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User safety tops all criteria in the selection of an ionic air purifier for use in the home, office, factory or school.

Existing ionic air purifier technology, regardless of whether they originate in North America, Europe, Japan or China produce a primary beneficial reactive agent. These reactive agents may be negative ions, bipolar ions, plasmacluster ions and so on. They are produced with the objective of eliminating contaminants in the air we breathe. There is much research on the efficacy of these reactive agents in eliminating these airborne contaminants. What we do not know is whether these same potent reactive agents also cause harm to fragile human tissues such as those that line our breathing passages from the trachea to the lungs.

There is also an information vacuum about whether there are other by-products and if these are harmful to human tissues as well. However, in the industry, it is well established that current ionic air purifier technology inadvertently results in the production of by-products that may, in sufficient concentrations, prove harmful to human tissue. One of the main by-products is the infamous ozone, which in high concentrations has been tested to be harmful to human tissues.

In the light of the above, the issue of safety for the user of an ionic air purifier has to be addressed from these two perspectives:

(1) Potential harm from the beneficial reactive agents, and

(2) Potential harm from the unintended by-products.

Though not exhaustive, our intensive research on these two perspectives have been condensed into two detailed write-ups that have been featured on Ezinearticles.com.

Don’t miss these 2 in-depth Ezine articles. To read, click on the Ezine Author Badge on The Ionic Air Purifier Blog.

Ezinearticles.com, within their terms and conditions, allows publishers to freely reproduce these two articles. So help yourself, publish the two articles on your websites as a complete set, via these links:

(1) Beneficial reactive agents

(2) Unintended by-products

In addition, keep updated with our progress as we research other aspects of the very broad and exciting field of ionic air purifier technologies.

Introduction

Ionic air purifiers hold the promise of clean air, purified of all known harmful contaminants that threaten our health. Air is made impure by substances unseen by our naked eye. The weapons against such are very likely to be invisible to our eyes as well. Intuitively, the logic appeals to me. But these days, finding a simple and quick solution is rare. Googling the subject unearths a ton of controversy. Even though I am tempted to quickly get an ionic air purifier to clean the air I breathe, it is clear that more time and effort is needed. The search for an ionic air purifier must focus on its safety aspects as much, if not more, than its effectiveness against contaminants.

The recent China melamine saga that killed infants also serves as a reminder to us that in buying into any technology or any product, all claims by manufacturers and distributors must be examined to the fullest extent that our resources permit. Where the reactive agent is invisible, it becomes even more critical to focus on it. My investigation of ionic air purifier technologies falls within this realm, as the reactive agents are ions that are invisible to our eyes.

In this article, I am laying out the roadmap as I look into the existing ionic air purifier technologies in the global marketplace. My back-to-basics approach is an attempt, as a layperson, to understand the science behind the technology. A dominant current trend appears to be the creation of an invisible but potent defence shield against airborne molecular contaminants. The prime threat being closely monitored by scientists all over the world is the avian flu virus.

Types of Ionic Air Purifier Technologies

Broadly speaking, air purification technologies can be deployed in either passive or active modes. Passive mode technologies incorporate means by which impure air is sucked into the air purifier for reactive agents to work on before being re-introduced into the environment as cleaned air. Active mode depicts the proactive process of bringing the purifying reactive agents into the surrounding impure air. Interestingly, marketeers betray their lack of confidence in their own ionic air purifier technologies by combining both passive and active modes.

In the global market today, ionic air purifier technologies include the following categories:

(A) Ion generator – positive and negative ions
(B) Ion generator – negative ions only
(C) Photocatalytic Oxidation (POC)
(D) Electrostatic filter
(E) Combos

Ion Generator – Positive and Negative Ions

This combination of positive and negative ions appears to show the most promise for the future of ionic air purifier technology. They have been named as plasmacluster ions by Sharp Corporation, the Japanese corporate powerhouse that invented them.

Plasmaclusters of positive and negative ions encircle and latch onto harmful bacteria and viruses in a deadly grip. When this happens, hydroxyl is produced. Commonly known as nature’s detergent, hydroxyl is a powerful reactive species that destroys airborne particulates by removing hydrogen molecules from their organic structures. Harmless by-products, mainly water, are generated by this chemical reaction.

A differential ion generator is used in this technology, comprising a positive and a negative ion generator which can be powered in alternate cycles to control the type of ions generated.

Advocates of the positive and negative ions combination claim that a balance of both these ion types is to be found in places like waterfalls and pristine forests, i.e. this is the actual state in nature. Diametrically, believers of the negative ions technology take the view that negative ions dominate the space in natural habitats and that positive ions are actually harmful. Thus far, I have not found any independent scientific studies to support the opposing claims of the two technologies.

