Disclaimer: The content provided in this blog is for informational purposes only and should not be considered professional advice. For your specific respiratory protection needs or concerns, you should seek guidance from a health and safety expert. Always follow local regulations and safety standards for your workplace and jurisdiction.
If you're wearing a respirator with the wrong type of filters for your airborne hazard, then you might as well be wearing nothing at all.
All too often, we come across people wearing only particulate filters when their hazard is chemicals/gases/vapours. Or we see folks using only gas/vapour filters when the contaminant is harmful particulates, such as respirable crystalline silica.
With so many filters available, understanding which ones suit your environment can be confusing.
In this article, we'll dive into the differences between the two main types of filters - particulate and gas/vapour. We'll review when to use them and how to choose the right one for your specific needs.
Please note: The information in this post pertains to reusable half-face and full-face respirators where filters can be interchanged. Filtering facepiece particulate respirators - such as N95 and P2 disposable masks - will not be discussed.
Understanding Particulate vs. Gas/Vapour Filters vs Combination Filters
In many industries, workers are exposed to airborne hazards that can seriously affect their health. Whether it’s fine dust from construction work, harmful vapours in chemical processing, or smoke particles in firefighting, it’s critical to have the right respiratory protection to protect you from these contaminants.
Particulate Filters
Particulate filters protect against solid particles, like dust, mists, and smoke. These are the filters you would use when dealing with hazards such as asbestos, silica, coal dust, and wildfire smoke to name a few. These are substances that, when inhaled, can lead to severe lung diseases like silicosis, asbestosis, mesothelioma, chronic obstructive pulmonary disease (COPD), and lung cancer.
Other body systems can also be affected by toxic respirable particles causing widespread damage. For example, silica dust not only causes silicosis, it can lead to other serious ailments such as autoimmune diseases and kidney failure.
Particulate filters come in several efficiencies. Different countries have different nomenclatures for their filters. In Australia, the most commonly used designations are P1, P2, and P3.
P1 Filters: Filter ~80% of mechanically generated particles
P2 Filters: Filter ~ 94% of mechanically and thermally generated particles
P3 Filters: Filter ~ 99.95% of mechanically and thermally generated particles.
Particulate filters do NOT protect you against chemicals, gases and vapours.
Gas/Vapour Filters
Gas and vapour filters (usually called cartridges) are designed to protect against harmful, airborne chemicals, gases and vapours.
These filters are critical in environments where chemicals are used or processed, such as in painting, cleaning with solvents, or working with hazardous gases like ammonia or chlorine just to name a few.
Gas and vapour filters contain activated charcoal, which works through a process called adsorption. As air passes through the filter, the gas or vapour molecules are trapped on the surface of the charcoal, preventing them from being inhaled.
Gas and vapour filters are categorized based on the type of chemicals they are designed to filter. They are colour-coded and the colours are the same across all brands. Gas and vapour cartridges also come in various absorption capacity levels. The higher the number, the more contaminate the cartridge can absorb.
The most common filter classes include:
It’s critical to match the gas or vapour filter to the specific chemicals in your workplace. Using the wrong filter may provide little to no protection, leaving workers vulnerable to harmful exposures.
Gas and vapour cartridges do NOT protect you against particulates like dust and smoke.
Combination Filters
In many cases, workers are exposed to both particulate and gas/vapour hazards. For example, spray painting produces fine mist particles and harmful organic vapours. In these situations, a combination filter will protect against both types of hazards.
Combination filters are essentially two filters in one: a particulate filter and a gas/vapour filter. The photo above is an example of an ABEK gas/vapour cartridge with a P3 particulate filter housed in the front.
When selecting a combination filter, make sure that it meets the required protection levels for both the particulate and the gas/vapour hazard.
Selecting the Right Filter
When choosing between particulate and gas/vapour filters, it’s essential to conduct a risk assessment of your work environment. Determine whether your primary hazard is particles, gases/vapours, or a combination of both.
When choosing the particulate component of the filters, you need to know if you require P1, P2 or P3 efficiency.
If your hazard is gas/vapours, then you must know what type of gases and vapours you're dealing with. Organic? Inorganic? Acid gases? Amonia? Mercury?
When it comes to gas/vapour filters, we've noticed that many people go full throttle and get the ABEK because they're unsure of what category the hazard falls under. We advise against this for a couple of reasons:
The more layers of protection, the higher the cost of the cartridge.
Cartridges with multiple layers are heavier and increase breathing resistance.
Of course, some environments do require multiple levels of coverage. But, for example, if your only hazard is an organic gas (A, Brown), then there's no need to get an ABEK cartridge.
And one more thing to note about gas/vapour cartridges. It's common to use these along with particulate filters even if toxic particulates are not identified in your environment. The particulate filter can protect the life and longevity of the gas/vapour cartridge.
Seek Professional Advice
It's really important to get the selection of your respirators and filters right. Especially if your environment contains multiple hazards.
You may need to undertake air monitoring to determine if exposure levels are being exceeded and if RPE is even required. And if RPE is required, what assigned protection level do you require and what type of filters will be adequate?
It can get complicated.
If you're not 100% sure you're choosing the right RPE, consult with a certified occupational hygienist or health and safety expert who is well-versed in the selection and use of respiratory protective equipment.
Wrapping Up
Understanding the differences between particulate filters and gas/vapor filters is critical for selecting the appropriate respiratory protection in hazardous environments.
Using the wrong filter can leave workers exposed to dangerous contaminants, leading to serious health consequences. Always ensure that the filter you choose is appropriate for the hazards in your workplace. And remember that combination filters are available for environments where both particulate and gas/vapour contaminants are present.
If you're not entirely sure that you're choosing the right RPE, always engage with a health and safety professional, such as an occupational hygienist, who understands how to select and use respirators.
For more information on filters, check out this article: https://www.fittestvic.com.au/post/quick-guide-respirator-filters-and-cartridges
And if you're looking for mask fit testing, respiratory protective equipment courses or help implementing a respiratory protection program, get in touch with us.
0488 688 454
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