In theory the liner is PTFE (or maybe a different fluoropolymer) with nothing left to leach out. PTFE and its relatives are stable to temperatures well above th

In theory the liner is PTFE (or maybe a different fluoropolymer) with nothing left to leach out. PTFE and its relatives are stable to temperatures well above that of boiling water, so leaching shouldn’t be an issue. (One big problem with PTFE is that it starts to slowly decompose at a lower temperature than its melting point. This makes it messy to work with. As I understand it, the decomposition products are gasses, so this is a problem at the factory and for the environment, but I don’t think its a problem for end users.)