Reducing the risks of Airborne Pathogens with Air Disinfection technology – fact or fiction?


  Posted by: Dental Design      9th August 2020

As the UK’s dental practices look to re-open their doors to patients, there is a significant level of uncertainty over what the new normal of dental care will look like. With the spotlight focussing brightly on the issues of AGPs, the requirement for comprehensive PPE and procedures to mitigate the risks and prepare the surgery for the next patient have been considered and recorded in detail. However, little focus has been placed on one of the newest technologies that has been proven to significantly reduce the risks from harmful airborne pathogens – that of plasma air-disinfection.

Although very little has been quoted in the latest ‘Back to Practice’ guidance about air treatment, published by the likes of the OCDO and FGDP, there are a raft of technologies that have recently been placed on the market that make various claims concerning their abilities to reduce the risk from harmful airborne pathogens that can be produced during AGPs.

With new technologies that have yet to be fully understood, the claims being made, including being tested against Covid-19, can often look very compelling and at face value can appear to provide the ideal solution to the challenges being experienced. In the case of coronavirus and the significant risks to human health, it is vital that any technologies that are placed on the market have the necessary proof and evidence to substantiate the claims being made. It is especially important that when it comes to Covid-19, products have been tested correctly, according to all the relevant protocols and acceptable surrogates – claims that a product has been tested directly against Covid-19 can be seriously misleading.

For the risks we face today, and indeed in the future, it is of vital importance that the dental team understands which technologies satisfy the claims being made of them. Without the supporting proof and evidence, decisions can easily be made based purely on misinformation. Facts can get diluted and confused with opinion, making it difficult for dental professionals to understand the situation fully and therefore, could result in making an incorrect decision for their staff and their patients.

Appreciation for the importance of air disinfection in the surgery has risen sharply in dentistry in recent months, with many practices beginning to see the treatment of the air they are breathing as one of the solutions required to manage the new cross-infection risks.

Interest in the new technologies introduced to help reduce the level of airborne contaminants, as a result of the effects of AGPs, has seen a massive spike, with many providers offering ‘tried and tested’ solutions. However, the lack of knowledge and the quality of the information being communicated mean a number of important questions relating to the effectiveness of the technologies employed in these products, need to be understood and addressed. Indeed, the advice recently published by the OCDO – ‘Standard Operating Procedure, Transition to Recovery’ – highlights some of the inadequacies of two of the most commonly employed technologies – filtration and UV light.

Myth #1 UV light is the best way to kill pathogens

Ultraviolet (UV) light has long been shown to reduce bacterial contamination.[i] Some studies have also suggested that UV light could be used successfully against coronaviruses.[ii] However, although shown as a practical method for treating liquids, it is not a particularly effective method for the treatment of air.

The fact that UV light sources degrade over time and the attraction of dust and debris acts as a shield to impair the performance of the UV light, makes this technique unreliable and even ineffective in practical situations. This limitation will also be amplified in air treatment systems that operate at the higher fan speeds required to provide the claimed ACH performance – the time that pathogens will be exposed to the UV light, vital for effective destruction, is unlikely to be sufficient.

In addition, UV light can produce ozone (O3) gas as a by-product, which can build up in unventilated rooms and is known to be harmful to human health, in particular a cause of respiratory problems. And, from a technical perspective, as UV light sources degrade over time they need replacing, adding to the whole-life-cost.  

As such, air disinfection technologies that employ UV light need careful consideration.

Myth #2 All you need is a HEPA filter to trap harmful micro-organisms

High Efficiency Particulate Air (HEPA) filters are designed to trap harmful pathogens and particulates in order to remove them from the air being treated. While they do this effectively, they do not destroy the micro-organisms – in fact, one study found that certain pathogens could survive within a HEPA filter for up to 6 days.[iii] These filters are also limited in that they can only effectively capture particles down to 0.3 microns in size. As viruses are often smaller than this, typically between 0.01 and 0.1 microns in size, HEPA filters are widely ineffective against this group of pathogens.[iv]

In addition, HEPA filters can become colonised by micro-organisms which may be released back into the air upon saturation of the filter fibres. For this reason, HEPA filters require constant and careful monitoring to ensure they do not become unknowingly saturated and in-effective. Over the life of a unit that employs filters, the additional cost of ongoing replacement will need to be accounted for.

