What Is An Ionizer? How Does It Work?

Many people are confused about the negative ion generator and are not surprisingly so. Frequently asked questions include how does an ionizer work? Is it better than an air purifier or ozone generator? How safe and reliable is the technology? Does it have any side effects blah blah blah...... Fret not as all of these popular questions will be answered one by one. As a bonus point, we will give a definite answer on the best type of air purifier for home.


How Does An Ionizer Work?

Ionization is when an atom/ molecule gains or loses an electron. An Ionizer works by electrostatically charging negative ions internally and dispersing them into the air. The released negative ions will merge with positive ions particles in a room like a magnet. This includes dust mites, mold/ mildew, pollen, pet dander, bacteria, and viruses. The bonded ions will fall due to the increased weight leaving the air free from contaminants. Owners will have to vacuum/ clean up the particulates on the ground, wall, or sofa before it stirs back up again.

How do I know if ionizers really work? Most of your allergic reactions will lessen or fade away in a few days. Also, there is a hint of burn ionized air smell that one will get used to it.

Debunking Air ionizer Dangers

Let’s start with a few clear statements. Ionic air purifier is 100% safe with no side effects as it’s proven time and time again. Ionizer would not make you sick as it disperses only negative ions. The reason some reports stated otherwise is those “fake” ionizers. The so-called Ozonizer is masked as an ionizer or integrated with the ionization feature. Nothing’s good when you mix with the bad crowd. The problem with Ozonizer is that they rely on ozone to perform its purification. Inhaling even a small amount of ozone is bad for our health, particularly the lungs.

Blueair ionizer animation
Example of Blueair HEPAsilent Technology

Air Ionizer Benefits

Probably the only site that asks you to be less positive! By now, we should all agree that breathing in more negative ions, and less positive ions are beneficial to our health and well-being. Using an air ionizer will balance things up by introducing more negative ions into the air. There are still a few more advantages an ionizer can bring to the table that no other air cleaner could.

  1. Evergreen technology that does not rely on any filter. You will save up a lot on the filter replacement cost.
  2. Pairs well with a HEPA air purifier or as an Electrostatic Recipitator.
  3. Boost body immune system on seasonal allergies like hay fever, cold, and even migraine.
  4. Protect our lungs and respiratory tract from inflammation.
  5. Helps you sleep better by relieving tension. Mood booster!
  6. A natural antidepressant for a person suffering from depression.
  7. Stay sharp. Improve mental focus and clarity through the increased flow of oxygen.
  8. Elevate person health, energy level, and well-being.
  9. Revitalize cell metabolism and speed up healing rate from injury.
  10. Normalize respiration rate that helps reduce stress and blood pressure.

According to Clean Air Optima, did you know the lack of negative ions can cause serotonin hyperfunction syndrome or irritation syndrome (SIS)? Debilitating results of surplus positive ions include dizziness, migraine, nausea, heart fluttering, hot flashes, or shivering. It can also cause mental tension, insomnia, fatigue to depression. Inhaling excessive positive ions can irritate the airways. On a bad day, it can aggravate asthma, bronchitis, hay fever, or rheumatism.

What Is An Air Ionizer?

AKA Ioniser, Ionic air purifier, Ion generator, or Negative Ion air purifier. An air ionizer is a device that cleans the air by discharging 20,000 and 200,000 ions per second to bring down airborne particulates. There are 2 common types of ionizer in the market. First, an electrostatic precipitator that comes with an extra collector plate. The "plate" collects the drop contaminants rather than leaving them falling all over the place. The purification process is eco-friendly. Thus, you can reuse the plate over and over again. The second is an air purifier with an ionizer that pulls in and captures fallen ions onto its filter. Most of the HEPA filter is not reusable, but it's proven to be much more effective in trapping the fallen. Some ionizer produces a very insignificant amount of ozone that can be safely ignored.

With no short of options in the market, here are our best ionic air purifiers pick that is effective, safe, and CARB-approved.

Ionizer VS Ozone Generator

An ionizer is not an ozone generator even though some manufacturers market them as the same. The former produces ions, while the latter produces ozone. Ionizer only causes the contaminant to fall while the ozone generator disintegrates them. While at this stage, ozone generator might seem superior, it is, in fact, very dangerous and detrimental to our health. Why? Because ozone is a highly reactive gas that can be unstable when mixing with other compounds. In-proper use of the device can lead to high exposure to ozone that will damage our lung tissue in return. An ionizer is a far safer method than combines well with an air purification system.

