Earlier this year, a blogger warned consumers about azodicarbonamide. Companies used the chemical compound in dough to make bread fluffy. But the ingredient is also used to make yoga mats. So folks flocked to her website to sign an online petition asking companies to stop using the stuff.

Indeed, azodicarbonamide isn’t the only chemical ingredient to be outed online and summarily removed from foods we eat. Two years ago, cochineal extract (a.k.a. carmine), a red dye made from crushed bugs, got the boot from two of Starbucks’ strawberry-flavored drinks. Ditto for brominated vegetable oil, or BVO, a food additive that keeps the color in citrus-flavored soft drinks from separating.

But everything in our environment is made of chemicals, and they aren’t necessarily bad for us. Water is a chemical compound—dihydrogen monoxide—that we need to support life.

Still, some laboratory-produced chemicals added to food to flavor, preserve and confer other functional benefits aren’t really necessary, say health advocates. They want to know why companies don’t just use natural substances from whole foods to accomplish the same results.

Hmm. Good question.