Frequently Asked Questions

Respiratory Protection in Dentistry

Use, selection, fit-testing, maintenance and FAQs.


Dental practices are under a legal obligation, under Control of Substances Hazardous to Health (COSHH), to adequately control the risk of exposure to hazardous substances where exposures cannot be prevented. That includes when an individual may be exposed to a public health hazard such as SARS-CoV-2, the virus that causes COVID-19. To an extent, the provision and use of personal protective equipment (PPE), including respiratory protective equipment (RPE), protects staff, patients and visitors. It is essential therefore that Dental Professionals all understand the obligations that they have surrounding use, selection, maintenance and proper fit-testing of any RPE being used. Professionals must make full and proper use of any control measures, including PPE provided by their place of work. General advice on the selection of RPE is covered in the HSE guidance. 

The basic principles of RPE are that it must: 

  • be adequate and provide the wearer with effective protection; 

  • be suitable for the intended use; 

  • be 'CE'-marked; be selected, used and maintained by properly trained people; 

  • be correctly maintained, examined and tested; 

  • be correctly stored. 

Understanding Respirators

Respiratory Protective Equipment (RPE) is a form of Personal Protective Equipment (PPE) that is used to protect the individual wearer against the inhalation of hazardous substances in the workplace air. This is distinctly different from a surgical mask, which is a fluid-resistant barrier that is not designed to protect the wearer. Even though some larger droplets may be prevented from penetrating a surgical mask, its main function is protecting the patient.

A respirator is designed to protect the wearer’s respiratory tract. It acts as an air-filtering device and requires a seal to optimally protect the individual wearing it. 

The most recent hazard affecting dental professionals is the SARS-CoV-2 virus that causes Covid-19. The virus can spread in droplets via three main modes: 

  • Direct or Indirect contact, 

  • Droplet spray e.g. coughing and sneezing  

  • Airborne transmission e.g. aerosols 

Why do I need RPE?

Self-protection from the SARS-CoV-2 includes following advice on repeated washing of hands and thorough cleaning surfaces. Dentistry has adopted such habits for many years, long before the global pandemic raised such awareness to the wider public. However, due to the nature of their field of work, ENT surgeons, opthalmologists, anaesthetists and dentists operate in positions where social distancing is largely impossible. Respiratory protection is a way of mitigating social distancing limitations. Additionally, there remains much debate on the potential of aerosols created from dental equipment transferring the virus. The science is still developing on this matter, but in the meantime, the assumption is that virus containing aerosols can be inhaled and potentially transmit the SARS-CoV-2 virus.

Can I utilise alternative methods of controlling an airborne hazard to avoid using RPE?

The routine use of rubber dam, high volume suction, ventilation and potentially even the use of air purifiers and negative pressure environments could substantially reduce the hazard. Current guidance has not suggested these additional measures of risk management are enough to render respiratory protection unnecessary.

What are the different types of RPE?

There are six main types of respirators with particle filters: 
1. Disposable half mask/ filtering facepiece(FF) 
2. Reusable half mask
3. Full face mask 
4. Powered half mask
5. Powered full face mask 
6. Loose fitting powered facepieces 
Loose-fitting respirators do not need fit-testing as they do not require a tight seal. All tight-fitting face-pieces require fit-testing to ensure an adequate seal.

What is “Adequate” and what is “Suitable” in RPE terminology?

 “Adequate” describes RPE that is appropriate for the hazard and reduces exposure to the level required to protect the wearer’s health. There are two main types of filters: particles or gas/vapour. In the current pandemic the virus SARS-CoV-2 is the hazard of concern and requires a particle filter. 

“Suitable” is ensuring that the RPE “is right for the wearer, task and environment.” Fit-testing is the recognised way of proving suitability.

The limitations of RPE

No respirator is 100% efficient. Recent research indicates that up to 50% of RPE used do not offer the assumed protection. The most common causes of RPE failure are leakage and incorrect donning. 

  • Leakage occurs: 

  • Through the filter between the face and facepiece 

  • If the wearer is not clean shaven 

  • Through the exhalation valve 

  • Through defects in the facepiece

  • Incorrect donning 

  • Hair caught between face and mask 

  • Mouldable nose strip (for disposables) not firmly shaped to the wearer 

Should we be wearing FFP2 or FFP3 masks when performing aerosol generating procedures (AGPs)?

The current guidelines surrounding filtering particle masks are in relation to the Workplace Risk Factor (WRF). There are a number of types of RPE designed to protect the wearer from a variety of hazards, and in relation to a variety of workplace situations, and that match the specific requirements of the wearer. In relation to dentistry, the latest guidelines from PHE (Public Health England) state that fit-tested FFP3 respirators should be worn in addition to other PPE such as long sleeve disposable gowns, gloves and eye protection. The World Health Organisation (WHO) recommends FFP2 respirators for AGPs. PHE has stated that in the absence of availability of FFP3 respirators, FFP2 respirators are an acceptable alternative. FFP2 respirators are also tight fitting facepieces so also fit-testing.

What is the difference between KN95, N95 and FFP2?

Whilst the filtering capability of the respirator will be similar, the EU standards test respirators on their ability to create a seal to the face. KN95 and N95 laboratory testing does not take into account inward leakage from the seal of the respirator. Unlike FFP2 and FFP3, KN95 masks are not tested with paraffin oil, which is thought to be the most appropriate simulation of the particle size of the SARS-CoV-2 virus.
KN95 and N95 masks are not eligible to be sold legally in the UK unless they have gone through an assessment and fast-tracking by the EU, at which point they would be re-classified as an FFP2 respirator.

