Ionic air purifiers derive from a multitude of technologies, all of which contain one or more beneficial reactive agents that claim to clean the air that we breathe. Manufacturers willingly publish test results to demonstrate the potency of these reactive agents against harmful contaminants.

Safety First – Beneficial Reactive Agents

Unfortunately, manufacturers are not as forthcoming with information on the potential harm to human tissue of users who are exposed to the reactive agents. The in-depth article dealing with this aspect is posted at EzineArticles.com.

Safety First Redux – Unintended By-products

Manufacturers are also not forthcoming about the by-products of their technology. Unbeknownst to many users, all ionic air purifier technologies generate by-products apart from the beneficial reactive agents. They are not deliberately produced but are simply unintended products resulting from current technological constraints.

Ozone, a component pollutant of smog, is the most common of these by-products. Smog, which hangs like a foggy cloud over some cities, is typically produced by the reaction of sunlight on automotive emissions such as carbon monoxide. Ozone in smog is blamed for many ills.

Please note that this article is not a discussion about ozone generators, a class of air purifiers that deliberately produces ozone in high enough concentrations to eliminate airborne contaminants. For instance, some hotels use ozone generators to get rid of tobacco smoke from rooms when they are being prepared for the next guest.

It is commonly accepted that ozone generators pose a danger to human tissue because ozone is an extremely reactive oxidizing agent. However, for some strange reason, ozone generators are still freely sold to home users as air purifiers. This controversy probably warrants another round of in-depth research in future.

All Ionic Air Purifiers Produce Some Ozone As A By-product

The focus of this article is on ionic air purifiers that do not deliberately produce ozone. There is no dispute that all ionic air purifier technologies are currently unable to completely eliminate ozone in the process of producing their beneficial reactive agents, be they negative ions, bipolar ions or plasmacluster ions and so on. It is a question of how much ozone is produced as an unintended by-product and at which point it becomes unhealthy and harmful to users of the ionic air purifier.

Most manufacturers emphasize that the ozone produced by their technology is very minimal. Often, they claim that it is way below 50 parts per billion (ppb), a measure of ozone concentration commonly cited by various parties around the world. Interestingly, there is no established legislation, only guidelines, regulating that ionic air purifiers cannot produce ozone in excess of 50 ppb. This leads us to the next question.

Is Ozone Concentration At 50 ppb Safe?

This is the million dollar question in the multimillion dollar ionic air purifier industry.

It is an even more important question for users (who typically have respiratory problems) of such purifiers since they may be harming themselves after spending good money on what they believe to be beneficial to their health. It should also be of great concern to health authorities since they are entrusted with setting safety standards that govern manufacturers and that users rely on when they use such equipment.

One would assume that the 50 ppb limit was scientifically set by some authorities, either medical or governmental. Shockingly, this does not seem to be the case. In fact, a prominent environmentalist suggested that this limit was arbitrarily set in the US FDA Amendment Act 1972 without any scientific basis. Yet, the 50 ppb figure is commonly cited, not just by manufacturers of ionic air purifiers but by health authorities all over the world as well.

To add to the controversy, the 50 ppb limit under the US FDA Act only applies to an air purifier that is sold as a medical device! Now, that’s easy to get around. It is not common to see air purifiers being advertized as medical equipment. They are typically sold as appliances for improving air quality in the home, office, factory or school. But to their credit, manufacturers of many ionic air purifiers are voluntarily using 50 ppb as a safety limit.

There is also some measure of control imposed by the US Consumer Safety Products Act which covers ionic air purifiers that are not sold as medical devices. In a 2006 study, a US Consumer Product Safety Commission found that the 50 ppb ozone limit appears to be safe. But the Commission did highlight that ozone also enters into human dwellings from outdoor air, the so-called ambient air. This may elevate the actual ozone concentration above 50 ppb when an air purifier is being operated. Strangely again, there is no legislation in the US Consumer Safety Products Act about the 50 ppb ozone limit.

California Takes The Lead – Manufacturers Of Ionic Air Purifiers Take Note!

