Do ionizers kill viruses?

This article discusses the efficacy of air ionising devices against viruses. We also discuss the other advantages as well as the disadvantages of using an air ioniser, and lastly, whether it is worth investing in an air ioniser.

Do ionizers kill viruses

No, air ionisers do not kill viruses in any way. However, air ionisers destabilise viruses that are airborne, or spread through droplets.

These viruses also include the flu viruses, as well as the SARS-CoV-2, the virus responsible for causing the novel coronavirus.

However, ionisers can help in removing viral particles from the indoor air by entrapping them and causing them to sediment on surfaces.

What are air ionisers and how do they work

There are mainly two types of air purifiers – ones use filters and pull in the indoor air, which causes the pollutants to get filtered out, thereby cleaning the air.

The other type of air purifiers, which is the main subject of this article, are the air ionisers. These devices generate ions, which do so by using a mechanism called corona charging.

These ions interact with pollutants that have a charge. When these combine, the pollutant species become heavy and get removed from the air by settling on the ground.

In the case of viruses, such as airborne viruses and viruses that transmit via droplets, the viruses require a medium for transport.

In the case of the former, transmission efficiency increases in the presence of pollutant particles, as they provide a surface for the viruses to latch onto and float in the air.

As in the case of the latter, which also includes flu and coronavirus, the transmission requires aerosols or droplets, which can end up being inhaled or come directly into contact with the eyes, nose, or mouth.

However, either the virus or the transmitting medium can have a charged surface. This is where air ionisers come into the picture.

The ions generated by air ionisers interact with the charge present on the medium’s surface, which is suspended in the air.

As the ions start accumulating, the weight of the particle starts to increase.

At a certain point, the medium containing the viral particles becomes too heavy to stay suspended in the air. Therefore, these particles, along with the virus, get removed from the ambient air, thus reducing the risk of infection of the occupants.

Other advantages of using an air ioniser

Anionic air purifiers also have certain advantages, which include:

  • Helps in relieving symptoms of allergies
  • Gets rid of odors
  • Can efficiently remove ultrafine particulate matter (UF).

We shall discuss them in brief.

Helps in relieving symptoms of allergies

Studies have shown that air ionisers are effective in getting rid of allergens, which include pollen, spores from mold, animal dander, dust, and so on.

These allergens usually have a charged surface, due to which they can attract the ions generated by the air ionising necklace.

This, in turn, causes the particles to get too heavy, due to which they cannot stay suspended in the air for a while, which in turn causes them to sediment.

This helps to reduce the number of allergens which can get inhaled, due to which an allergic response can get triggered in people.

Gets rid of odors

Air ionisers interact with odor causing molecules as well. Odor is caused when a particular pollutant interacts with the sensory neurons present in the nose lining.

This is done by different bonding sites. Hence, different substances have a distinct odor. However, these ions interact and bind to the bonding sites of the odor causing pollutants.

This, in turn, renders the pollutants ineffective, due to which the odor cannot be picked up by the nose. Therefore, air ionising necklaces are useful especially when one is passing through polluted areas such as open dumps or sewages, traffic, and so on.

Can efficiently remove ultrafine particulate matter (UF)

Ultrafine particles (UF) are a class of particulate matter (PM), which are less than 1 micron in terms of aerodynamic diameter. These are generated from various sources, such as traffic, industrial emissions, combustion, cigarette smoking, etc.

There are many studies that have established a correlation between exposure to UF and reported cases of illnesses related to pulmonary or cardiovascular systems, cancers, and in some cases, premature deaths.

This is primarily because these particles can easily penetrate all the way through the respiratory passage, and end up in the deep recesses of the alveoli, the site where air exchange between the lungs and blood takes place.

However, ions generated by the air purifier can efficiently pick out these UF particles and in a way similar to that for allergens, remove them from the ambient air.

Side effects of ionic air purifiers

Ionic air purifiers, although used widely nowadays, as personal air purifying necklaces, indoor air purifiers, and other similar appliances, do have certain side effects attached with them during their working. This includes:

  • Low efficiency
  • Production of ozone
  • Can attract pollutants on the body
  • Can generate more dust

Let us discuss these in more detail.