Has the recent HSE announcement about KN95 respirators changed anything?

No. It was always illegal to sell KN95s what haven’t been through EU/UK fast-track standard testing.

How do I spot a fake?

Sadly, the personal protective equipment (PPE) market has become infiltrated with fake respirators, putting wearers at risk. As with any fake product, differentiating a fake from a genuine one comes with experience. Any respirator should have specified markings on it to state it conforms to EU/UK standards. 
1) Manufacturer name/logo 
2) EU standard number e.g. EN149:2001+A1:2009 
3) EU Certification mark: CE 
4) Notified Body Number (I.E. 2797) responsible for product certification next to CE mark 
5) Manufacturer model number 
6) Type of respirator e.g. FF-filtering facepiece, NR - non-reusable. R - reusable

Will wearing a respirator affect my ability to communicate with patients?

Yes to an extent. Inevitably the facial barrier will affect the tone of our voice and the facial expressions we portray. This has been of little relevance to industries where respiratory protection has been traditionally used. For healthcare providers delivering invasive treatments under local anaesthesia to conscious patients, communication with empathy is vital. Changes in practice will inevitably be required as well as changes in patient expectations.

Will wearing a respirator affect me detrimentally in any way?

Some wearers have reported claustrophobia, disorientation and difficulty in breathing. This may be a genuine inability to tolerate the facepiece or it may be a matter of time until the wearer becomes accustomed to it with increased experience in use. The facepieces are filtering devices rather than obstructive to airflow, therefore hypoxia is impossible.
Facial bruises are common on removing a tight-fitting facepiece that has been worn for some time.

How long can I realistically wear a respirator for?

Respirators can be clumpy and claustrophobic, although a wearer is likely to become more accustomed to using with time. It would be difficult to wear a respirator for more than an hour, partly due to the increased effort it tales to breathe, but also that the wearer may by then be tempted to touch and adjust the respirator and break the seal.

Are disposable respirators for single-use or sessional use?

Disposable respirators can be worn for as long as the seal is intact and the fabric of the filter is not soiled or becomes wet.  It would be reasonable to expect a healthcare professional working on a ward seeing multiple patients to be able to use a respirator over a session, however if the respirator is being used in an environment where there are clear long breaks between seeing patients, the wearer may decide to doff the respirator and start the next patient using a fresh one.
Wearing a clear shield full-face visor is likely to help to keep the respirator free from splatter and clean enough to use between patients.

Understanding fit-testing

It is a legal requirement that workers using tight-fitting respiratory protective equipment (facepieces/masks) are fit tested by a certified competent person, such as those accredited by the BSIF. A dental professional can be appropriately trained and supported through practical mentorship in safely gaining experience and competency in performing facepiece fit testing. Fit-testers must be indemnified to perform the task, and this service may be offered by existing professional indemnity policies, or through public liability insurance. The fit-tester must seek advice from their providers before embarking on cases.

Fit-testers should be competent in: 

  • assisting in the selection of adequate and suitable RPE 

  • examination of RPE and the ability to identify poorly maintained and poorly fitting facepieces 

  • ability to correctly fit a facepiece and perform pre-use wearer-seal checks

  • awareness of external factors that may affect the fit of the facepiece, or the fit test result

  • the differences between, and the appropriate use of, quantitative and qualitative testing methods

  • the purpose of the fit-test exercises

  • capabilities and limitations of the fit-test equipment

  • how to perform a correct fit-test 

  • awareness and knowledge of how to prevent and correct problems during fit testing 

  • interpretation of fit test results

  • an understanding of the differences between fit factor, workplace protection factor (WPF), assigned protection factor and nominal protection factor (NPF); 

  • an understanding of HSE ACOPs guidance that addresses fit-testing of RPEs

What are the legal frameworks?

COSHH has stipulated that RPE must be ‘face fit-tested using a suitable method’ and HSE has given guidance on this in the HSG53 and INDG479 documents. The ‘British Safety Industry Federation’ (BSIF), alongside HSE, has also created practical guidance in the form of the ‘Fit2Fit Companion’. It is a legal requirement that workers using tight-fitting respiratory protective equipment (facepieces/masks) must be fit-tested by a certified competent person such as those accredited by the BSIF. The law states that an individual performing fit-testing must be certified as competent by an accredited body, but not necessarily be accredited themselves. Users are encouraged to perform their own risk management strategies in this regard.
The law is clear about employers’ responsibilities. An employer must (as long as reasonably practicable) provide a safe working environment for employees and provide the required PPE for them at no cost to them.
Where the law is not clear, is whether self-employed associates are indeed that, or are they classified as employees. There has been case law on this matter, but not within the healthcare industry. The government has a useful online algorithm to help people anonymously decipher if they are employed or self-employed, but this is designed for HMRC purposes rather than for employment rights.
An employer will need to keep records of selection, maintenance and testing for all members of the team.

Where do I get fit tested?

The ideal way is to coordinate locally through professional networks, or alternatively, to look on the BSIF fit2fit website: where they have a list of all the accredited RPE fit-test providers. These providers have had to go through a rigorous accreditation process to demonstrate their competency. There are numerous fit-testers that are competent but not necessarily part of the fit2fit scheme. 

Fit-testing in dentistry is a new concept. Whilst there are a number of fit-testers listed on the fit2fit scheme, there are very few trained and accredited dental professionals. Dental professionals who are also fit-testers are likely to have an enhanced understanding of the fine detail of the respiratory protection needs of the dental professional in the confinement of the dental workplace and environment.