Air Purifiers

Air Purifiers and COVID – what’s the evidence?

The facts on transmission:

It is now recognised by the World Health Organisation (WHO) that aerosol transmission is more important than previously thought for transmission of SARS-CoV-2, a virus that measures approximately 0.12 microns.

When we breathe, sing, sneeze, or cough, we release respiratory droplets, ranging in size from about 100 microns (the thickness of a human hair) down to microscopic levels (1 micron). Typically, we emit only a few larger respiratory droplets, which can only travel about 2 metres before falling to the ground. But at the same time, we expel hundreds to thousands of smaller microscopic droplets — aerosols — that can float in the air for minutes to hours like smoke or fog, and travel 6 metres or more, studies show. Aerosolised respiratory droplets are generally in the 1- to 10-micron range and viral particles “hitch a ride” on larger dust or water microdroplets to become airborne

Of course, Covid-19 can be transmitted through contact too – so we mustn’t forget social distancing, regular handwashing and sanitising of surfaces and anything else we may touch.

Evidence for air purifier filters being effective against COVID:

Most filters on the market claim it is possible to capture viruses, including “corona-like” viruses, and hence suggest that they are effective against COVID. Yet to our knowledge, there is only one actually tested against COVID – the AURABEAT AG+.

Other purifier filters capture airborne particles until they become inactive; they don’t kill the particles. And, as it’s not clear how long trapped particles stay active, it has been advised to be “cautious when replacing the filters”.

In contrast, the AURABEAT AG+ filter technology has been certified by independent tests, conducted by US virology laboratory MRI Global, using COVID-19 virus, to eliminate >99.97% of COVID-19 on the filter coating, within 30 minutes. This, to our knowledge, makes the AURABEAT AG+ air purifier currently unique.

There’s new evidence coming out regularly – check back for updates.

Read More About the Science on Air Purifiers

Air purifiers have been increasing in popularity in recent years combating dust, allergens, bacteria, viruses, volatile organic compounds (VOCs) and odour from air. The terminology is confusing, with various claims of effectiveness. The bottom line is no purifier will ever be 100 % effective, will only deal with airborne particles, its advocacy is dependent on the size of a room or space, other ventilation, human traffic etc and is an adjunct to other protective measures. Saying this, there is increasing recognition of the airborne spread of many viruses (including SARS-CoV-2 which causes COVID 19), and they do add to protection.

What should you look for?

Pre-Filter: Pre-Filters are designed to improve indoor air quality by physically removing particles of matter that can be floating around e.g hair, fibre, particles, dander, and other larger particles

HEPA filter: HEPA stands for “high-efficiency particulate arresting”. The standard HEPA filter should trap around 99.97% of particulate matter larger than 0.3 microns. In actual fact, the fibres of most HEPA filters are designed to trap particles as small as 0.01 micron in diameter — just a tiny fraction of the width of a human hair.

Carbon and Nano-Crystalline Filter: Natural non-metallic minerals are used to remove harmful gases, formaldehyde, benzene, volatile organic compounds (VOC) and odour from the air.

Sterilisation / Sanitisation: Designed to kill bacteria, viruses, mould or fungal spores that can also be floating around. It’s normal to have some micro-organisms floating around – most are harmless – but, not all of them, as we know all too well at the moment. And, if you are susceptible to allergies, or if they are in high concentrations, they can cause problems.

Ionisers: Ionisers give air particles a negative electrical charge. These negative ions are expelled into the room where they attach to positively charged dust, pollen, cigarette smoke, and pet dander to form larger particles which can be more easily trapped by your air purifier’s filters.

Plasma Sterilisation: Positive and negative ions generated by the plasma generator neutralise in the air, producing huge energy to destroy microorganisms. The negative ions contain an extra electron while the positive ions are missing an electron resulting in an unstable condition. In an effort to restabilise, these bipolar ions seek out atoms and molecules in the air to trade electrons with, effectively neutralizing particulate matter, bacteria and virus cells, odorous gases and aerosols, and VOCs.

Ultraviolet Light (UV): UV kills micro-organisms like bacteria or viruses. As microorganisms in the air pass through the filter, UV rays will kill them

Aurabeat AG+ High efficiency Silver Ion technology: This innovative technology found on the Aurabeat HEPA filter (patent-pending) has been proven in independent testing to deactivate SARS-CoV-2 on the filter within 30 minutes. The company reports that this prevents active virus from being released back into the room when moving the air purifier or changing the filter.

Clean Air Delivery Rate (CADR): The higher the CADR number, the more air it filters per minute or hour for a given particle size range. These are often defined as smaller particles (e.g. smoke 0.09-1 micron), medium particles (dust 0.5-3 microns) and larger particles (pollen 5-11 microns). If the CADR is shown as just one number, it is usually the average.

Decibels: The noise of the fan – if you are unable to hear it, it probably isn’t on! Saying that, there is usually a range, with lower fans being in the 30 decibels range, a noise considered to be very quiet.

Automatic sensors: This allows the machine to automatically adjust the fan speed depending on the degree on pollution in the air. It is usually set to identify a particle size (PM) of 2.5 microns

Additional features: Other features on a machine which we believe add to its attraction are a sleep mode (which would run the fan at the lowest setting), timer modes and filter replacement indicator lights.

Don’t forget other viruses and bacteria

But whilst Covid is taking the limelight, we shouldn’t forget what else may be in the air that we breathe.

It’s cold and flu season. Whilst they seem little to worry about in comparison, we mustn’t forget that flu can kill too – around 17,000 people per year in the UK, around 500,000 globally! And both colds and flu can lead to lost days in education and the workplace, with resultant drop in productivity.

Catching a simple cold or seasonal flu at the moment, though, is even more of an issue, as anyone with respiratory symptoms needs to isolate for fear of Covid, even if it turns out not to be the case on testing. And close contacts need to isolate too – something that would never have happened in the days of colds and flu alone. And that has huge knock-on effects as well.

Reduce allergens and pollutants

Air pollution from industry, vehicles and climate change is also important to address as it is a significant trigger for asthma. Circulating moulds and fungi, pollen, dust mites and more are also a trigger for many.

Asthma UK estimates that over 5 million people in Britain are currently living with the condition – one in 11 children and one in 12 adults. It hospitalises someone every eight minutes. And recent studies show that pollution increases the risk of serious complications from COVID too.

The verdict:

With the only filter tested on COVID, and with all the additional features found on other purifiers, we believe the AURABEAT Ag+ NSP-X1 helps to protect against the spread of COVID, flu and other pathogens, as well as helping with other allergens and pollutants. We have consulted independent experts in the field and there is no simple test that will prove it reduces infection risk. As such, it should be considered an addition to other protective measures as per government advice.

But, with increasing evidence on the aerosol transmission of COVID-19, we believe AURABEAT Ag+ has the potential to reduce viral spread in communal areas, in schools, care homes, indoor public spaces and even in the home. And give you cleaner air in many other ways, besides.

References

Int J Mol Sci. 2019 Oct; Disinfection and Sterilization Using Plasma Technology: Fundamentals and Future Perspectives for Biological Applications. Akikazu Sakudo et al.