Informational Guide

Are All Air Purifiers Safe?

Our guide helps you understand the differences in types of air purifiers and why they should be considered dangerous, safe or something in between.

by Josh M

Air purifiers are a popular solution for improving your indoor air supply, but are they causing more damage than good?

This guide will help you understand the different kinds of air purifiers and why they should be considered dangerous or safe.

At first glance, it may seem obvious – of course, purifiers must be good for our health! What could be more healthy than clean air?

To understand why they may not be as safe as they appear, let’s look at the different kinds of air purifiers out there. While many dehumidifiers may come with filters to combat some air contaminants, simple air purifiers will not cool or affect the humidity in your home.

Mechanical Filtration

Air purifiers that use mechanical filtration generally use fans to pull air into the device. The air is then passed through a series of filters that remove harmful particles, allowing cleaner air to pass back out into the room. This method is the safest as it produces no harmful by-products.

HEPA Filters

HEPA stands for High-Efficiency Particulate Air filters, and this is a very apt description. The filters are made of densely packed filters woven into a mesh, which is folded to increase its surface area. These filters are one of the best forms of air purification, and they catch 99.97% of particulate matter.

The filters will need to be replaced every two or three years, and they won’t be effective for dealing with odors, chemicals, or gaseous pollutants. Fortunately, many devices using HEPA filters also include other filter sections designed to handle these kinds of contaminants.

Activated Carbon Filters

Carbon is the building block of life on Earth. Activated carbon is capable of absorbing a lot of pollution. In filters, activated carbon can grab hold of pollutants like chemicals, odors, smoke, and other gases. Once absorbed by the carbon, these pollutants can’t be released.

These filters won’t have much of an impact on particulate matter and so are most useful when combined with HEPA filters.

Electronic Air Purifier
Electrostatic Air Precipitators

Like HEPA filters, these air purifiers trap unwanted contaminants inside. However, instead of mesh filters, they use an electric charge to trap the particles by drawing them to oppositely charged plates, removing them from the air stream.

The filters for these purifiers will need to be changed about every three months. It is difficult to establish how effective these types of purifiers actually are.

Air Ionizers

Instead of drawing air into themselves and charging it, these air purifiers send out charged particles into the room. These particles then bond with contaminants and pull them down to the floor or attach them to the walls.

However, when the charge is lost, the particles will simply rejoin the air again. Ionizers don’t remove any unwanted particles; they simply move them to another surface. Additionally, despite any claims by manufacturers, all ionizers will produce a small amount of ozone as a by-product.

UV C Air Purifiers

Hospitals use ultraviolet light to purify equipment, and home air purifiers with UV technology promise the same effect – to kill bacteria and pathogens. Most air purifiers use UV c light, and this alone is safe for home use, but it may not be terribly effective, as pathogens need prolonged exposure to UV light in order to be killed or neutralized.

Air purifiers move air rapidly, not giving the UV light enough time to be effective. Some UV purifiers also produce ozone, which is best avoided when choosing an air purifier.

Photocatalytic Air Purifiers

Photocatalytic oxidation air purifiers, or PCO cleaners, also use UV light, along with a catalyst that reacts with the UV light to remove gaseous pollutants from the air. This type of purification on its own will not deal with particulate pollutants.

Ozone Generators

Ozone generators, as their name suggests, release a great deal of ozone molecules into your airflow. The device creates ozone molecules by splitting oxygen molecules – which requires a lot of voltage!

These types of purifiers don’t trap pollutants but instead oxidize biological contaminants, gaseous pollutants, odors, allergens, and particulates. To be useful at all, you need to use a lot of ozone. And while this may handle the pollutants, inhaling ozone isn’t safe for humans or animals.

2 Types Of Indoor Pollutants Commonly Found In Homes

There is a near endless list of places where pollutants could be found in your home. Every room and occupant comes with its own by-products and potential air pollution, with the most common being dust created from our dead skin cells. Indoor pollutants can be broken down into two categories – particulates and gaseous.

  1. .Particulate matter
    These contaminants are things like dust and dust mites, hair and pet dander, smoke particles, molds, bacteria, viruses, pollen, and other microorganisms. They can cause allergic reactions and breathing problems for some people.
  2. .Gaseous pollutants
    This kind of pollution is made of gases and odors. It may come from the ingredients in fuels, from medicine, cosmetics, perfume, or aerosols. Plastics and other materials may create gaseous pollutants, as do pet odors and smoke.
Indoor Pollutants in Homes

Are Air Purifiers Safe & Are They Good for Your Health?

Because of some of the methods used by air purifying devices, consumers have often wondered if the devices themselves might be posing more of a health risk than the problems they’re claiming to solve. Not all air purifiers are dangerous, but there is reason to be wary of some.

1. No Ozone, Please

As mentioned above, ozone generators purify the air by oxidizing contaminants. This seems effective at purifying your air, but the side effects of being exposed to large amounts of ozone, which is required for this method to be successful, are potentially worse than dirty air.

