A lot of people don't know that about teflon, if it over heats it gives off some gasses that will basically kill the bird in a very short time, once they are exposed to the fumes, nothing can be done.
It's also deadly to many other birds, African greys are especially sensitive to lot's of regular household stuff, like deodorants, oven cleaner stray, and tobacco smoke to name a few, but teflon can be deadly to most birds.