In October 2008, the US state of California took the first steps to regulate compliance with the 50 ppb ozone limit. It is aimed primarily at ozone generators but the regulation also covers ionic air purifiers. Serious players in the industry should be factoring this very significant development in their strategies if they do not want to see their Californian market share “terminated” (pun intended).

As users of ionic air purifiers, it is also our responsibility to take the 50 ppb ozone limit even more seriously. In scrutinizing the technical specifications of any air purifier, additional factors to consider  include noting that:

(1) the 50 ppb limit should be the average concentration over a 8-hour period;

(2) the 50 ppb limit may arise from the designed emission rate or from an accumulation over time;

(3) the ionic air purifier should ideally conform with UL867, a stringent US industrial testing standard.

Scientific Assurance That 50 ppb Is Probably Safe

There is some comfort from a 2008 scientific study by Brown, Bateson & MacDonnell which concluded that exposure to 60 ppb ozone over a 6.6 hour period causes only a biologically small effect on the lungs of 24 out of 30 young healthy adults. It does seem to provide some scientific basis for the 50 ppb limit even though the study was not designed to legitimize that. Note also that the test subjects were healthy adults whereas most users of ionic air purifiers would likely be dealing with some respiratory problems.

Is 50 ppb Really Safe Now?

The current research findings above provide some reassurance.  Yet it is important to be aware that there are very prominent professors like Jeffrey A. Siegel and Richard L. Corsi from the University of Texas, USA who take the view that ozone at any level is dangerous.

They believe that ozone, even at concentrations as low as 10 ppb, triggers the formation of ultra-fine particles by interacting with chemicals (terpenes) in common household products like air fresheners, perfumes, floor cleaners and all-purpose cleaners. Ozone-induced ultra-fine particles are believed to be highly dangerous to both healthy and vulnerable human populations such as children, the aged and the chronically-ill, especially those with respiratory or cardiovascular conditions.

However the additional risks have not been quantitatively determined or adequately researched such that legislation or regulatory guidelines can be enforced.  Neither is it possible at this time to declare conclusively that the downside outweighs the benefits of ionic air purifier technologies.

As with many products in our world, there are those who make it and those who fight it. Users are usually caught in between, not knowing the final outcome of their tussle until perhaps when its too late. The next big catch phrase in the ionic air purifier industry may well be “ultra-fine particles”.

Common Sense Precautions In Using Ionic Air Purifiers

In the meantime, why not adopt some common sense precautions even as we seek to tap on the benefits from an ionic air purifier:

(1) manufacturer recommends continuous operation – don’t just blindly follow, surely our nose can tell when its irritated;

(2) manufacturer recommends certain maintenance schedules – follow religiously here, even if it means forking out service fees;

(3) protect vulnerable members of the family – no one needs to be in a room while its being air purified;

(4) avoid usage of aerosols such as insecticides, air fresheners, perfumes and deodorants when running the air purifier;

(5) minimize other sources of ozone – e.g. outdoor ambient ozone, desktop laser printer;

(6) keep updated on developments in ionic air purifier technologies;

(7) keep track of research by prominent detractors who are eminently qualified e.g Prof. Siegel and Prof. Corsi.

There is no reason to be put off by having to take precautions when using an ionic air purifier. We do that for many appliances and machinery used in everyday living.

Ionic Air Purifiers – To Use Or Not To Use?

Despite all the controversy, there is no need to abandon the search for the ideal ionic air purifier. Why throw the baby out with the water? The ideal approach lies in keeping tabs with advancements in the various technologies, in encouraging manufacturers to be more open in their communications and in enhancing user understanding.

There is also no need to flee from ionic air purifiers to embrace the much-touted HEPA air purification technology simply out of fear or as a result of erroneous conclusions from inadequate research. There is no bias here against HEPA technology or any other air purification technology. HEPA is a time-tested great technology and should be used, but only for what it is designed to do. No one has claimed that HEPA will kill microscopic contaminants.

A key motivation for this on-going, almost obsessive, research into ionic air purifier technologies is preparing for the next global flu pandemic. To date, only the Sharp (no affiliation to the author) plasmacluster ion technology claims to destroy the bird flu virus in double quick time.