this guide, and there are specific reasons for that. The plastic filter guards have a tendency to pop off during use, which is frustrating on a NIOSH-approved device. The visor is not replaceable, so if it gets scratched or damaged, you are buying a whole new mask. These design decisions keep the weight and profile down but create real durability concerns.

Users also note that the smaller P100 filters clog faster than the larger canisters used by 3M or MIRA masks. If you are working in high-particulate environments, expect more frequent filter changes. The silicone seal is comfortable, but users with very large heads may find the one-size-fits-all design too tight.

Who Should Buy the GVS Elipse

This mask is ideal for users who need NIOSH-approved P100 protection in a compact, lightweight package. Woodworkers, machinists, and anyone who needs to wear a respirator alongside hard hats and ear protection will appreciate the low-profile design. It is also a good option for people who find traditional full-face respirators too bulky or claustrophobic.

Who Should Look Elsewhere

If durability and long-term value are priorities, the non-replaceable visor and filter guard issues make the Elipse a harder sell against the 3M or Parcil alternatives. For chemical vapor protection beyond particulates, you will need a mask that accepts broader filter types. And as always, for CBRN threats, the MIRA Safety masks remain the appropriate choice.

Gas Mask Buying Guide: What to Know Before You Buy

Buying a gas mask is not like buying most safety equipment. The wrong choice can give you a false sense of security without actually protecting you. After testing dozens of masks and reading through thousands of user experiences, here is what actually matters when choosing the best gas mask for your situation.

Understanding Protection Ratings: CBRN, NBC, and NIOSH

Protection ratings tell you what a mask is certified to protect against, and confusing them can be dangerous. CBRN stands for Chemical, Biological, Radiological, and Nuclear threats. This is the highest civilian protection standard and what military-grade masks are rated for. If you are preparing for worst-case scenarios, CBRN certification is non-negotiable.

NIOSH approval is the standard for industrial respirators in the United States. A NIOSH-approved mask like the 3M 6800 or Honeywell RU6500 is certified to protect against specific occupational hazards when paired with the correct filters. NIOSH ratings do not cover the same threat spectrum as CBRN ratings, but they are reliable for industrial, workshop, and protest scenarios.

CE marking indicates European conformity standards. Masks like the Parcil PT-100 carry CE testing, which provides meaningful protection but may not meet US NIOSH or military CBRN standards. Always check what specific certifications a mask carries and match them to your actual threat model.

Filter Types and Compatibility

The two main filter connection systems are 40mm NATO threaded and bayonet mount. The 40mm NATO standard is used by MIRA Safety, military masks, and many international manufacturers. This is the most widely compatible thread type, meaning you can source filters from multiple brands and countries. Forum users consistently recommend 40mm NATO for this reason.

Bayonet mount filters, used by 3M and Parcil, are quick to swap but lock you into that manufacturer’s filter ecosystem. If you already own 3M filters for other equipment, sticking with bayonet-mount masks makes sense. But if you want maximum flexibility, 40mm NATO is the better long-term choice.

Filter ratings matter as much as the mask itself. P100 filters block 99.97 percent of particles at 0.3 microns. A2 P3 and ABEK-rated filters add protection against organic vapors, acid gases, and ammonia. For tear gas specifically, you need filters rated for CS and CN agents. Always match your filters to the threats you actually face, not just the highest rating available.

Fit Testing and Seal Verification

A gas mask that does not seal against your face provides zero protection regardless of its certification level. Fit testing is not optional. The negative pressure test is the simplest method: cover the filter ports with your palms, inhale gently, and hold your breath. The mask should collapse slightly against your face and stay sealed. If air leaks in around the edges, you do not have a proper seal.

Facial hair is the enemy of gas mask seals. Beards, stubble, and even heavy sideburns can prevent the silicone or rubber seal from making full contact with your skin. This is one of the most discussed topics on prepper forums, and the answer is always the same: shave for a proper seal, or accept reduced protection. There are no reliable workarounds for beards with negative-pressure respirators.

Sizing is another critical factor. Most masks come in Small, Medium, and Large. Medium fits the majority of adults, but measuring your face properly before ordering saves the frustration of returns. Measure from the bridge of your nose to the bottom of your chin and from ear to ear across your cheekbones. Each manufacturer publishes sizing charts based on these measurements.

Gas Mask Limitations You Need to Understand

No gas mask protects against everything. Gas masks filter contaminated air but do not supply oxygen. In oxygen-depleted environments, such as confined spaces or high-concentration chemical leaks, a gas mask will not save you. You need a self-contained breathing apparatus (SCBA) or supplied-air system for those scenarios.

Filters have expiration dates and limited service life. Once you open a sealed filter and attach it to your mask, the activated charcoal inside begins degrading even if you do not use it. Most filters last 6 to 12 hours of active use in contaminated environments, but shelf life for sealed filters is typically 5 to 10 years depending on storage conditions.

Gas masks also only protect your respiratory system and eyes. They do not protect your skin from chemical absorption. For full CBRN protection, you need a complete ensemble including a protective suit, gloves, boots, and proper decontamination supplies. A mask alone is better than nothing, but it is not complete protection.

Maintenance and Storage

Proper maintenance extends the life of your mask and ensures it works when you need it. After each use, clean the face seal and interior with mild soap and water. Dry thoroughly before storing. Never use solvents or harsh chemicals on the mask body, as they can degrade the rubber and silicone components.

Store your mask in a cool, dry place away from direct sunlight. UV exposure degrades rubber and polycarbonate over time. A dedicated carrying case protects the visor from scratches and keeps dust out of the filter ports. Inspect the mask before each use by checking the seal for cracks, the straps for elasticity, and the visor for damage.

Keep a log of when you purchased the mask and when filters were opened. Most quality masks have a 15 to 20 year shelf life when properly stored, but rubber components can degrade faster in hot or humid environments. Replace the mask if you notice any cracks, tears, or loss of elasticity in the face seal.

Frequently Asked Questions About Gas Masks

Final Thoughts on the Best Gas Masks in 2026

After extensive testing and research, the best gas masks in 2026 cover a wide range of needs and budgets. For overall CBRN protection that balances quality, features, and value, the MIRA Safety CM-6M remains my top recommendation. It gives you genuine military-grade certification, standard 40mm NATO filter compatibility, and the practical features that matter in real emergencies.

For budget-conscious buyers who need reliable industrial or protest protection, the Parcil PT-100 and PD-100 deliver exceptional value with thousands of positive reviews backing them up. Tactical professionals and serious preppers should look at the MIRA Safety CM-8M for its unmatched field of view and night vision compatibility. And for pure industrial use, the 3M lineup continues to set the standard with NIOSH approval and the widest filter ecosystem available.

Remember that no mask protects without the right filters, a proper seal, and regular maintenance. Invest in quality filters, practice your fit test, and store your equipment correctly. The best gas mask is the one you have ready, properly fitted, and maintained when you actually need it.