Allergy sufferers were unconvinced recently when the Canadian government ruled that existing HEPA air purifiers on planes, combined with effective air circulation, adequately protect passengers from cat dander. The government transportation agency ruled that the airlines must also provide those who self-identify as allergy sufferers with at least five rows of separation from onboard cats. But the agency refused an outright prohibition on cats brought aboard airliners, noting that modern airliner cabins have 20-30 air exchanges per hour, a much higher rate than office buildings or homes. In addition, the agency noted that the HEPA air filters on planes are effective at removing 99.97 percent of all particles that pass through them.

The case in Canada points out just how touchy the issue of cat dander can be for allergy sufferers. As many as 36 percent of all American homes have at least one cat, according to surveys, and as many as 10 million Americans suffer from allergies to cat dander. More than twice as many Americans are allergic to cats as to dogs. Those allergies can cause a wide range of symptoms, from runny noses and sneezing to extreme asthma attacks and hospitalization or even death. Chest X-rays of people exposed to cat dander show that the dander can cause nodules to form in the lungs, reducing lung function and causing permanent lung damage as a result of long-term exposure. So when it comes to cats and allergies, emotions can run at high speed.

Allergic reactions caused by cats is mostly the effect of cat dander, not cat hair. The dander is old skin scales that have flaked off and become airborne. Even in homes where there are no cats there can be cat dander, because it’s carried in on clothing. And if you have moved into a home where a pet has lived, it can take a year or more until the pet dander present there will lose its potency.

Of course, cat dander can’t irritate your respiratory system unless you breathe it in, and that it means it must be airborne. Unfortunately, cat dander is so light and small that it easily becomes airborne. About 75 percent of cat dander particles are 5 to 10 microns in diameter – far smaller than the diameter of a single human hair. But about 25 percent of cat dander particles floating in the air are smaller than 2.5 microns. They rarely settle down on surfaces and, even when they do, they are easily relaunched into the air.

There is a solution. A high-performance air purifier such as the IQAir HealthPro Plus with HyperHEPA filtration can clear almost all (in many cases,all!) of the cat dander from indoor air. “Since cat allergen is so difficult to remove, a good HEPA air purifier is essential,” says one expert website. Most agree – a HEPA air purifier will often completely eliminate the allergic symptoms that cat owners with allergies are contending with. That means a house can be a happy home for both cats and their owners alike.