What’s the Difference Between a Respirator Fit Test & Fit Check?

When it comes to wearing a P2 respirator, choosing a certified product is only part of the equation. For a tight-fitting respirator to provide its intended level of protection, it also needs to fit the wearer's face properly and form an effective seal.

This is where two terms often come up: fit testing and fit checking. They sound similar—and both relate to how well a respirator fits—but they serve very different purposes.

A fit test is used to determine whether a specific make, model, style and size of respirator is capable of providing an adequate fit for an individual wearer. A fit check, on the other hand, is something the wearer performs each time they put on their respirator to check that it has been positioned correctly and an appropriate seal has been achieved.

In other words, passing a fit test doesn't mean you can assume your respirator is fitted correctly every time you wear it. How you position the respirator, adjust the straps and nosepiece, as well as factors such as facial hair or other PPE, can all affect the seal on any given day.

Why does respirator fit matter in the first place?

A P2 respirator works by filtering airborne particles as you breathe. But for that filtration to work as intended, the air you inhale needs to pass through the respirator's filter material—not take an easier route through gaps between the respirator and your face.

That's why fit is such an important part of respiratory protection.

Tight-fitting P2 respirators are designed to form a seal against the face. If that seal isn't adequate, unfiltered air may leak around the edges of the respirator, potentially reducing the level of protection you receive—even when the respirator itself meets the relevant P2 performance requirements.

Common areas where leakage may occur include:

• Around the bridge and sides of the nose

• Along the cheeks

• Around the sides of the respirator

• Under the chin

A number of factors can affect this seal. The respirator may simply not be the right shape or size for your face, or it may have been positioned incorrectly. Facial hair, incorrect strap placement and interference from other personal protective equipment (PPE) can also prevent the respirator from sitting against the face as intended.

This is also why there isn't necessarily one P2 respirator that will fit everyone. Faces vary in shape and size, and two certified P2 respirators with similar filtration performance may fit the same person very differently.

Importantly, certification and fit aren't the same thing. P2 certification indicates that a respirator meets applicable performance requirements, while fit testing helps determine whether a particular respirator can achieve an adequate fit on an individual wearer.

What is a respirator fit test?

A respirator fit test is a formal assessment used to determine whether a particular tight-fitting respirator can achieve an adequate seal on an individual wearer's face.

Importantly, you aren't simply being fit tested for "a P2 respirator" in general. The result applies to the specific make, model, style and size of respirator used during the test. Passing a fit test with one P2 respirator doesn't automatically mean another brand, model or size will provide the same fit.

During the test, the wearer puts on the respirator and performs a series of movements or exercises designed to reflect movements that may occur while the respirator is being worn. Depending on the testing method, this can include activities such as normal and deep breathing, turning the head from side to side, moving the head up and down, and speaking.

There are two main approaches to fit testing:

Qualitative fit testing:

A qualitative fit test is a pass-or-fail test that relies on the wearer's ability to detect a test substance while wearing the respirator.

A test agent is introduced around the wearer while the respirator is being worn. If the wearer can detect the substance during the test, it may indicate that it has entered through a leak in the face seal and the respirator has not achieved the required fit for that test.

Quantitative fit testing:

A quantitative fit test uses specialised equipment to objectively measure how well the respirator seals against the face.

Rather than relying on the wearer's senses, the equipment measures leakage and calculates a numerical result known as a fit factor. This provides an objective measurement that can be compared against the required pass level for the respirator being tested.

Whichever method is used, the purpose is essentially the same: to establish whether that particular respirator is suitable for that particular wearer.

If a respirator doesn't pass the fit test, another size, model or style may need to be tried until an appropriate fit can be achieved.

When should you have a fit test?

A fit test isn't something that should only happen once at the beginning of your employment and then be forgotten. Your respirator, your face and even the equipment available in your workplace can change over time, so fit testing needs to be repeated in certain circumstances.

According to SafeWork NSW, fit testing for tight-fitting respirators should be carried out:

• Before wearing a tight-fitting respirator for the first time.

• Whenever you're issued a new make or model of respirator. A respirator that looks similar to your previous one may fit your face differently.

