Americans munch 52 quarts of popcorn per person in a year, according to the American Popcorn Board. That’s 16 billion quarts, enough to fill the Houston Astrodome ten times and spill some into the parking lot. But if microwavable popcorn is your favorite type, here are four health risks to consider before you dig in.

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1. Perfluorooctanoic acid (PFOA). Also found in the coatings on some nonstick cookware, the inside of pizza boxes and fire-fighting foam, this chemical is used in the linings of some microwave popcorn bags to prevent oil from soaking through the paper. Exposure in people who live or work near plants that produce PFOA has been associated with kidney and testicular cancers, Emory University scientists reported in 2013. It may also be associated with infertility in women according to a University of California Los Angeles study. And a 2012 Harvard School of Public Health study found that it may reduce the effectiveness of some childhood vaccines.

How to avoid it: Many major brands, like Jolly Time, Orville Redenbacher and Newman’s Own Organic Pop’s Corn, use PFOA-free bags. So do some smaller brands like Quinn and Snappy. Check labels. Under a U.S. Environmental Protection Agency program, the use of PFOAs is to be phased out of almost all products by the end of 2015.

Or pop your own. Grab a bag or a jar of popcorn kernels at the supermarket and haul out your air-popper. Or follow package directions for popping in a skillet or pot.

2. Trans fats. Linked with heart disease, stroke and diabetes, these “Franken fats” are still found in many microwave popcorn varieties. The American Heart Association recommends keeping your consumption to no more than 1 percent of total daily calories, equal to about 2 grams if you eat 2,000 calories a day. (The Dietary Guidelines for Americans 2010 and the Institute of Medicine recommend keeping consumption as low as possible.)But flavors like Pop Secret’s Extra Butter have 5 grams of trans fats — in just one-third of a bag. Jolly Time’s Jalapeno Butter Spicy Popcorn has 5 grams in a serving equal to about two-fifths of a bag.

How to avoid it: Read the Nutrition Facts panel on the box. Most brands have products with zero trans fats. Or pop your own in a skillet or air-popper for a zero trans-fat treat.

3. Saturated fat. This is stuff that clogs arteries and raises “bad” LDL cholesterol. The American Heart Association recommends keeping your saturated fat intake low — about 16 grams per day if you eat 2,000 calories per day. But if you’re a big popcorn fan, you could get that much from one bag of some types of microwave popcorn, including store brands.

How to avoid it: Look for saturated fat on the Nutrition Facts panel. Most microwave popcorn brands offer lower fat choices. Or make your own. Air-pop it, then sprinkle with herbs and spices instead of butter.

4. Sodium. We know — what’s popcorn without salt? But if you’re trying to reduce your sodium intake to help control or prevent high blood pressure, microwave popcorn can be a salt bomb worth sidestepping. A single serving (usually about one-third of a bag…but who stops there?) may contain up to 380 milligrams of sodium. Munch the whole bag and you’ll have eaten more than half of the total you should get in a day. (The American Heart Association recommends a daily limit of 1500 milligrams.)

How to avoid it: Look for a lower-sodium variety — many brands offer healthier types with less sodium and fat. Or make your own and top with a reasonable amount of salt or sodium-free seasonings.

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Sari Harrar is an award-winning health, medicine and science journalist whose work appears in Dr. Oz The Good Life magazine, Good Housekeeping, O--Oprah Magazine, Organic Gardening and other publications.