What is a personal air purifier and how do they work?

Personal air purifiers have gained popularity in recent years, with more of us living in urban areas where pollution levels are higher. If you’re concerned about the quality of the air you’re breathing, you can purchase small wearable air purifiers, as well as miniature versions of full-sized air purifiers for desks or small spaces. 

But how effective are these personal air purifiers? And is it worth buying one for your desk space at work, or a wearable one to clean the air you breathe on the go?

One of the benefits of a full-sized air purifier is that they have the capacity to clean the air in much larger spaces, making them a better choice for a living room or larger spaces with higher air flow. Our guide to the best air purifiers is a great place to start. They come with a recommendation for the size of room they can support, so you can choose the air purifier best suited to your needs.

What is a personal air purifier?

A 2015 study reported that our homes and other indoor spaces are full of pollutants and allergens that can trigger respiratory symptoms, especially in those with underlying conditions such as asthma or cystic fibrosis. Air purifiers are designed to neutralize these pollutants before we breathe them in, so a smaller, portable air purifier that functions to clean the air around you might seem like a good idea to keep you safe from air pollutants outside your home.

Personal air purifiers are devices designed to clean the air around a person of pollutants and irritants. They come in the form of desktop versions, that clean the air around where you sit, or wearable necklaces that claim to clean the air around your face before you breathe it in.

Author and cleaning expert Lyndsey Crombie also says that air purifiers are great to use in your home to keep the air clean. “Indoor clean air keeps allergens at bay, like dust and pollen, and maintains a healthy environment,” she says. 

How do personal air purifiers work?

Many personal air purifiers, particularly the wearable kind, work by ionization, which has been shown to produce ozone. This is an irritant for many people with asthma and other respiratory conditions. Ionizing air purifiers function by releasing a static charge into the air around them, which causes pollutants to stick to whatever is nearest them – imagine a statically-charged balloon. Therefore, these personal air purifiers aren’t actually cleaning the air, only moving particles away from themselves. 

One 2015 study also indicated that the amount of ozone produced near the head versus the amount of irritants removed from the air breathed in made wearable air purifiers mostly ineffective in cleaning a persons’ personal space.

• Related: How do air purifiers work?

Other personal air purifiers function much as the full sized ones, using a small HEPA filter to clean the air around you. These are lightweight and easy to carry, so they are ideal to place on a desk or beside your bed while you sleep, effectively blanketing you with clean air. Air purifiers with HEPA filters function by sucking the air through filters made from paper or fiberglass, which then traps 99.97% of particles down to 0.03 microns in size and cycles clean air back into the room. 

Do personal air purifiers actually work?

As mentioned previously, it is worth avoiding personal air purifiers that produce ozone, as this is a respiratory irritant. With this in mind, portable air purifiers with HEPA filters might be the best option if you want to invest in a personal air purification system. While they may not be able to handle the particle-load of a large room, they can effectively clean the air around you and reduce your exposure to indoor air pollutants like dust, mold spores and allergens such as pollen.

• Related: Do air purifiers help with mold?

Due to their size, the radius portable HEPA filters function in is smaller than that of a full-sized air purifier, but one 2021 study showed that they can be effective in eliminating airborne particles. Alongside preventative measures such as proper ventilation and disinfecting surfaces, the researchers found that a personal air purifier may be a good investment to help protect yourself from contracting a virus. It is important to note that use of an air purifier will not replace measures such as wearing a mask, washing hands and surfaces or social distancing, but may make these measures more effective.

Experts agree that air purifiers can have an important role in keeping indoor spaces clean and free of pollutants. US Environmental Protection Agency (EPA) spokesperson Nick Conger says: “There are three simple strategies EPA advises for improving indoor air quality. Source control, improved ventilation and air cleaners.”