Important note before you start reading: The information provided in this article is not intended as specific advice or guidance for your workplace, as every situation is unique. It is essential to consult with a certified occupational hygienist or a qualified health and safety professional for the appropriate selection and use of respiratory protective equipment (RPE), especially in environments with complex and various airborne contaminants.
Respiratory protective equipment (RPE) constitutes a crucial line of defense against hazardous airborne contaminants in various industrial and occupational settings.
Designed to safeguard the respiratory system, RPE encompasses a diverse range of devices, each tailored to specific needs and exposure scenarios. From reusable half-face and full-face respirators that rely on negative pressure to filter out contaminants, to powered air-purifying respirators (PAPRs) delivering purified air through motorized systems, and air-supplied respirators ensuring an uninterrupted supply of clean air, the spectrum of RPE options is extensive.
The selection of the appropriate RPE is guided by standards such as AS/NZS 1715:2009, which outlines performance criteria, fit testing, and maintenance protocols.
It's important to note that RPE is just one measure to keep workers safe from harmful airborne hazards.
This article is a bit longer than our typical blog posts. Feel free to digest it from start to finish or you can jump straight to any of these topics:
AS/NZS 1715:2009
AS/NZS 1715:2009 is the Australian/New Zealand Standard that provides guidance on the selection, use, and maintenance of respiratory protective devices. The standard outlines the performance and testing requirements for various types of respirators, ensuring that they effectively protect against the inhalation of hazardous airborne contaminants. It also covers proper training, fitting, and maintenance procedures to ensure the ongoing effectiveness of these devices.
Under this Standard, all employers that require workers to wear RPE should have a comprehensive respiratory protection program in place.
A proper respiratory protection program includes many components such as appointing an administrator, risk assessment, respiratory selection process, fit testing, training, record keeping, and program evaluation.
Be sure to purchase a copy of this Standard and familiarise yourself with the requirements.
What is a Respirator and How Do They Work?
Respirators vs Masks - They are not the same!
First, let's talk about the key difference between a respirator and a mask.
By definition, respirators are tight-fitting and rely on an adequate seal to protect wearers from microscopic aerosols, particulates, fumes, vapours, and gases.
Face masks, on the other hand, are not tight-fitting and do not create a seal between the face and the mask. Masks are typically used in healthcare or by the general public to prevent the transmission of infectious droplets (droplets are relatively large particles such as those generated by sneezing/coughing). Face masks do not protect against submicron aerosols, particles, dust, vapours, fumes, etc.
Respirators can be disposable or reusable (aka elastomeric). A common mistake people make is thinking that only reusable respiratory protective equipment can be classified as a respirator. But that's incorrect. Tight-fitting disposable masks are respirators too!
Most people refer to reusable respirators as masks and that's OK. But it's important to understand that there is a difference - especially if you're a PCBU or health and safety manager looking after the respiratory protection program for your workplace.
All respirators, whether disposable or reusable, should not be worn by people with facial hair and they have to be fit tested to ensure they fit the wearer properly.
How Do Respirators Work?
Generally speaking, respirators work in one of two ways. The first is the removal of contaminants from the air through a filter or cartridge. These types of respirators are called air-purifying respirators (APRs).
Air-purifying respirators use particulate filters (to catch dust and other particles such as viruses) and/or gas/vapour cartridges to protect the wearer from - you guessed it - chemicals, gases and vapours. The type of filter/cartridge needed depends on your workplace exposures.
The second way that respirators can protect is by supplying clean air from another source (such as a tank or wall supply). These types of respirators are called air-supplied respirators (think of firemen with their air tanks on their backs).
Whether you require air-purifying respirators or supplied air respirators depends on your workplace hazards. A risk assessment is required and a qualified professional should be involved in the selection of RPE.
Types of Respirators
Credit: Centers for Disease Control and Prevention
Elastomeric Respirators
An elastomeric respirator is a type of reusable respiratory protective device that is designed to provide protection against airborne contaminants. Unlike disposable respirators, which are meant for single-use, elastomeric respirators are made from durable materials such as rubber or silicone, allowing them to be cleaned, decontaminated, and reused multiple times.