• When your facial characteristics change in a way that could affect the seal. This may include significant weight loss or gain or other changes to facial features.

• At least annually, even if you continue to use the same respirator and haven't noticed an obvious change in fit.

Other changes, such as facial surgery or significant dental changes, may also affect the way a respirator sits against the face and can be a reason to reassess fit. NSW Health, for example, identifies changes such as loss of teeth or dentures, significant weight changes and facial surgery as reasons for health workers to undergo fit testing again.

What is a respirator fit check?

A respirator fit check—also commonly called a user seal check—is a quick check performed by the wearer every time a tight-fitting respirator is put on. Its purpose is to check that the respirator has been positioned correctly and that an adequate seal has been achieved before entering an area where respiratory protection is required.

Unlike a fit test, a fit check doesn't determine whether a particular respirator model or size is suitable for your face. That should already have been established through fit testing. Instead, the fit check helps confirm that your respirator appears to be sealing correctly this time you put it on.

The distinction can be summed up simply:

• Fit test: Does this particular respirator fit my face?

• Fit check: Have I put this respirator on correctly and achieved a seal this time?

A fit check may help identify problems such as incorrect positioning, poorly placed straps, an inadequately moulded nosepiece or something interfering with the sealing surface. If you notice air leaking around the edges during the check, the respirator may need to be repositioned and checked again.

The exact method used to perform a fit check can vary depending on the respirator's design, so always follow the manufacturer's instructions for the specific respirator you're wearing.

Types of respirator fit checks

There are two commonly used approaches to checking the seal of a tight-fitting respirator: a positive-pressure fit check and a negative-pressure fit check. The method you use will depend on the design of your respirator.

1. Positive-pressure fit check

Used for: N95s, P2 masks and most disposable respirators without exhalation valves.

A positive-pressure fit check is designed to identify whether air is escaping around the edges of the respirator when you breathe out.

Depending on the respirator design, the general process may involve:

• Place your hands over the respirator as directed, taking care not to press or distort the facepiece against your face.

• Gently exhale to create slight positive pressure inside the respirator.

• Pay attention to whether you can feel air escaping around the edges, particularly around the nose, cheeks and chin.

• If you don't detect leakage and slight pressure builds inside the respirator, this can indicate that a seal has been achieved.

• If you feel air escaping, reposition the respirator, adjust the straps and nosepiece where applicable, and perform the check again.

2. Negative-pressure fit check

Used for: Reusable elastomeric respirators and masks with exhalation valves.

A negative-pressure fit check instead looks for air entering around the face seal when you breathe in.

Depending on the respirator, the general process may involve:

• Cover the respirator's filter surface, filter cartridges or air inlets as directed for that particular design.

• Gently inhale to create negative pressure inside the respirator.

• With some respirators, you may notice the facepiece draw slightly inward towards your face.

• Hold briefly and check whether you can feel air entering around the nose, cheeks, chin or other parts of the seal.

• If air leaks around the edges, reposition or adjust the respirator and repeat the check.

Always follow the manufacturer's fit-check instructions

These steps provide a general explanation of how positive- and negative-pressure fit checks work, but they shouldn't be treated as universal instructions for every P2 respirator.

Respirators differ in their shape, filter construction, valves and other design features, so always check the manufacturer's instructions for the correct fit-check procedure for your specific make and model.

Fit test vs fit check: At a glance

The easiest way to remember the difference is that a fit test helps determine which respirator fits you, while a fit check helps confirm you've put it on correctly each time. 

 

Facial hair: Why it matters for both

Facial hair can have a significant impact on the fit of a tight-fitting P2 respirator. For the respirator to form an effective seal, its sealing surface needs to sit directly against the skin. Hair that sits between the respirator and the face can create small gaps that allow air to leak around the filter.

This doesn't only apply to full beards. Depending on where the respirator seals against your face, stubble, moustaches, sideburns or other facial hair that crosses the sealing area may also interfere with the fit.

Facial hair matters for both fit testing and fit checking:

• During a fit test: Facial hair crossing the respirator's sealing surface can prevent an adequate fit from being achieved. For tight-fitting respirators, the wearer should be clean-shaven where the respirator seals against the face at the time of testing.

