Panera Bread is now serving a "clean bacon" sandwich, as part of an ongoing effort to remove chemical additives from its menu by 2017.

The fast-casual restaurant chain says the meat is now cured using celery powder, in lieu of such chemicals as sodium nitrite, sodium phosphate, and sodium erythorbate. Other changes include brining the bacon in sea salt, sugar, and thyme extract. Served at room temperature, rather than being refrigerated, the slices are now 25 percent thicker--to prevent them from sliding out of a sandwich.

With more customers opting for natural foods, Panera claims that it is the first restaurant chain in the U.S. to take on such a challenge.

"Clean bacon is an example of how you can amplify when you simplify," said Ron Shaich, the company's founder and CEO. "By removing artificial additives, we made a switch to better ingredients, better texture and, ultimately, better flavor. We're not just offering clean bacon; it's bacon that has been elevated in every way."

Of course, it's worth pointing out that the new item isn't necessarily a healthier choice. "Bacon is still bacon," Dan Kish, the company's head chef, told CNBC. "It's from the belly of a hog. It's fatty, it's delicious, but you shouldn't eat a lot of it every day."