Myth #3 Plasma technology is ineffective against viruses

Plasma has been proven in many laboratory and clinical studies to kill airborne viruses,[v] making it a highly successful agent for the decontamination of all micro-organisms, especially in the healthcare environment.

When utilised in air disinfection technology, plasma of the ultra-low energy, dielectric barrier discharge type is designed to ensure that all airborne pathogens are destroyed without the production of any by-products, especially those that are known to be harmful to health.

In addition, plasma air disinfection units can, if required, be used continually – 24/7. This level of continued operation, both day and night, has been shown as the best way to create the safest possible environment for practitioners and patients alike. Furthermore, the ability of plasma units to work continually to reduce the ongoing level of air contamination to an absolute minimum, offers a significant benefit in terms of the reduction in time required for the regular cleaning and disinfection of the room.

A market-leading solution

To make the very most of air-disinfection technology in dentistry, it’s important to work with manufacturers and suppliers that have the necessary evidence and proof to support the claims made of their products. Not only does this ensure that the equipment you are investing in will destroy harmful airborne pathogens, it also gives you a level of confidence and peace-of-mind that it is fit for use in the dental practice, one of the most demanding workplaces in the world.

The Novaerus Air Disinfection systems from Eschmann employ patented, ultra-low energy, dielectric barrier discharge plasma to ensure complete destruction of all harmful pathogens, including coronaviruses. Designed and CE marked specifically for use in the healthcare sector, Novaerus systems have been tested and proven in many laboratory and clinical studies as being 99.99% effective for the successful treatment of air.

Novaerus plasma technology produces no harmful by-products, especially ozone, is filter-free, compact and easily portable to help reduce the bio-burden of any rooms or surgeries within the practice. With zero filter costs, zero service costs and low running costs (with no maintenance required), it’s the ideal solution for dental practices to achieve and maintain a safe environment for staff and patients alike.

Stick to facts

As dental professionals, you will be used to analysing the research and implementing only evidence-based protocols and products. This ensures the safety and effectiveness of the dental procedures you perform for your patients. It’s even more important to take the same approach when it comes to re-enforcing your cross-infection control procedures, especially today.

There is a lot of information circulating about air disinfection technologies. It’s important you ask the right questions so that when you are ready to invest, you will be fully aware of which technologies are proven to be effective at helping to ensure the health and safety of your staff, your patients and, of course, yourself.


For more information on Eschmann’s range of air disinfection and instrument decontamination equipment and consumables, please visit or call 01903 875787


Author – David Gibson, Marketing Manager Eschmann


[i] Qureshi Z, Yassin MH. Role of ultraviolet (UV) disinfection in infection control and environmental cleaning. Infect Disord Drug Targets. 2013;13(3):191‐195. doi:10.2174/1871526511313030007

[ii] Keil SD, Bowen R, Marschner S. Inactivation of Middle East respiratory syndrome coronavirus (MERS-CoV) in plasma products using a riboflavin-based and ultraviolet light-based photochemical treatment. Transfusion. 2016;56(12):2948‐2952. doi:10.1111/trf.13860

[iii] Mittal H, parks SR, Pottage T, Walker JT, Bennett M. Survival of microorganisms on HEPA filters. Applied Biosafety. 2011;16(3) DOI: 10.1177/153567601101600305

[iv] Helmbuch, Brian & Wu, Chang-Yu & Wander, Joseph. (2009). Viral Penetration of High Efficiency Particulate Air (HEPA) Filters (PREPRINT). 39.

[v] Xia T, Kleinheksel A, Lee EM, Qiao Z, Wigginton KR, Clack HL. Inactivation of airborne viruses using a packed bed non-thermal plasma reactor. Journal of Physics D: Applied Physics. April 2019;52(25) DOI: 10.1088/1361-6463/ab1466

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