Air Filtration of SARS-CoV-2 in Dental Surgeries

November 03, 2020 2 min read

Air Filtration of SARS-CoV-2 in Dental Surgeries


With regards to reducing the fallow time in a dental surgery, it is good to know that the IQAir Cleanroom 250 air purifier's effectiveness in controlling viruses has now been officially confirmed by the European accredited test institute Airmid Healthgroup in Ireland. 

The test report confirms that the IQAir Cleanroom 250 high-performance air cleaner achieved a 99.9% reduction of airborne viruses in less than 10 minutes in a room of nearly 30m3 - making it an ideal Dental air purifier.  On the highest speed setting, the viral load was reduced from above 2790 ng/m3 to below the detectable measure of 0.156 ng/m3 - a 99.99% reduction. 

The virus used in the test is the H1N1 virus, which is identical in size range to SARS-CoV-2.

Using the IQAir high-performance air purifiers to minimise viral pollution is particularly recommended after aerosol-generating treatments. The use of the IQAir Cleanroom 250 air purifier can protect both medical personnel and subsequent patients from severe viral exposure. This is particularly relevant in the context of COVID-19, as it seems likely that the level of the viral dose is one of the decisive factors in the significantly high rate of serious illnesses among medical personnel.  When compared to other population groups, and even at a young age, physicians and nursing staff seem to be more likely to suffer from - and suffer more seriously - from COVID-19.

On page 37- 38 of the CGD/FGDP COVID-19 Guidelines “Implications of COVID-19 for the safe management of general dental practice – A practical guide”  it states that mitigating measures may be implemented to reduce the fallow period of 60 minutes after high risk AGE (Aerosol Generated Exposure). 

"Ventilation methods" are deemed an accepted mitigation measures, however, the guideline seems hesitant to give a general recommendation for the use of HEPA air purifiers:

"Opening windows or the use of a single room air conditioning unit, or air conditioning system that has recirculation turned off (extraction only mode) will improve ventilation. Air purifiers / air cleaners containing a HEPA filter and/or other adjuncts have been suggested as supplementary measures. There is currently not enough evidence to say whether the use of these measures will result in reducing the clearance time of potentially infective aerosols, but this view may change as further evidence emerges." (p. 38)

This hesitation in recommending air purifiers, in general, is justified.  ‘HEPA' is unfortunately not a standardised term and even low-quality air purifiers can call themselves 'HEPA air purifier’, despite the fact that they are often not able to even achieve a 50% removal efficiency at 0.3 µm in real-life situations.  

The above-mentioned test report for the IQAir Cleanroom 250 high-performance air purifier, however, provides clear evidence that certain premium HEPA air purifiers (i.e. HEPA air purifiers that are individually tested and certified to achieve at least 99.97% efficiency at 0.3 µm) do offer a very significant reduction of aerosolised viruses in a very short time - namely 99.9% reduction in virus load in a 28.5 m3 room after less than 10 minutes - and therefore can reduce the clearance time of potentially infectious aerosols significantly.

This high performance, however, cannot be expected of every air purifier that calls itself a 'HEPA air purifier'. The IQAir Cleanroom 250’s individual tested, certified and guaranteed real-life efficiency of 99.97% at 0.3 µm makes the essential difference.


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