The Tefal we know is a combination of Teflon + Aluminum. This is used as the brand name.
Key content: Never preheat an empty coated frying pan. Doing so will evaporate and produce a poisonous gas called hydrofluoric acid.
So, if you start by putting cooking oil or the food you were trying to cook, it won’t come out. This is the key. Cooking oil does not go above 180 degrees.
Teflon emits hydrofluoric acid when the temperature exceeds 300 degrees, so it prevents cooking oil from exceeding 200 degrees.
For reference, hydrofluoric acid is an extremely toxic substance used in the semiconductor process.