Elastomeric respirators have a flexible facepiece that conforms to the wearer's facial contours, creating a secure seal. They come in half-face (covering nose and mouth) and full-face (covering nose, mouth and eyes) styles. The type you need to wear should be determined by a risk assessment and, in some cases, personal preference.
To protect you from airborne contaminants, air-purifying respirators are equipped with replaceable filters, cartridges, or canisters that capture and filter out harmful particles, gases, or vapors. These filters are selected based on the specific hazards present in the environment and the level of protection required.
When wearing an elastomeric mask with a supplied air source, filters aren't required. And supplied-air respirators are typically only available as full-face masks.
Full-face and Half-face Air-purifying Elastomeric (aka reusable) Respirators
Elastomeric respirators, compared to disposable respirators, can be a more cost-effective and environmentally friendly option for individuals and organizations that require respiratory protection. They're often used in industries such as construction, mining, manufacturing, and engineering.
Elastomeric respirators are considered "tight-fitting" respirators and can't be worn by people with facial hair (facial hair breaks up the seal; read more about that here).
Tight-fitting respirators must be fit-tested to ensure there is no leakage around the facepiece and the face.
Fit testing, maintenance, and cleaning are essential to ensure the effectiveness and longevity of elastomeric respirators.
Disposable Filtering Facepiece Respirators
Disposable respirators, also known as filtering facepiece respirators (FFRs), are designed for single-use applications. They have to be discarded after each use. A general rule of thumb is that FFRs should not be worn longer than 4 consecutive hours or if they become damp, soiled or damaged while wearing.
Disposable respirators are made of various materials, including non-woven fibers, and are often equipped with an adjustable nose clip for a secure fit. They come in different levels of protection based on their filtering efficiency against airborne particles.
In Australia, you'll most commonly see P1, P2, and N95 disposable respirators. P1 and P2 are Australian standard filtration levels while N95 is an American standard. As far as protection goes, P2 and N95 are essentially the same.
Filtering facepiece respirators work by using multiple layers of specialized filtering materials to capture airborne particles. As the wearer inhales, air passes through these layers, where particles are trapped through mechanisms like impaction, diffusion, and electrostatic attraction.
Disposable respirators come valved and unvalved. Masks with valves are easier to breathe through and are often used in industries such as construction. In healthcare, however, the mask should not have a valve to prevent the wearer from exhaling potentially contaminated aerosols (such as viruses).
Disposable respirators are considered "tight-fitting" just like reusable ones. They can't be worn by people with facial hair and have to be fit-tested.
Powered Air-Purifying Respirators (PAPRs)
Credit: JSP Credit: 3M
Powered air-purifying respirators (PAPRs) provide a continuous flow of filtered air to the wearer. Unlike negative pressure respirators, PAPRs use a motorized, battery-powered blower to draw air through filters, delivering clean air to the user. This type of respirator is particularly useful in environments where contaminants are present in high concentrations or where negative-pressure respirators might not provide sufficient protection.
Some people find that PAPRs offer enhanced comfort, especially during prolonged use, as they reduce the effort required for inhalation. They also accommodate various types of headgear and can be paired with hoods or helmets for full head protection.
PAPRs can be tight-fitting or loose-fitting (like the ones in the photo above). Loose-fitting PAPRs can be worn by people with facial hair (as long as the beard is short/trimmed) and they don't require fit testing. Loose-fitting PAPRs are often the only option for people who must wear RPE but can't/won't shave.
Air-Supplied Respirators
Air-supplied respirators are the most comprehensive respiratory protection option. They deliver a clean air supply from a remote source, ensuring that the wearer breathes uncontaminated air at all times. These respirators are often used in environments where extremely hazardous contaminants are present, or where oxygen levels are deficient.
Air-supplied respirators include airline respirators and self-contained breathing apparatuses (SCBAs). Airline respirators are connected to an external air supply through hoses, while SCBAs carry their air source on the wearer's back. These respirators offer a high level of protection, making them suitable for emergency response teams and specific industrial settings.
The standard of the supplied air should adhere to the minimum requirements defined in AS/NZS 1715. This specification outlines acceptable thresholds for oxygen, carbon monoxide, carbon dioxide, oil, moisture, and pressure within supplied-air respirators.
Never use general-purpose air compressors to provide breathing air. This can result in air contamination with hazardous substances and gases, including carbon monoxide.
