Makers of air purifiers like to say their products kill airborne germs and filter dust, smoke, pollen, and other allergens from your home. We at Consumer Reports don’t recommend  buying an air purifier unless you or a family member has allergies or asthma and you’ve exhausted all other remedies. Our new video will help you decide if you really need one.
 
If you're shopping for an air purifier, you may notice an Association of Home Appliance Manufacturers logo with a set of three numbers for tobacco smoke, pollen and dust. Most room air purifiers are certified by AHAM as part of a voluntary program that includes clean-air delivery rate (CADR)—the volume of filtered air delivered by an air cleaner. We judge CADR above 350 excellent and below 100 poor. AHAM also lists appropriate room size. For better cleaning at a quieter speed, choose a model certified for a larger area than you require.

There’s no agreed-upon yardstick for removal of  irritants other than tobacco smoke, pollen and dust. And manufacturers that make medical claims for their air cleaners often draw the scrutiny of government authorities.
 
—Ed Perratore
 
In the market for an air purifier? Check out our buying advice. Subscribers to ConsumerReports.org can view our Ratings for portable and whole-house models.