Will an Air Purifier Help with Cat Allergies?

You love your cat but hate what its dander does to you. Will an air purifier help with cat allergies?

Yes, an air purifier will help remove pet hair and dander from the air – two of the most common allergens.

The very purpose of an air purifier is to remove allergens and contaminants from your air, so it’s doing its job.

That’s great news for cat owners who are also allergic to cats – but it isn’t the whole story. Not all air purifiers are created equal.

So what more do you need to know? Glad you asked!


Is it True? Does an Air Purifier Help with Cat Allergies?

It’s true! Using an air purifier helps with cat allergies.

Not sure if that’s the truth or fiction? Good. Don’t take things at face value!

Here’s some proof. 

The United States Environmental Protection Agency has a page on indoor air quality. To be more specific, they address HEPA filters.

HEPA stands for High-Efficiency Particulate Air. HEPA filters are tested and certified to remove 99.97% of the following:

  • Bacteria
  • Dust
  • Mold
  • Pollen
  • … and any airborne particulates with a size of 0.3 microns

It’s that last line that’s really important. 0.3 microns is roughly the size of 1/3000th of a pinhead. 

Pet dander and hair—more specifically, your cat’s hair and dander—will get trapped by a HEPA filter.

Considering that 65% of US households have at least one pet, and 30% of those people are allergic to cats or dogs, that’s very good news.

But wait. I know some skeptics and people smart enough to check facts are out there.

And the fact is, pet dander can be as small as 0.1 microns—smaller than 0.3 microns. 

So how dare we claim a HEPA filter can capture pet dander, right?

Air Purifier and Cat Allergies: Understanding HEPA Filters and Particle Sizes

As is widely claimed, a HEPA filter is guaranteed to have 99.97% efficiency in removing particles that are 0.3 microns or larger. 

So what’s the deal with claiming it can capture particles as small as 0.1 microns?

In reality, HEPA filters can capture particles of all sizes — both smaller and larger than 0.3 microns.

How is this possible?

Part of the problem is that we think of filters as being like a sieve, with holes that either allow something through or block it. 

But that’s only partly true. In reality, a HEPA filter uses several different methods to capture even the smallest of particles.


Here’s a breakdown of how a HEPA filter captures particulates. And sorry, but this will get a little bit like science class.

  • Sieving. The filter acts like the sieve mentioned above, where anything larger than a specified size can’t get through.
  • Inertial Impaction. This happens when a particle has inertia which moves it in a specific direction— in this case, toward the filter and its fibers. Particles that are 0.5 to 5 microns will get trapped in the fibers.
  • Interception. These particles aimlessly float through the air until they’re intercepted by the filter. Any particles that are 0.1 to 1 micron will stick to the fibers.
  • Diffusion. The tiniest particles, measuring smaller than 0.1 microns, bounce off gas molecules — remember, the air is gas, eventually landing on and sticking to the filter’s fibers.

So pet dander, which is 0.1 microns in size, can still be filtered out of your environment.

Cat Allergies, Specifically Dander and Hair

First up, let’s talk about the causes and symptoms then we’ll get into more information on how air purifiers help with cat allergies.

A lot is said about cat hair, but is it the hair that triggers the allergy?

No. It’s what’s collected in the hair. More specifically, dander. 

And if you want to get even more specific than that, the proteins found in the dander trigger the allergy.

Dander, a dead skin cell, carries this protein, as does the cat’s saliva and urine. 

Your cat’s hair not only collects and holds onto the dander, but it can also carry a variety of other allergens, such as dust mites, mold, and even pollen.

This is why people are most allergic to furry animals. But anything with hair or feathers can trigger the same allergic reaction. 

As soon as the protein in the dander reaches your respiratory system, eyes, or skin, it can trigger an allergic reaction.

Pet dander is microscopic, so it floats through the air unnoticed. However, thanks to its jagged edges, it will stick to anything it lands on.

That could be your upholstery, your draperies, your clothes, you’re bedding, and even your body.

Air Purifiers Help with Cat Allergies, but They Could Use Some Assistance

Now that we’ve helped you to understand how your air purifier can help with cat allergies, how about taking it one step further?

You can do a few things in your home that will further improve the air quality for allergy sufferers. 

So apart from using an air purifier with a HEPA filter, take a holistic approach and consider doing the following:

  • Vaporizers and humidifiers aren’t necessarily your friend. Allergy sufferers should keep indoor humidity levels below 50%.
  • Air purifiers aren’t the only appliances that come with a HEPA filter. Consider purchasing a vacuum cleaner with a HEPA filter to help further reduce dust, pet dander, pet hair, and other allergens.
  • Don’t allow anyone in the home to smoke.
  • Pollen sticks to your clothes, so during allergy season, be careful not to track it into your home on your shoes or clothes. Take those shoes off at the door.
  • Don’t groom your pet inside. Cut down on the amount of hair and dander in the air by taking your pet outside to groom them.
  • Keep mold under control in bathrooms, basements, and wherever it may grow.

Will an Air Purifier Help with Cat Allergies? – FAQs

What is the fastest way to get rid of cat dander?

Brush your cat daily with a soft brush, but do it outside.

What neutralizes cat dander?

You can try dander shampoos such as Tropiclean Dander Reducing Waterless Cat Shampoo.

Can I build immunity to cat allergies?

While it’s not unheard of for someone to develop immunity, it’s also possible for reactions to get worse with increased exposure.

Will an Air Purifier Help with Cat Allergies? – Final Thoughts

Yes! An air purifier will help with allergies. 

You don’t need to find a new home for your cat.

Just make sure you have or are planning to purchase an air purifier with a HEPA filter, as this type of filter is guaranteed the highest efficiency. 

And make sure that you purchase an air purifier with a genuine HEPA filter, not a cheap knockoff.

Because the cheap knockoff is guaranteed not to help with your cat allergies!

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