How to Select RPE
Selecting the right RPE is critical to ensure safety in environments where employees are exposed to airborne contaminants, hazardous particles, gases, or vapors.
This section is just a brief overview of how to select RPE. A comprehensive risk assessment must be done in a workplace to ensure you're choosing the right combination of masks and filters. A competent person must be involved in the selection process.
For more information on particulate filters and gas/vapour cartridges, check this out: Quick Guide: Respirator Filters and Cartridges.
In Australia (as well as the US, Canada, UK), the proper way to select RPE involves using assigned protection factors (APFs) and workplace exposure standards (WES) to make informed decisions.
Many other factors go into the selection of RPE including which airborne contaminants you're exposed to, workplace conditions, work areas, user acceptability and comfort, cost, maintenance, etc. The AS/NZS 1715:2009 goes into more detail about RPE selection. Familiarise yourself with this Standard!
Also - be sure you're using RPE and filters that are AS/NZS 1716:2012 certified or its equivalent (such as NIOSH in the USA). This Standard specifies requirements, performance and testing criteria for the manufacture of RPE and filters. Don't get confused - AS/NZS 1716:2012 is different from AS/NZS 1715:2009. (Learn more about standards and protocols here).
For disposable respirators, the certifying body - such as AS/NZS 1716:2012 or NIOSH - is printed either on the front of the mask or on the straps. If you don't see the stamp, the mask is not legit.
For reusable respirators, the certifying body is usually printed on the packaging.
We recommend checking out this 'Buying Guide' (for disposable respirators) from RESP-FIT: https://respfit.org.au/buying-guide/
Assigned Protection Factors and Workplace Exposure Standards
Let's start by defining what an assigned protection factor (APF) is.
Different combinations of respirators and filters are given an assigned protection factor. The APF is a number that indicates how much protection that respirator is capable of providing if the respirator is fit tested and the wearer is trained on how to use and wear it properly.
In Australia, APFs are typically denoted at 10, 50, 100 and 100+.
For example, disposable P2 respirators have an APF of 10. This means they reduce workers' exposure to airborne contaminants by at least a factor of 10 if used properly. To put it another way, if the airborne contaminant is 10X the workplace exposure standard (we'll get to that soon), you would have to choose a respirator/filter combo with an APF of at least 10.
Next up - workplace exposure standards.
The workplace exposure standards (WES) are a comprehensive list of chemicals and particles with maximum exposure limits associated with them. The list is developed and maintained by Safe Work Australia. You can access it here.
If airborne contaminants appear on this list, then it's prudent to monitor the air levels in your workplace to ensure you're not exceeding the WES. Whether air monitoring is a legal requirement or not depends on your industry and state requirements.
Using APF and WES to Choose Respirators
When choosing respirator/filter combinations using APFs and WES, you have to know the actual air levels of contaminants present in the workplace. This can only be achieved with air monitoring (usually conducted by an occupational hygienist).
Here's how to do it.
Air levels / WES = Minimum Assigned Protection Factor
PRACTICAL EXAMPLE:
Recent air monitoring at a construction site shows respirable crystalline silica levels of 1 mg/m3 (time-weighted average). This is above the WES standard of 0.05mg/m3 (it's 0.020 in Victoria).
Let's say we're in Victoria.
Actual Concentration (0.50mg/m3) / WES (0.02 mg/m3) = 25
Refer to the chart below. You'll need to choose RPE from the 'up to 50' row. At a minimum a full-face respirator with a P2 filter is required (as a non-powered respirator option).
It's important to note that you can attach P3 filters on half-face respirators, but they will effectively be P2 level of protection. P3 filters only achieve P3 level of protection when they are on full-face respirators.
Now let's look at an example where gas/vapours are the hazard.
PRACTICAL EXAMPLE:
Recent air monitoring at a leather goods manufacturer revealed xylene levels to be 125ppm. The WES is 80ppm.
Actual Concentration (150ppm) / WES (80ppm) = 1.875
Refer again to the chart below. You'll need to choose RPE from the 'up to 10' row to determine what Class filter you need. In this case, a half-face reusable respirator with a Class 1 gas/vapour cartridge should suffice.
You also need to know what colour cartridge you need as it relates to the hazard. See the graphic below this one. For xylene, the brown 'A' cartridge would likely be an appropriate choice.
