The Environmental Protection Agency says the active ingredient in oven cleaners is lye, which does an effective job to break down grease and grime, but is extremely corrosive and can burn skin and eyes. It's also potentially fatal if swallowed. Instead of using chemical products where you prepare food, try this nontoxic way to keep your oven clean. First, set the self-cleaning mode so it gets very hot and naturally breaks down all the grease and grime into a darkened ash. Allow the oven to completely cool. Then mix a few cups of baking soda with a squirt of dish soap and a splash of white vinegar. Apply this mixture with a sponge to scour away the baked-on mess for a sparkling clean oven.