Air Ionizer VS Air Purifier

Both devices strive for clean air by removing airborne irritants. That's all the similarity ends as they utilize a different set of technology. Air ionizer electrostatically charges and merges ions causing them to fall to the ground (or anywhere in between). Conventional HEPA air purifier pulls in impurities and trap them in the filter. An air purifier is far more efficient than a standalone ionizer in clearing out contaminants. There are some advantages air ionizer holds that we alluded to earlier. My question is, why not both? Many excellent HEPA air purifiers with ionizer features come from Honeywell, Blueair, or Rabbit Air. You just have to find the right balance between them.

Do Ionizers Kill Mold or Get Rid of Dust?

Technically, ionizer does not "kill" any microbes or any particles. The device's negative ions emission causes ions to drop due to the increased weight. Without an air purifier or collector plate capturing the fallen particulates, the mold, dust or any irritants will still be in the room. It will spread on the wall, sofa, or floor until you vacuum it up.

Ionic Air Purifier VS UV Air Purifier
Clarifion Negative Ion Generator GL-139 Review

What Is Ionizer?

Bipolar ionization (BPI) or ionic air purifier is a popular air treatment technology integrated into many HVAC systems. Using electric current generates safe positive/ negative charged ions that attach to other pollutants in the air, including dust, hair, lint, fiber, pet dander, mold, mildew, bacteria, and viruses. The enlarged particulates will fall due to the increased weight, and the air purifier will draw the particles into its multi-stage filtration for capturing. Otherwise, the fallen particulates will adhere to a surface area like a wall, ceiling, sofa, bed, or floor. You will have to perform vacuuming and cleaning to remove the contaminants.

PureZone 3-in-1 True HEPA Air Purifier Review

What Is UV Air Purifier?

UVGI or UV air purifier is a type of air purification system that uses 254nm short-wavelength ultraviolet light to break down biological contaminants in the air, including mold, germ, bacteria, and viruses. By destroying the nucleic acids cell and altering the pathogen's DNA/ RNA, the pathogen loses the ability to reproduce and spread. Without the allergens triggering allergies, you will breathe better and enjoy a better sleep quality. Given its efficiency against pathogens, you can find UV technology in hospitals, medical facilities, laboratories, meat processing, HVAC system, and manufacturing factories.

There are 2 main varieties of UV disinfection:

  • Upper-room UVGI air disinfection - Irradiate the upper portion of the room without affecting the occupants. An excellent option for continuous disinfection.
  • Surface/ In-room air disinfection - The less common type due to its hazardous nature. Often used to disinfect unoccupied spaces, and building occupants require UV protective gear.

In short, the shorter bands, the higher the frequency of UV light and the stronger energetic UV radiation. There are 3 types of UV lights classified ranging from 10nm to 400nm:

  • UVA - Slow vibration and long-wavelength 315–400 nanometers photons. Commonly used in tanning booths or disinfection tools due to its mild nature.
  • UVB - Normal vibration with medium-wavelength 280–315 nanometers photons. Often used in plant development to alter plant hormones.
  • UVC - Fast vibration with short-wavelength 100–280 nanometers photons. The most popular UV-C lights are due to the UV radiation effectiveness in killing pathogens.

As we briefly introduce how ionic and UV air purifier works, let's now look into the differences between them and compare the specification.

Safety Concern

Ionizer or bipolar ionization may not have the long history (1970s) and in-depth research as UV, it is also a safe technology found in many air purifying devices. Unfortunately, it is plagued by many falsified claims associated with an ozone generator. To avoid purchasing a fake ionizer, AHAM and CARB recommend purchasing a multi filtration air purifier over a dedicated ionic device.

UV light has been around since 1908 and backed by many scientific studies. It is a safe technology found in the army, CDC, and health care centers as bio-defense systems to isolate the spread of disease. Furthermore, the FDA regulates companies that manufacture, repackage, All import UV medical devices in the United States. Always choose a model from a reputable manufacturer, like Honeywell, Alen, or Blueair.

However, UV can be dangerous if misused. Direct exposure can lead to sunburn, skin wrinkles, and premature aging. There is also the hazardous mercury risk from a broken UV lamp.

In short: UV air purifier is better recognized and validated.