Credit: 3M
Here's what an A1 cartridge looks like:
Credit: Maxisafe
If your air contaminants aren't quantified, it can be tricky to choose the right combination and you wouldn't be able to use the formula above to determine the APF.
If there are unknown contaminant levels or levels that are IDLH (immediately dangerous to life or health) or oxygen levels <19.5%, you will likely be using air-supplied respirators. Expert consultation should be sought and a comprehensive risk assessment must be conducted.
Again, we can't stress this enough. It's imperative to consult with professionals, such as certified occupational hygienists, who understand airborne contaminants, air monitoring and selecting appropriate RPE.
Fit Testing
To comply with the AS/NZS 1715:2009, tight-fitting respirators must be fit-tested to ensure there is an adequate seal between the facepiece and the wearer's face.
Fit testing is not new. This requirement has been around for decades as part of a comprehensive respiratory protection program. But in Australia, it hasn't always been enforced.
There are two methods for conducting respirator fit testing: quantitative fit testing and qualitative fit testing.
Quantitative Fit Testing
Quantitative fit testing uses a machine (usually a PortaCount or Accufit) to measure the actual leakage of a respirator's seal, providing numerical data as to how well the respirator fits (this is called the fit factor). This test is done by challenging the seal of the respirator with naturally occurring, ultrafine particulates from the surrounding environment.
Quantitative fit testing is an objective measure of the seal so the results are inherently more accurate than qualitative testing.
There's also the CNP method which is less common.
Qualitative Fit Testing
Qualitative fit testing assesses the adequacy of the respirator seal and fit based on the wearer's sensory perceptions.
During qualitative fit testing, the person wears a respirator mask and is exposed to a test agent, most often saccharin or Bitrex. The wearer performs a series of movements and activities while wearing the mask, such as normal breathing, talking, and head movement. If the wearer detects the taste or irritation of the test agent inside the respirator, it indicates a potential leak, suggesting that the mask does not provide an effective seal.
The major downside of qualitative fit testing is the subjectivity of the test. Some people have trouble determining if they can actually taste the solution or not.
Qualitative testing can only be used on disposable and half-face reusable respirators. Full-face respirators must be tested using a quantitative method.
When to Fit Test
Fit testing must be undertaken when folks are initially issued their respirator and annually thereafter. If there are any significant facial changes due to weight loss/gain, surgeries, trauma, or dental work, they need to be retested.
It's important to note that you must wear the exact brand/model/size respirator you're fit tested on. If you change brands, models or sizes, you need to get another fit test on the new mask.
If you're looking for qualified professionals to conduct fit testing for you or your staff, we know a company we can refer you to :-)
Facial Hair and RPE
Credit: Canva Premium
At the heart of tight-fitting respirators is the ability to achieve an adequate seal between the facepiece and the wearer's face. Facial hair can significantly impact the seal of the RPE, leading to compromised protection against airborne contaminants.
Under the AS/NZS 1715:2009 (and all international standards), individuals must be clean-shaven in the areas where the mask's seal makes contact with the skin. Even a short beard or stubble can hinder the mask's ability to create a proper seal, allowing contaminants to enter the breathing zone.
For folks with facial hair who cannot (or will not) shave, there are options such as loose-fitting powered air-purifying respirators (PAPRs) or reassignment to areas where respirators aren't required (not always a feasible option)
Regular training and education for workers and supervisors about the implications of facial hair on RPE effectiveness are integral components of AS/NZS 1715:2009. This ensures that individuals understand the importance of maintaining a clean-shaven face for certain types of RPE and the rationale behind using specific equipment when facial hair cannot be removed.
Click here for more information about facial hair and respirators.
Capabilities and Limitations of RPE
Respiratory protective equipment should never be the only measure in place to protect yourself or your workers against dangerous airborne contaminants. RPE can help reduce exposure but never eliminates exposure.
When it comes to workplace health and safety, including respiratory protection (considered a type of personal protective equipment or PPE), many employers and health and safety managers refer to the hierarchy of controls when managing risks.
A Bit About the Hierarchy of Controls
Credit: NIOSH
The hierarchy of controls serves as a basic framework for effectively prioritizing risk reduction strategies in a systematic manner. This structured approach consists of five levels: elimination, substitution, engineering controls, administrative controls, and personal protective equipment (PPE).