The EPA lists ozone as a lung irritant, and too much exposure can be very harmful for someone with respiratory conditions such as asthma. Even more alarmingly, the symptoms inhaling ozone can induce may stop over time, making you less aware of the damage the air purifier is doing to your body.

As cleaner air can be healthier for people with lung conditions and allergies, the worst possible device would be one that could cause further harm. Additionally, ozone generators may not be effective at killing off mold, mildew, and bacteria. Your home may smell cleaner after using one only because the ozone smell covers the other odors and pollutants.

The effects of ozone inhalation can include:

  • Coughing
  • Shortness of breath
  • Throat irritation
  • Difficulty breathing
  • Less resistance to respiratory infections
2. Same Pollutants, Different Place

Ionizers are not the same as ozone generators, but they too release particles into your home to tackle pollutants. However, ionizers don’t collect, neutralize, or get rid of the particles they’re pulling down. Eventually, the charge wears off, and the pollutants enter the air supply again.

Unless you’re cleaning all your surfaces constantly, ionizers aren’t going to be entirely useful. To be able to keep stopping these particles from floating around with the air, you need a very powerful ionizer, and the stronger the ionizer, the more ozone they produce as a by-product.

Even devices claiming to be low or zero ozone producers will be creating some, and are best avoided.

3. Does the filter catch everything?

Mechanical filtration releases no chemicals and emits no by-products, so it is by far the most attractive prospect for air filtration. However, HEPA filters will only deal with particulate contaminants and won’t make a difference to odors or gaseous pollutants.

This can be easily remedied by purchasing a purifier that combines HEPA filters with activated carbon filters, which are great with gaseous pollutants and odors such as smoke. HEPA filters were used in hospitals during the 2003 SARS outbreak, as recommended by the CDC, but there is not enough evidence to prove how well they deal with COVID-19.

What Types of Air Purifiers Are Safe?

The most reliable kind of air purifiers are undoubtedly those that use mechanical filtration. Devices with a variety of different filters can ensure as many contaminants as possible, both particulate and gaseous, are dealt with.

To avoid potential health hazards, ensure the air purifier of your choice follows these specifications:

  • Does not generate ozone (This includes ozone generators, ionizers, and some UV air purifiers)
  • Is not an ionization or electrostatic precipitator
  • Provides for proper airflow to reach all the air in a room – if the airflow cannot move freely in a room, the purifier will not be as effective as it needs to be
  • Mechanically filters the air
  • Has an air filtering capacity of 1,100 to 2,200 CFM – purifiers with a lower rating than this will not offer a good enough Clean Air Delivery Rate (CADR). At 1,100 to 2,200 CFM, purifiers can filter a room 20 to 40 times an hour.

Air Purifying Plants Safe for Pets

The health and safety of pets is another big consideration when looking at air purification methods. Ozone is equally as harmful to animals as humans, so it should certainly be avoided by pet owners.

If you’d prefer to purify the air in your house with a more natural method, there are several kinds of plants that will provide natural air filtration without the concern of by-products or chewed cables. Plants can filter chemical contaminants from our indoor air while also looking very pretty.

Before introducing any new plants, always ensure they are pet safe and non-toxic. Pet-safe plants that are great at natural air filtration include bamboo palms, spider plants, Gerber daisies, prayer palms, and Boston ferns.

Avoid rubber plants, snake plants, jade, aloe, philodendrons, and a whole lot of others.

Air Purifying Plants Safe for Dogs and Cats

People Also Ask (FAQ)

Do all air purifiers give off radiation?

No – mechanical filtration air purifiers give off no radiation or other harmful by-products.

Do you need an air purifier in every room?

This may depend on the size of your home and the pollutants you most want to deal with. Consider if you need a permanent filtration system or if a portable air purifier that can be moved from room to room would best suit your needs.

Do air purifiers get rid of smell?

Air purifiers that use technology to tackle gaseous pollutants will deal with unpleasant odors. Activated carbon filters are great at absorbing odors and other gaseous pollutants.

Does an air purifier use a lot of electricity?

This will depend on the type of purifier, although many are pretty energy efficient. Mechanical purifiers will use a lot less electricity than electronic air purifiers or ozone generators.

Does boiling vinegar clean the air?

While boiling vinegar may deal with some odors, it will not kill viruses, and it is not safe to boil vinegar.


Air purifiers can make a world of difference in keeping your home clean and safe. It’s important to make sure the device you choose is the best and healthiest option for both you and your family.

Last Updated on July 16, 2021

Josh M

My name is Josh and I am obsessed with the HVAC industry. I created this website to help HVAC techs of all levels get the best out of their heating & cooling systems. I have spent thousands of hours studying air conditioners, heaters and home air products so you can learn & buy with confidence. Learn more about the team here.