Ion Generator – Negative Ions

The traditional ionic air purifier produces only negative ions. This technology appears to have the main market share currently but is facing a serious challenge from Sharp’s plasmacluster positive and negative ions technology.

It is claimed that nearly all harmful airborne particulates like dust, smoke and bacteria etc have a positive charge. Negative ions from the air purifier attach themselves to these particulates until they get weighed down and fall to the ground. Vacuuming removes these neutralised impurities and therefore protects us from them. Critics of negative ion technology charge that the weighed down particulates are not destroyed and the mere act of walking around the room kicks them back into the air that we breathe.

In addition, there appears to be several methods of producing the negative ions. This is important because different methods produce different by-products, some of which may be harmful. These methods include:

(1) Water method – this employs what is known as the waterfall or Lenard Effect. Water droplets are splashed onto a metal plate where a small electric charge is applied. This splits the water droplets, a process in which large numbers of negative ions are produced. Proponents of the water method believe it to be free of harmful by-products.

(2) Electron radiation method – this is based on a single negative discharge electrode needle. Millions of negatively-charged electrons are produced when a high voltage pulse is applied to the electrode. An advantage of this method is that no ozone is produced. This is believed to be due to the application of a “smaller” energy pulse.

(3) Corona discharge method – this is based on a dual electrode model, a sharp metal electrode and a flat electrode. Between the two electrodes, a high voltage is applied. This causes the movement of electrons between the electrodes thereby ionising the air in between them. This method has been criticised for the production of harmful by-products like ozone and nitride oxide.

Photocatalytic Oxidation (POC)

This technology is commonly applied in a passive mode. It is also based on the powerful reactive agent hydroxyl which purifies impure air that is pulled through the air purifier.

Germicidal ultraviolet (UV) light is commonly shone on a catalyst (usually titanium oxide) to produce hydroxyl, oxygen and peroxide, all of which are potent oxidising agents that are very effective at destroying the organic structure of micro-organisms and gaseous volatile organic compounds.

The key pillar of POC technology is its comprehensive coverage. Proponents of this technology claim that POC inactivates ALL categories of indoor pollution, including:

(1) airborne particulates i.e. dust, pet dander, plant pollen, sea salts, tobacco smoke, industrial and car pollution, etc

(2) bioaerosols i.e. infectious biological compounds (e.g. viruses and pathogenic bacteria) or non-infectious and non-contagious (e.g. non-pathogenic bacteria, molds, cell debris)

(3) volatile organic compounds (VOCs) i.e. gaseous chemicals or odours – benzene, styrene, toluene, chloroform, hexane, ethanol, formaldehyde, ethylene, etc, all common emissions from everyday products of our modern home.

POC technology has been criticised for relying on hydroxyl which are believed to attack with equal tenacity the organic structures that make up molecular contaminants and our lung tissue, nose membranes and eye cornea.

Electrostatic Filter

This technology appears to have originated in heavy industries which produced abundant pollutants. In the most common electrostatic filter arrangement, there is a porous dielectric material positioned between two electrodes. A dielectric material does not conduct electricity while metallic electrodes are good conductors that transmit or receive electricity.

Contaminated air is drawn into the electrostatic puriifer and made to pass over the dielectric material which acts like a sieve. The electrostatic field between the electrodes causes airborne particulates i.e.dust, smoke contaminants, to stick to the surface of the dielectric. From the other end of the purifier, purified air emerges.

Frequently, an ion source is planted just before the electrostatic filter to electrically charge the airborne particulates. These impurities, so charged, stick more effectively to the dielectric material.

Critics of this technology point to the production of harmful ozone in the ionisation process.

Combo Ionic Air Purifiers

To cater to the various adherents and critics of the diverse technologies, combos incorporate all or some of the above types of technologies. Combos may include:

(1) adsorptive materials such as activated carbon or oxygenated charcoal (known for its extremely porous large surface area) are added to POC technology to enhance the removal of VOCs;

(2) oxidizing catalysts like titanium oxide are coated on various components of all types of air purifiers to enhance VOC elimination;

(3) reducing catalysts such as manganese dioxide are coated near the exit outlets of many air purifiers to reduce reactive species like ozone and nitric oxide which may be harmful;

(4) generating ions by differing methods such as using microwave, UV light, radio frequency waves, and direct current;

(5) tweaking the specifications of any ionic air purifier technology so as to attain the well-known HEPA status without actually using HEPA filters.

Obviously, the process of selecting the most efficient and effective ionic air purifier involves analysing a deluge of information. The safety issues of each technology will need much more investigation. I will also be studying in greater depth the claims of each technology. So before you put your money down for any air purifier in your homes, offices, schools, etc, check back here for updates as I continue my quest for the ideal ionic air purifier.

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