PVC / EPDM pondliner in the bontanic cell in a earthship

Hi i soon come to install/build my botanic cell / greenhouse bed in my Earthship. But i can not find locally EPDM liner only pvc. And only in 0,5 and 1mm thick the old book recommends a 2mm EPDM liner. Any in here have experience with using PVC liner will they last ? are they toxic ?

If any know were to buy a EPDM liner in Portugal ore west Spain i´m all ears. (online order is not that easy since it´s a 80 kg packed, )

Maybe these guys:
https://agriloja.pt/produtos-lista/produtos-agricultura/

At least call them and ask them to refer you to someone else.