• During everyday fit checks: Passing a fit test while clean-shaven doesn't mean the same respirator will continue to seal adequately if facial hair is later allowed to grow across the sealing surface. The conditions under which the respirator is worn still matter each time it is put on.

It's therefore not simply a question of whether you have facial hair, but where that hair sits in relation to the respirator's sealing surface. A moustache or other facial hairstyle that remains completely inside or outside the sealing area may not interfere with the seal, whereas even relatively short growth directly beneath the sealing surface can be a problem.

Trying to compensate by tightening the straps more firmly isn't a reliable solution. The respirator still needs unobstructed contact with the skin in the areas designed to form the seal.

If facial hair can't be removed for medical, religious, cultural or other reasons, speak with your workplace or respiratory protection program administrator about alternative respiratory protection that doesn't rely on a tight face seal, where appropriate for the hazard.

Can glasses and other PPE affect the fit?

P2 respirators are often worn alongside other personal protective equipment, particularly in healthcare, construction and industrial settings. However, other PPE shouldn't interfere with the respirator's position or the seal between the respirator and your face.

Glasses are a common example. The arms or frames of prescription or safety glasses should not sit underneath the respirator's sealing surface. Glasses should generally sit over the respirator rather than between the respirator and your skin, and they shouldn't pull, push or distort the respirator from its correct position.

Other PPE that may potentially interfere with respirator fit includes:

• Safety glasses and prescription glasses

• Protective goggles

• Face shields

• Hard hats and other head protection

• Hearing protection

• Hoods or protective clothing worn around the head and face

The issue isn't necessarily the PPE itself, but whether wearing it changes the position of the respirator or interferes with its sealing surface, straps or other components.

For example, goggles that press down heavily on the top of a disposable P2 respirator could potentially alter how it sits around the nose. Similarly, straps from other PPE shouldn't displace the respirator's head straps or cause the facepiece to shift while you're working.

Where multiple pieces of PPE need to be worn together, they should be checked for compatibility as a complete setup, rather than considering each item separately. Your workplace's respiratory protection or PPE procedures should take this into account when selecting equipment.

How to choose a P2 respirator that fits you

There isn't one P2 respirator that will fit everyone equally well. Faces vary in size, shape and facial features, which means a respirator that forms an effective seal on one person may not provide the same fit for someone else.

Some factors that can differ between P2 respirators include:

• Size: Some respirators are available in multiple sizes to accommodate different face dimensions.

• Shape: Cup-shaped, flat-fold and other respirator designs can sit differently across the nose, cheeks and chin.

• Nosepiece: Adjustable nose clips and different nose-foam designs can influence how the respirator sits around the bridge of the nose.

• Strap design and positioning: Head straps help hold the respirator in its intended position and should be worn exactly as instructed by the manufacturer.

• Sealing surface: Different shapes, materials and edge designs may feel and fit differently against the face.

• Valved or non-valved design: An exhalation valve may affect comfort and suitability for particular environments, although having a valve doesn't mean the respirator will necessarily fit you better.

For workplace respiratory protection, fit testing is the appropriate way to determine whether a particular make, model, style and size of tight-fitting respirator provides an adequate fit for an individual wearer. Simply trying on a respirator and deciding that it feels comfortable isn't a substitute for fit testing.

This is also why workplaces may need to provide access to more than one respirator model or size. If one P2 respirator doesn't achieve an adequate fit, another design may be more suitable for that person's facial characteristics.

Once you've identified a respirator that fits through appropriate fit testing, remember that the job isn't finished. Perform a fit check every time you put it on and follow the manufacturer's instructions for correct positioning, strap placement and seal checking.

Need a respirator fit test?

If you or your team use tight-fitting respirators in the workplace, Aussie Pharma Direct offers accredited respirator fit testing services to help ensure the respirators you rely on are suitable for the individual wearer.

For added convenience, our fit testing team can come directly to your workplace to conduct testing for your staff, making it a practical option for businesses with multiple employees requiring fit tests. Alternatively, you can book an appointment to have your fit test completed at our store.

You can find more information about the service, what to expect and how to arrange your booking on our Respirator Fit Testing Service page.

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