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What you need to know: PPE and fit-testing

Blog Author Tarik Shembesh

Blog Date 18/06/2020

A dentist who is leading the fit-testing program in London's urgent dental centres, shares 10 things you need to know about fit-testing PPE and the dental practice.


Using the right personal protective equipment (PPE), including respiratory protective equipment (RPE), will help protect staff, patients and visitors during the pandemic. However, dentists have two important challenges in terms of PPE and COVID-19. The first is sourcing the right gear. The second is getting it correctly fitted.


Here are the 10 things you need to know about PPE and fit-testing:


1. Research and contacts can help you find the right PPE

The HSE guidelines and the BDA’s Returning to face-to-face care toolkit offer advice on the different masks available. I advise you not to opt automatically for the cheapest type and don’t necessarily go with the fastest delivery. If possible, try to get several different kinds of RPE if you can, so that your staff can be properly fit-tested.


We all hope that shortages will lift soon and PPE will become more readily available. In the meantime, speak to other practices and contact your usual PPE supplier. This pandemic is likely to last for some time, and I believe that if we communicate and coordinate our efforts, we can come together and learn from each other.


2. There are six different types of RPE

The six main types of respirators with particle filters are:


  • Disposable half mask/filtering facepiece
  • Reusable half mask
  • Full face mask
  • Powered half mask
  • Powered full face mask
  • Loose fitting powered facepieces (hoods). 

All tight-fitting facepieces (1-5) require fit-testing to ensure an adequate seal. Loose-fitting respirators do not need fit-testing as they do not require a tight seal.


3. Counterfeit and uncertified PPE is a big problem

PPE is in high demand right now and it has never been more expensive. However, while supply difficulties persist, counterfeit products are likely to proliferate. I urge you to be careful. Don’t get caught out. Only purchase PPE from reputable sellers and look out for a genuine CE mark.


In the rush to get PPE to protect their patients and staff, dentists may end up buying uncertified products, such as this KN95 mask. Do not do this. These masks are available for purchase, but they are not CE marked and therefore not fit for use as PPE.


4. Fit-testing is essential and there’s two different kinds 

The most common method of fit-testing is the qualitative test. This involves a relatively straightforward test and relies on the person’s taste perception. I will go into detail about how this is carried out below.


The quantitative test by contrast uses a particle-counting machine to record the ambient particle count both outside of the respirator and within the respirator while it is fitted. This latter test is carried out less often, because of the expensive machinery required. Either form of testing has been proven to be adequate by HSE, you don’t need to carry out both. The HSE website has advice and training materials on fit-testing respirator masks.


5. Most fit-testing relies on your sense of taste 

During the first stage of the most common test, you test their sensitivity to taste. When fit-testing, you’re asked to put a hood over your head and to breathe through your mouth. A specific amount of aerosol is then sprayed into the hood until you signal that you can taste it.


Once you confirm that you can taste the aerosol, the fit-tester records the amount sprayed in and you’re allowed to take the hood off. You can drink water (though eat and drink nothing else) and are asked to wait for 30 minutes before the second half of the test. I often take this time to run through some training as specified in guidance by the HSE.


6. There is no one-size-fits-all RPE 

During the second half of the test, I work with the dentist/member of the dental team to assess which of the available RPE options they find most comfortable. This is like finding a pair of shoes. You’d never expect everyone in a dental practice to wear the exact same size and type of shoe. Similarly, it is unlikely that one particular model or size of RPE will fit everyone in a practice. Good contact between the skin and the face seal is needed, and a poor fit will substantially reduce the protection provided to the wearer.


Some people have medical conditions that restrict the types of RPE they can wear, such as asthma or allergies. Others may not be willing to shave facial hair for religious reasons and require alternative non-seal-based options.


7.  RPE needs to work for the tasks being performed 

The seal on the RPE also needs to work for the wearer as they perform their job. You need to consider multiple factors. What kinds of tasks will they be carrying out? Do they have glasses? What kind of loupes do they use? Correct fit-testing helps you and your practice figure out what kind of RPE suits them and the job they are doing.


During the final stage of the test, I ask them to wear their chosen RPE under the hood and I once again ask them to breathe through their mouth, while they perform motions to replicate the tasks they’ll need to undertake. I then spray in the aerosol again and ask the dentist to indicate if they can taste it. This may need to be done multiple times to ensure that the right RPE fit has been found.


8. Responsibility lies with both employer and employees  

Remember it’s the employer's responsibility to ensure the suitability and adequacy of the RPE. However, employees have a legal duty to use and maintain the RPE following the training and instruction provided and to report any defects or problems immediately. A good fit-tester will support you and your team to keep staff and patients as safe as possible during the ongoing pandemic.


9. Training is an essential part of fit-testing  

As part of the fit-testing and training, you should conclude the process with clarity on the following areas:


  • Why the RPE is needed and when to use it
  • The hazards, the risks and effects of exposure
  • How the equipment works and what it can and cannot do
  • How to correctly put on, wear and remove the equipment
  • How to get a good face fit if the RPE incorporates a face mask
  • How to carry out pre-use inspection and fit checks
  • How to clean and inspect RPE during and after use
  • How to store it and when to replace it
  • How to report any defects or problems.

If you’re unclear about any of the above, please double check with your fit-tester. The point of this session isn’t just about fitting PPE, It’s about safety and awareness. Make sure we’ve done our job so that you feel confident to do yours.


10. Professionalism and integrity are essential

Dentists are highly experienced in infection control and some may feel like they know much of this information already. However, as many of us are facing new challenges and using new protective equipment, we must take the time to properly familiarise ourselves with it and its proper use.


The validity of the fit-test relies on the training and professional integrity of the tester, as well as the person being tested. Some can find this a stressful process and so it is important to be calm and reassuring to help ensure that the answers given are honest.


Your fit-tester should challenge you to get the right fit. Only one dentist has asked me to “just sign me off” without a proper fit-test being completed. Thankfully, I believe that this lax attitude to safety is uncommon. Most dentists are trying, in quite difficult circumstances, to do the right thing by themselves, their staff and their patients.




Dr Tarik Shembesh

Fit2Fit Accredited Fit tester & Trainer
Respiratory Protection & Fit testing Lead, NHS England - London region
Director, Dakatra Ltd


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