Ozone Emission

BPI or ionic air purifiers release ozone byproducts during ionization by splitting oxygen molecules (O2) split and reform into ozone (O3). It is under EPA 0.05 ppm limitation; therefore, it will not have any adverse health effects. As the technology matures, newer Ion products are certified as ozone-free by UL 2998 standard certification (Environmental Claim Validation Procedure (ECVP) for Zero Ozone Emissions from Air Cleaners). Still, you should inspect the ozone emission data report from the manufacturer before investing in one.

UVGI or UVC air purifiers will release a low level of ozone byproducts during photolysis. The ozone emission level is insignificant to cause any harm thanks to the 254 nm short-wavelength and coated lamp. You can safely use it indoors as long as you are not directly exposed to it.

Ozone is an unstable colorless gas that can cause coughing, chest pain, sore throat, inflammation, headache, and breathing issues. Prolonged exposure can aggravate asthma, scar lung cell tissues, and damage the lining of the respiratory system. Ozone can also lead to hazardous chemical reactions with foreign substances found in paint strippers, aerosol sprays, asbestos, radon, and pesticides.

In short: Both will generate ozone byproducts no more than the 0.05 ppm limit. Still, UV technology produces far less.


UVC light is very effective at destroying biological pollutants, including mold, germ, bacteria, and viruses. It is ineffective against large particles like dust, hair, lint, pet dander, and even less effective against smoke, odor, and chemicals like VOCs.

While, BPI/ Ionizer does not actually eliminate airborne pollutants, it is a tremendous assisting tool for air filtration like HEPA and activated carbon.

In short: Different functionality, different purpose.


Both devices require minimal maintenance and care compared with a filter-based air purifier. Ionization technology is filterless, reusable, and ever-green. As a trade-off, you will have to clean up the room regularly to remove the fallen particulates. A UV air purifier does not require vacuuming or house cleaning to get rid of the pollutants. However, the UV lightbulb needs replacing every 5,000-20,000 hours, depending on the size and usage time. As such, there will be recurring maintenance costs to incur.

In short: Tied. Pick the one that is best suited to your need.

Against COVID

Ionization can help reduce COVID-19 in the air, as stated by EPA. Still, limited scientific studies and research are conducted considering BPI an emerging technology.

UVC light can effectively disinfect COVID-19 particles and viruses, according to CDC. American Journal of Infection Control (AJIC) confirms that a high load of SARS-CoV-2 was destroyed after nine minutes of UVC exposure. Nature also researched that far-UVC light kills 99.9% of Coronaviruses in 25 minutes.

In short: UV-C light is the better choice against COVID-19, but there's no harm in having both. Either way, UV and ions cannot prevent COVID-19 infection. It will only reduce the risk of catching one. Personal hygiene, face mask, practice social distancing are still the way to go.

Which Is Better: Ionizer Or UV Air Purifier?

While both have their pluses and minuses, UV is the better option when compared to ionic. UV-C air purifiers inactivate and disinfect mold, germs, bacteria, and viruses to prevent pathogens from growing. UV technology also has a long history of scientific backing and research since the 1908s. Bipolar ionization is less effective as it does not completely remove the airborne pollutants in the room. It also lacks quality research, and the technology is often subject to false claims due to its correlation with an ozone generator. Regardless of which type you choose, both can be used safely for residential and commercial purposes. An ionizer or UV air purifier will help remove biological pollutants from the air. We highly recommend purchasing a genuine, multi-stage HEPA air cleaner comprised of either/ both technologies approved by AHAM, CARB, and the FDA. You can go to our best air purifier for UV or the best ionic air purifier to get started on your buying journey.

Are Air Purifiers With Ionizers Safe?

Are Air Purifiers With Ionizers Safe

Air ionizers are safe to use and harmless to our health. It emits millions of negatively charged ions that attract and bond with other positive ions contaminants in the air, pulling it down from the increased weight. The air purifier’s filter will capture the harmful pollutants, resulting in a cleaner, safer, and healthier air environment.

Negative ions are odorless, tasteless, and invisible molecules that are naturally occurred in environments such as waterfalls, mountains, beaches, lightning storms, and sunlight. Besides improving indoor air quality, inhaling negative ions can boost your emotional well-being. Health benefits include an increase in daytime energy levels, alleviation of depression, and relief stress. You will live happier by producing biochemical reactions that increase the mood chemical serotonin levels.

