Where did you read this? What I’ve read has said the opposite. Here’s one result for “teflon flakes”
When cooking, flakes of Teflon can break off into food. If these flakes are ingested, it is considered non-toxic.
If metal utensils are used with Teflon coated cookware, small pieces of Teflon can break off and get into the food. This is considered non-toxic. When swallowed, these pieces will travel through the intestines and come out in the stool intact without causing harm to the body.
Where did you read this? What I’ve read has said the opposite. Here’s one result for “teflon flakes”
https://missouripoisoncenter.org/is-this-a-poison/teflon