I am afraid you are mistaken. It is perfectly OK to feed regular potato peels. What is a no-no is to feed the GREEN potato peels. The GREEN in the potato peel indicates a presence of solanine that is poisonous to humans and chickens. The GREEN potato peels can be on regular potatoes or sweet potatoes. Sunlight concentrates the solanine to a dangerous level and turns the skin green.
It is not that othey are going to fall over dead the instant they take one peck of a green potato peel. I don't know what the fatal dose is, but I don't feed the green ones at all. I do feed the others and don't worry about it.