A -- PTFE can not tolerate a very strong reduction atmosphere, molten alkali metal, ammonia solution (alkali metal dissolved in liquid ammonia,some fluorides (such as TFA), naphthalene sodium salt and so on can quickly corrode PTFE products.
-- PTFE is stable in nature, but attention should also be paid to eliminating high temperatures, -especially avoiding exposure to open flames, it will release toxic gases when the temperature above 400 degrees Celsius.