Environmentally driven policies that give preference to certain packaging polymers, chiefly polyethylene (PE) and polyethylene terephthalate (PET), are eroding demand for other plastics, converters report.

Marks & Spencer favours PET, PE and polypropylene (PP) because they are "easy to recycle" and Sainsbury has said it believes nearly all of its primary pack requirements for food and drink can be met by these three polymers. M&S is also among those that favour polylactide (PLA) for its compostability.

M&S's long-standing policy to avoid the use of polyvinyl chloride (PVC) is being taken up by other retailers.

"Tesco and Asda are getting rid of it, having not previously been bothered about it, and are converting to PET," says packaging firm Anson's national account manager Melanie Williams. She adds: "There is also less and less demand for polystyrene (PS), unless it's for freezer applications, where PP can't be blast-frozen."

Sharp Interpack is now producing its range of soft-fruit punnets using at least 60% recycled bottle PET. "This is an environmental material substitute that can easily replace standard PET or PVC," says European business manager Mark Tollman.