Respiratory Protective Equipment (RPE) is a form of Personal Protective Equipment (PPE), designed specifically to protect the wearer from breathing in harmful substances in the air.

RPE come in a variety of different styles, but at its most fundamental level, RPE can be divided into two categories:

Tight-fitting – RPE that relies on a seal being formed between the respirator mask and the user’s skin around the mouth and nose. All tight-fitting RPE must be face fit tested before use.

Loose-fitting – RPE that does not rely on a tight-fitting seal around the face, but on other means for protecting the wearer, such as powered air. Loose-fitting powered air devices use battery operated fans to force contaminated air through a filter and circulate it within a hood or helmet. Due to the force of the air flow, contaminated air cannot enter into the breathing area, keeping the user safe from harm.

Disposable respirator masks are single-use filtering devises, sometimes referred to as a filtering facepieces. Most disposable respirator masks are particle filters – either P1, P2 or P3.

Reusable half-mask respirators are reusable filtering devises that can be reused, often with interchangeable filters to cover a variety of hazards. Covering only half of the user’s face allows for full visibility but no eye protection.

Full-mask respirators are filtering devises that can be reused, often with interchangeable filters to cover a variety of hazards. Covering the full-face provides eye protection, but can limit visibility and inhibit communication.

Powered air purifying respirators (PAPR) are reusable filtering devises that rely on a motored device to feed air through a filter into a hood/helmet. Powered air RPE can be either tight-fitting or loose-fitting depending on the make/model and protection factor required.

Breathing Apparatus are different to respirator masks in that they do not rely on purifying air through a filter. Instead, Breathing Apparatus (BA) provide clean air to the user from an independent source, e.g. an air cylinder or compressor.

For further information on respirator types, please see the HSE Respiratory Protective Equipment at Work – HSG53.

A variety of work activities may result in employees being subject to harmful substances in the air in the form of dust, mist, gas, fumes or air-borne pathogens.

The law states that employers should prevent or control their employees’ exposure to hazardous substances at work. Before RPE is considered, a number of other options should be explored, as outlined in the Hierarchy of Control.

However, if exposure cannot be controlled by other means, suitable and adequate RPE should be provided for the protection of health.

Work activities that could require the use of RPE include:

  • Clearing chemical spills
  • Cutting materials such as stone, concrete or wood
  • Handling of dusty powders such as flour
  • Performing aerosol-generating procedures (AGP)

This is far from an exhaustive list. If you are concerned whether or not you require RPE in your line of work, speak with your Health & Safety Officer, or get in touch.

Fit testing is a practical examination to ensure a tight-fitting respirator mask can properly seal around a wearer’s face and is therefore suitable for the individual.

As people and respirators come in a variety of different shapes and sizes, not every facepiece will fit every person. Therefore, it is essential that a person be fit tested per make/model of respirator mask, in order to confirm that a tight-seal is achievable. If a tight-seal is not achievable, that type of respirator will not provide it’s intended protection, leaving the subject vulnerable to harm or even death. 

Please note: a fit test will not assess whether a respirator mask is adequate for the situation, only that it is suitable for the wearer.

There are two standard methods of Fit Testing in the UK. The qualitative fit test (QLFT) which measures taste and the quantitative fit test (QNFT) which measures the volume of particles. QNFT can then be categorised into those that measure ambient particle count (APC) and those that measure controlled negative pressure (CNP).

QLFT and QNFT-APC are the most common forms of fit testing used in the UK.

ANY person who wears tight-fitting RPE in the workplace needs to be fit tested.

As well as this being a legal requirement, it is essential to ensure your and your staff’s safety.

In the UK alone, an estimated 12,000 deaths every year are attributed to respiratory illnesses linked to past exposures at work, with a further 18,000 new cases of work-related respiratory problems being reported every year.

If you cannot be fit tested, loose-fitting RPE alternatives are available that do not require fit testing.

