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If you live on planet Earth and need to eat, you’ve probably read stories recently about azodicarbonamide, a chemical used as a food additive and in the production of foamed plastics (think: yoga mats and shoe soles).

The Internet has been abuzz about azodicarbonamide since a food blogger named Vani Hari launched a petition asking Subway to ban it from eight of their breads that contain the additive. Within days, Subway vowed to stop using it.

So what was that chemical in your Cold Cut Combo, and is it dangerous?

What exactly is azod . . . eye-zod . . . How do you say it?

Azodicarbonamide (pronounced eye-zo-die-car-BON-amide) is a manufactured chemical compound that can be used as a foaming agent in the production of a variety of plastics; but it can also be used in the production of baked goods like breads and cereals. At room temperature, azodicarbonamide looks like an orange, crystal-like powder.

Why would anyone put a plastics foaming agent in food?

Because it “results in increased loaf volume, finer grain, softer texture and superior dough-handling qualities,” among other things. The American Bakers Association told CNN that “as a dough conditioner, it has a volume/texture effect on the finished loaf. It is a functional ingredient that improves the quality of bread.” The food is listed as “Generally Regarded as Safe” by the United States Food and Drug Administration (FDA).

Do other countries agree with that assessment?

Not all. Use of azodicarbonamide as a food additive is prohibited in Australia and Europe. The World Health Organization has expressed concern that it may be linked to respiratory issues. According to the Chicago Tribune, “in Singapore, use can result in up to 15 years imprisonment and a fine of $450,000.” (But Singapore is pretty tough when it comes to punishing offenses.) Canada allows the use of azodicarbonamide in food.

Do other restaurants use azodicarbonamide? And in what types of foods?

Yes, plenty. An NBC news report listed McDonald’s, Burger King, Wendy’s, Arby’s, Jack in the Box and Chick-fil-A among the restaurants whose food contains azodicarbonamide. The compound usually shows up in soft breads or sandwich buns.

OK, I’m kind of freaking out right now. I’ve definitely eaten at those restaurants. Give it to me straight—how long do I have to live?

Relax. The FDA has found the compound to be safe, and although its “Generally Regarded as Safe” designation has recently come under fire, to date no study has  linked consumption of azodicarbonamide to any adverse effects in people. The WHO study (the main one cited by Hari) notes that oral exposure can lead to infection of the kidneys in “several species”—i.e., not humans—and that the infected kidneys occurred in animals that had oral exposures over 200 mg of azodicarbonamide per kilogram of body weight for up to a year.

By comparison, FDA regulations state that manufacturers cannot use more than 2.05 grams per 100 pounds of flour. That’s less than a 10th of an ounce per 100 pounds.

The same WHO report cites respiratory issues like asthma among some people who were exposed to azodicarbonamide. But those individuals were breathing in the compound, not ingesting it.

Even so, I really don’t want to have to worry about eating stuff like this at lunch.

That’s a fair point. And it’s probably why Subway announced it will stop using azodicarbonamide.  “We are already in the process of removing azodicarbonamide as part of our bread improvement efforts, despite the fact that it is [a] USDA and FDA approved ingredient,” Subway said in a statement.

What about all of the other restaurants that use azodicarbonamide?

We’ll have to wait and see if they drop it, too—and if Hari takes aim at them. Her petition to Subway garnered 88,000 signatures within a week.

Should I lose sleep over this?

Over the foods containing azidocarbonamide that you’ve eaten in the past? No. But it is always a good idea to pay attention to the ingredients in your food. “The less processed, the better” is a good general rule of thumb.