Air purifier effectiveness against Covid 19 : sorting out the real from the fake

There is no real-world evidence of the effectiveness of air cleaners

FALSE
Many devices have been tested in real-life conditions. A recent study in Germany showed the possibility of reducing the risk of virus transmission in classrooms with air purifiers. When it comes to TEQOYA air purifiers, these devices have been widely proven in the field. Here are some examples. With the help of the CERTAM laboratory, TEQOYA has carried out measurements in a 20m2 room in a slightly polluted environment. The purifier was placed on the bedside table and the results showed that the air in the bedroom is up to 70% healthier compared to the bedroom entrance.

Also, the offices of the Beaumanoir company in Shanghai are equipped with TEQOYA air ionizers. Beaumanoir's open spaces are spacious and have high ceilings (3.5 m). Our air ionisers have been installed in the ceiling, at a rate of one per 25 m2, and placed in the Our air ionisers have been installed in ceilings, at a rate of one per 25 m2, and placed at the level of the employees' workstations. In order to verify the effectiveness of our technology, we launched two measurement campaigns seven days apart. During each campaign, the level of indoor pollution, with and without air ionisers was measured, giving the ionisers 2 hours to purify the office air. Result: particle pollution was divided by three in these premises.

In fact, there are many field measurements of the effectiveness of purifiers in reducing pollution, whether from inert particles or micro-organisms such as viruses. It is important to note that these two types of pollutants are not so different for a purifier: a virus, even a small one, is carried by aerosols (micro-droplets suspended in the air) which behave ... like other particles!

Only HEPA filters are really effective against viruses

FALSE
No, other technologies also work. HEPA filters are now being promoted because they are the classic, known solution that does not present a risk of secondary pollutant emissions from active processes. The emission of secondary pollutants is particularly pointed out for photocatalysis, UV radiation or ozonation devices.

Air ionisers can also kill virus-carrying aerosols. TEQOYA air ionisers have been shown in the laboratory to be effective against viruses. Indeed, we have experimental results showing that our devices reduce the viral load in the air. They have been tested on a wide range of particle types and sizes, down to 7 nanometres.

An air purifier is not enough to reduce the risk of transmission to zero

TRUE
Air purifiers provide an additional layer of protection to the recommended barrier actions, such as regular hand washing, mask wearing and social distancing.

According to ANSES, the effectiveness of air purifiers has not been proven

TEQOYA has carried out extensive laboratory testing to demonstrate the safety of its air ionisers. The presence of any chemical compound with an oxidising potential was measured, 5 cm from the needles of the ioniser. The French laboratory CERTAM shows in its report TEQOYA air ionisers do not produce any oxidising gases.

Interaction with VOCs was also investigated, but no evidence of transformation of these gases into other gases was found. Ozone measurements in a sealed chamber for 12 hours showed no detectable emissions. In short, there is no lack of results In short, there is no lack of results to reassure us about the safety of TEQOYA ionisers. Finally, TEQOYA demonstrates the efficiency of purification by applying American and Chinese test standards (abatement tests in a closed chamber) because the French standard (filtration test between air inlet and outlet) is not feasible on an air ioniser.

Air purifiers are effective against aerosols and thus against the transmission of viruses

TRUE
Air cleaners can reduce the average concentration of particulate matter in the room, but also the concentration of aerosols emitted by speech and breathing. Therefore, air cleaners reduce the risk of virus transmission. However, aerosol reduction does not guarantee that the virus does not spread, and its effectiveness depends largely on implementation, as we explained in a post on this blog.

All air cleaners are safe

FALSE
In particular, attention should be paid to the production of ozone in air ionisers. Ozone is a powerful oxidant, which has a proven biocidal effect. But inhaling ozone can cause coughing, throat irritation, shortness of breath and other problems, especially with long-term exposure, even in healthy people. But inhaling ozone can cause coughing, throat irritation, shortness of breath and other problems, especially with long-term exposure, even in healthy people. Ozone can also cause lung damage, which is why local weather authorities sometimes issue ozone alerts. local weather authorities sometimes issue ozone alerts.

TEQOYA ionisers do not produce ozone, so they keep your air clean all the time. Other technologies, such as UV and photocatalysis, present risks of chemical reactions between species, which may, depending on the conditions of use and ambient VOC pollution, create other chemical species at least as toxic. depending on the conditions of use and ambient VOC (volatile organic compound) pollution, create other chemical species that are at least as toxic.