Tight-fitting RPE relies on a good seal against the face to work – preventing contaminated air from entering the subject’s lungs.

It has been scientifically proven that facial hair of any kind under the seal of a tight-fitting respirator mask will interfere with its effectiveness, potentially rending the equipment ineffective and endangering the user’s health.

HSE guidelines state that a person should clean-shave no longer than 8-hours prior to the beginning of their shift to ensure their tight-fitting RPE is performing sufficiently.

With this in mind, it is not only essential that subjects being fit tested are clean-shaven, but also that they remain clean-shaven whenever they use tight-fitting RPE in the workplace.

If a person is unable to shave (e.g. for health or religious reasons), alternative forms of RPE such as loose-fitting powered air devices are available.


Fit testing, or Bitrex (if using the qualitative method) will not harm you or your baby.

However, fit testing involves prolonged gentle exercise, wearing a respirator and (if using the qualitative method) wearing a testing hood over your head. Depending on where you are in your pregnancy, this may be uncomfortable or unmanageable. If so, please speak with your tester.

For more information see this blog.

The quantitative fit test method (QNFT) measures the number of particles passing through a mask to assess the effectiveness of a specific piece of RPE on an individual.

This can be done either through measuring the ambient particle count (APC) as the challenge substance, or through measuring controlled negative pressure (CNP). In the UK, APC is the predominant QNFT method, using a PortaCount machine.

QNFT-APC uses a PortaCount machine to count the number of particles inside and outside the respirator mask while the subject undertakes a series of exercises, designed to mimic common strains on the seal of their mask. The difference between these two readings indicates the RPE’s Fit Factor detailing how much protection is given by the RPE. 

Accurate, detailed and suitable for all mask types, QNFT is ideal for Fit Testing those working in high risk areas. Due to their being no need for a sensitivity test during the procedure, QNFT-APC takes roughly half the time of the QLFT method per test.

Choosing the correct filter can be complex. For more information, please visit our filter guidance page.

If you have any doubts about whether you are using the correct filter, please get in touch.

The hierarchy of control (or hierarchy of hazard controls) is a system used to eliminate or minimise the exposure of employees to hazards in the workplace.

From most effective at the top to least effective at the bottom, the hierarchy details how hazards should be approached in the workplace:

  • Elimination – physically remove the hazard
  • Substitution – replace the hazard
  • Engineering controls – isolate people from the hazard
  • Administrative controls – change the way people work
  • PPE/RPE – provision of PPE/RPE

As you can see, RPE should only be used as a last resort in addition to other methods, or when said methods are not possible. This is because the danger of getting it wrong could result in discomfort, ill-health or even death.

A fit check – also known as a pre-use wearer-seal check – should be performed every time a tight-fitting respirator is put on to ensure it has been donned correctly. This process involves the subject placing their hands over the filter/inlet valve(s) and breathing in. If the respirator mask has been put on correctly, the subject will feel the respirator mask suck inwards toward their face.

A fit check is not an alternative to a fit test, as it does not properly assess the validity of the respirator’s seal.

Fit checking may vary depending on make/model of respirator. For further information, please refer to your respirator’s instruction manual.

Different makes and models of respirator will require different methods for storing, cleaning and maintaining. For specific instructions, please refer to your respirator’s instruction manual.

For general guidance on storing, cleaning, assembling and maintaining your reusable RPE, get in touch.

Different respirators offer different levels of protection to the wearer. A proper assessment of any respiratory hazard that requires the use of RPE should advise you on the level of protection needed to keep employees from harm.

The assigned protection factor (APF) is a rating that indicates how much protection an item of RPE is able to provide its wearer. An APF is calculated through laboratory testing to assess how much exposure the wearer is likely to receive from any harmful substance in the air while being worn.

For example, a respirator with an APF of 200 should mean that the wearer will be breathing in one-200th or less of the hazardous substance in the air, compared with had they not been wearing a respirator.

When choosing a respirator, it is essential to select a model that provides an APF above the value required.



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