Stand-up pouches (SUP) like this are typically made with laminated polyethylene terephthalate (PET), polyester, and low density polyethylene (LDPE). The laminated structure may be labelled (PET/PE) and is not recyclable. Pouches made with mono-layer LDPE, welded to create an airtight barrier, can be recycled. The reason LDPE is laminated with other plastics, like PET, is to increase barrier properties, such as oxygen and odour.