Air Ionizer Dangers

Ionizers or ionic air purifiers pose no danger to our health. The biggest concern is many people cannot tell the differences between ozone generators and ionic air purifiers. The confusion is due to the unethical practice by a few bad apples. Some manufacturers labeled their “ozone generators” as “air purifiers” to fool the consumers so they could sell more units to the market. It is unethical and can cause more harm than good.

A good example would be the infamous Sharper Image Ionic Breeze case. An electrostatic precipitator air purifier releases traces of ozone byproducts, according to Consumer Reports in 2005. Sharper Image, the company for Ionic Breeze refuted the claims and brought them to court but ultimately lost. It was the final nail to the coffin as the company when bankrupt after the lawsuit.

Ozone generator has received many bad stigmas from the press and many health agencies like CARB and the FDA due to their adverse health effects. It is further solidified by the U.S. Environmental Protection Agency (EPA) that recommends users to avoid air cleaning devices that produces a high concentration of ozone. The Food and Drug Administration (FDA) regulates the ozone output for air-cleaning devices to be no more than 0.05 parts per million (ppm). This is later followed by The Clean Air Act that EPA must set national ambient air quality standards (NAAQS) for ozone. You can refer to the below air quality index (AQI) for safe ozone emission.

  • Good - 0 to 50 ppm
  • Moderate - 51 to 100 ppm
  • Unhealthy (sensitive groups) - 101 to 150 ppm
  • Unhealthy - 151 to 200 ppm
  • Very unhealthy - 201 to 300 ppm
  • Hazardous - 301 ppm and higher

Ionizer Air Purifier Side Effects

Ion air purifiers that do not comply with CARB ozone limited regulation will emit harmful byproducts like ozone. Because Ozone is a gas molecule that can be exposed through the mouth, nose, or eyes, inhaling to small trace amounts can cause side effects such as:

  • Coughing
  • Chest pain
  • Shortness of breath
  • Headache
  • Lungs/ Throat irritation
  • Lung scarring
  • Damaged and scarred lungs (Pulmonary fibrosis)
  • Worsen chronic respiratory diseases
  • Asthma attack
  • Weakened body immune system

In conclusion, go with a genuine air ionizer that diffuses very little to no ozone byproducts. Be careful when purchasing an air purifier with an ionizer from unknown or unreputable brands. Make sure to look closely at the air purifier's technical specifications and find out the ozone output. Rather than wasting time scouring the internet for the right model.

Ionic Air Purifier VS HEPA Air Purifier

While both devices can improve air quality, there are big differences between an ionic air purifier and a HEPA air purifier. An ionic air purifier generates negative charge ions that attract and pull down large airborne pollutants in the air. The technology is filter-free, silent, and cost-effective. On the other hand, a HEPA air purifier draws air into multiple filtrations that trap finer particles, smoke, and odors as small as 0.3 microns. It is 100% ozone-free as no harmful byproducts are created during the air purification. The only downside is the HEPA, and carbon filter require replacing, which will add up to the maintenance cost.

So should you get an ionic air purifier or a HEPA air purifier? Go with a HEPA air purifier that offers superior air cleaning and particles filtration over an ionic air purifier. Then again, why not both? There are plenty of HEPA air purifiers with ionizer technology in the market that works very well together.

Types Of Air Ionizer Purifiers

There are two common types of ionizer air purifiers in the market: ion generators and electrostatic precipitators. Both use the same technology with little difference between them. Here is the breakdown:

  • Electrostatic precipitators - Disperse negatively charged ions into the air via corona discharge. The dispersed ions will merge with positively charged ions and collect them onto a flat plate. Electrostatic Precipitators are primarily used in a standalone ionizer to remove and collect pollutants in the air.
  • Ion generators - Disperse ions via corona discharge or UV-light but without the use of a collecting plate. Without an air purifier, the attached dirty particles will be stuck on surface areas like the wall, ceiling, bed, cabinet, table, carpet, or floor. You will need to vacuum regularly to remove the fallen dirty particles.

The differences between Air Ionizers, Ionic Air Purifiers, And Negative Ion Generator

Ignore the different jargon and name as they are essentially the same thing. Air ionizers, ionic air purifiers, and negative ion generators use the same corona discharge technology to remove airborne impurities. You can use the names interchangeably or refer to the original name the manufacturer has chosen.

Max Fernandez

A loving father and a dedicated reviewer for airfuji.com with more than 1000 air purifiers under his belt. Max Fernandez is also one of the million patients currently suffering from asthma. Feel free to nudge him if you have any questions.
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