After I used my ABC FE on my oven, and days before the window in front of the oven broke, I realized I could not possibly clean well a continuously cleaning oven. So I called an FE company and asked what if some of the powder fell on the food, and he said, Not a problem.
Huh. I wonder what that was. My cheap kidde ABC, about as big as a small propane gas tank for a hand held torch, that sprays powder was used on the top of the oven too, but didn't damage anything. The range hood is still fine, the radios in the room, the tv.