Low efficiency

Conventional air purifiers are known for their high efficiency rate of removing pollutants from the ambient air. However, the same cannot be said for an air ioniser purifier.

In an experiment carried out by Shi et al, air purifier necklaces that use anions as their purifying mechanism were used from different brands in a small stainless steel chamber. 

It was found that the particles had a highly variable particle removal rate, but did not perform efficiently. Some of the devices had discharged at a relatively shorter amount of time.

Production of ozone

Anionic air purifiers work by generating ions at the rate of thousands per minute. They do so by using a mechanism called corona charging, in which oxygen molecules can also get broken down, which in turn react with each other to form ozone.

Ozone is a highly reactive gaseous molecule which is naturally present in the upper layers of the atmosphere, where it absorbs the sun’s damaging ultraviolet radiation.

When present in the lower levels of the atmosphere, however, it acts as a pollutant, and can have serious adverse effects on human health, which also includes afflictions related to the cardiovascular and respiratory systems.

Ozone acts as an irritant, due to its pungent odor. It can cause wheezing, irritation in the nose and throat, runny nose, watery eyes, difficulty in breathing, and so on.

Additionally, ozone can also worsen the condition of people who are suffering from diseases such as asthma, emphysema, and bronchitis.

Can attract pollutants on the body

Anionic air purifiers work by releasing ions in the vicinity of the user. These ions can also get stuck to the skin, particularly in the face and neck region.

In turn, these ions can attract pollutants towards the user itself, and can cause deposition of pollutants on the skin of the user. This can cause adverse effects on the skin, depending on the nature of the pollutant species.

Certain toxic species, which are heavy metal pollutants like lead, can be attracted towards the skin, and can have serious implications on the health of the user.

Additionally, in case if the air contains Volatile Organic Compounds, or simply VOCs, the ozone generated from the device as a byproduct can react with the VOCs in order to give rise to secondary organic aerosols (SOAs).

These SOAs do not have any implications on human health. However, they reduce the efficiency of the anionic air purifiers, as they reduce the  particle removal performance.

Can generate more house dust

Unlike the air purifiers with HEPA filters, air ionisers do not help with dust present in the house. On the contrary, they would contribute even more to the dust generated indoors.

Air ionisers interact with the charged pollutant particles by sticking to them, causing them to become too heavy to stay suspended in the ambient air.

This would in turn cause deposition of dust on surfaces such as carpets, tables, etc., which in turn would exacerbate the effect of dust already present indoors.

Moreover, this can also provide the virus particles present in the air an additional surface to latch on to and thereby propagate to other places in the house, thereby putting the occupants at risk.

However, it would be ideal to pair it with an air purifier containing a HEPA filter, as it would increase the efficiency with which the indoor air gets cleaned.

Conclusion – Should you invest in an air ioniser?

No, you should not invest in an air ioniser. Air ionisers alone do not kill viruses, but can cause the virus-carrying particles to sediment onto surfaces, which may reduce the risk of infection.

However, since an issue with air ionisers is the generation of ozone, it can be harmful for the health for using such ionisers. But if you have an air purifier with HEPA filters, which has an ioniser as an additional component, it would be ideal to use it.


Can air purifiers with ionisers also help to keep covid-19 in check?

Yes, air filters can help to keep in check the spread of covid-19 in an indoor environment. However, the filters themselves cannot kill the virus.

However, these devices can only stop the viruses that are spreading through long-range transmission via aerosols such as droplets, particles, etc.

What is the ideal place to install the air purifier?

The best suited place for installing your air purifier is on the wall, at a height of about three to five feet above the ground, in a room which receives the highest airflow rate with respect to the other rooms.

Furthermore, care should be taken when placing the air purifier. It is necessary to ensure that there is no obstacle in its path, and it is away from other electronic devices at least by a distance of 5 feet.

However, due to certain circumstances, it would not be ideal to mount the air purifier unit on the wall. However, there are many models available in the market which are designed based on the user’s preference to place the air purifier.

Lastly, it is important to buy an air purifier which has a coverage area suited to the requirements of the user.

Other FAQs about Air Quality that you may be interested in.

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My basement is dry but still smells musty?

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