Starting with the highest level of control, the hierarchy encourages the elimination of hazards wherever possible, followed by substituting hazardous processes or materials with safer alternatives. If complete elimination or substitution isn't feasible, engineering controls are introduced to isolate workers from potential risks, subsequently supported by administrative controls that encompass procedures and policies to regulate exposure. Finally, as a last line of defense, appropriate personal protective equipment is provided.
Sometimes, our clients express skepticism regarding the necessity of RPE due to its position as the final resort within this widely recognized hierarchy. The only time RPE is potentially not needed is when workplace exposure standards can be effectively met through the implementation of measures like engineering refinements, hazard elimination, or material substitution. Nevertheless, certain industries and contexts mandate the use of RPE at all times. Knowing the specific requirements of your industry and workplace is imperative.
We contend that a reimagining of the hierarchy of controls is overdue. Transforming the traditional inverted triangle into a more encompassing circle would underscore the significance of each preventive measure. In most scenarios, a combination of elimination, substitution, engineering, administrative protocols, and PPE is required for comprehensive risk management in many workplaces.
Even in situations where a particular component, say PPE, appears unnecessary, the responsibility falls upon the designated risk manager to discern its requirement through a thorough evaluation process and not simply because it's the last rung in the hierarchy.
Sorry for the digression.
Back to the topic at hand.
In a nutshell, RPE - when worn correctly and fit-tested - can provide excellent protection against airborne contaminants. Wearers must also be trained on how to use and maintain their RPE for it to be most effective.
But there are quite a few limitations too. RPE:
Must be worn correctly - and a seal check performed - every time. An undertaking that demands behavioral modification and consistency, a feat not always easily accomplished.
Is typically pretty uncomfortable to wear, especially when it's hot.
Can interfere with other PPE such as safety goggles. Not easy to wear with eyeglasses.
Can impede vision and speech.
Can't be worn safely by just anyone. People with certain medical conditions may not be able to wear RPE.
Just keep these things in mind when selecting and using respiratory protective equipment.
Cleaning, Storing, and Maintaining RPE
This section pertains to reusable respirators.
Cleaning
After each use, RPE should be cleaned according to manufacturers' instructions or established protocols. This typically involves wiping down the external surfaces with cleaning wipes, ensuring that any visible dirt, debris, or bodily fluids are removed. If a respirator is particularly grimy, most can be cleaned with warm water, neutral detergent and a soft brush. And disinfection can be achieved with diluted household bleach (again, follow manufacturers' instructions to avoid damaging equipment). After cleaning, allow to air dry.
Components such as facepiece seals, valves, and straps should be thoroughly inspected every time you clean RPE (and before each wear).
Proper cleaning not only promotes hygiene but also extends the service life of the equipment.
Storage
You can preserve the integrity of your respirator and filters by storing them properly. After cleaning, place your respirator/filter in a ziplock bag or storage container to shield from dust, moisture, and direct sunlight. Take care not to overcrowd or stack heavy items on top of RPE, as this can lead to deformation and degradation, especially of rubber or silicone facepieces.
PS: throwing your respirator and filters in the back of your ute does not count as proper storage :-)
Maintenance
Routine maintenance of reusable RPE is critical to ensure its functioning optimally. This involves conducting regular inspections, beyond just pre-use checks, to identify any issues that might compromise the equipment's performance. Replace damaged or worn-out parts promptly, adhering to manufacturer recommendations. Straps, valves, and gaskets are components that might require replacement or maintenance due to wear and tear.
Air-supplied and powered air respirators will likely require more involved maintenance and upkeep.
Scheduled intervals should be established, and records of maintenance activities kept for compliance and accountability.
Breathe Easy. We're at the End.
As you can see, there's a lot to know and learn about RPE!
A holistic approach that encompasses the standards set forth by AS/NZS 1715:2009, understanding the intricacies of RPE, selecting the right equipment, ensuring proper fit, addressing the issue of facial hair, and adhering to cleaning, maintenance, and storage protocols ensures a comprehensive and effective strategy for maximizing worker safety and respiratory health in your workplace.
Fit Test Victoria offers online and in-person Respiratory Protective Equipment courses. Call us for more details: 0428 630 109 or email info@fittestvic.com.au
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