Blueair Air Purifiers Review: Ionizer and Ozone a Health Danger?

Blueair air purifiers such as the Blueair Blue Pure 211 and 411 models are some of the most popular air purifiers on the market. Yet there is confusion about whether Blueair air purifiers use ionizers and produce ozone.

In some sections of their website, Blueair avoids answering the question directly, instead saying that “Blueair air purifiers use a combination of mechanical and electrostatic filtration.” They call it “HEPASilent” technology and distinguish it from ionizers by claiming that ionizers release ions into the room, whereas the Blueair doesn’t do this.

However, on Best Buy, Blueair Support has stated that their air purifiers do in fact “have small Ionizers in them which cannot be turned off.”

So, what’s the truth? Do Blueair purifiers contain ionizers? Or do they use some other type of non-ionizer technology? And do Blueair purifiers produce ozone? We’ll speak with data.

Do Blueair Blue Pure 211 and 411 Air Purifiers Use Ionizers?

In short: yes. On the published date of this article, we checked the California Air Resources Board database for certified air purifiers, and all of Blueair purifiers are listed as “electrostatic,” which includes ionizers. This is not just the Blueair Blue Pure 211 and 411 models.

In Blueair’s illustration of how the HEPASilent Technology works, they explain how particles receive an electrostatic charge (or get ionized) in an “ion chamber.” We took apart a Blueair 203 purifier to take a look at this ion chamber.

Blueair air purifiers use ionizers

It turns out, it’s just an ionizer called an ion generator.

Blueair air purifiers use ionizers

Here’s a look at the brush side of the ionizer, which emits the ions into the air.

Blueair air purifiers use ionizers

How can we be sure it’s an ionizer and not something else? One piece of evidence is all of the dirty particles we found sticking to Blueair air purifier shells.

Blueair purifiers use dangerous ionizers

What’s happening here is that the particles in the air are getting ionized and then sticking to the nearest surface. In this case, the particles are sticking to the surface of the air purifier and not the filter itself.

Blueair purifiers use dangerous ionizers

This is exactly what happens with regular ionizers, which emit particles into the room. The only difference is that, with regular ionizers, the particles stick to surfaces in the room:

Learn more: What are ionizers and how do they work »

Why Nearly All Purifier Companies Add Ionizers

It’s quite simple. Adding an ionizer is an extremely cheap way for an air purifier company to increase its purifier’s CADR (a measure of performance). Additionally, consumers are typically unaware of the negative effects of ionizers (or the fact they are in the purifiers at all).

Studies Show the Danger of Ionizers

Ionizers create air pollution. They are not good purifiers because (1) most ionizers are too weak to have an effect, (2) they produce harmful ozone, PM2.5, Harmful VOC Gases, and Formaldehyde (3) they shoot out negative ions which cause particles to stick to surfaces in your home, rather than actually removing them.

Do Blueair Air Purifiers Produce Ozone?

We tested for ozone next to the ionizer in a Blueair purifier. The tests found this Blueair air purifier produced 181 parts per billion (.182 PPM) of ozone, which far exceeds the California Air Resource Board limit of 50 parts per billion. However, note that our test is right next to the ionizer, whereas the certification uses tests away from the purifier, which are lower of course.

Blueair air purifiers emit ozone

Other tests show ions escaping the Blueair 203 into the outside air, which can react to create chemical gases such as formaldehyde.

Are Blueair Air Purifiers Harmful?

Ozone produced by Blueair purifiers is not the only concern. The Illinois Institute of Technology tests also found that the ionizer function increased the ambient negative ion concentrations from an average of fewer than 2000 ions/cm3 to over 20,000 ions/cm3. It is possible these ions interact with other things in the air to produce dangerous VOCs – something the HEPA filter doesn’t capture.

Read More: 4 Steps to Choosing the Best Air Purifier

Bottom Line: A Review of Blueair Air Purifiers


Blueair purifiers do use ionizers, including the popular Blueair Blue Pure 211 and 411 models. There is evidence that these ionizers increase effectiveness of the filters, but they also produce ozone and might create other harmful byproducts.

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