A lifecycle analysis published by the American Chemistry Council (ACC; www.americanchemistry.com) suggests that PS cups and plates use significantly less energy than comparable corn-based products but generate more greenhouse gas emissions.

The lifecycle inventory and greenhouse gas emissions study, conducted by US consultancy Franklin Associates (Prairie Village, Kansas / USA; www.fal.com), calculated the energy consumption, water use, solid waste and greenhouse gas emissions of average-weight PS foam, PLA cups and paperboard used for hot and cold drinks, plates and sandwich containers.
The study found that PS foam products consume significantly less energy than the alternatives – half as much as wax-coated paperboard cups and one-third as much as the PLA sandwich containers, the ACC said. The PS foam products were also found to use less water and create less solid waste than the alternatives.

However, PS foam products generate slightly more greenhouse gas emissions than PLA products, according to the study. Comparison with paperboard products was complicated by the fact that the greenhouse gas emissions from paperboard products varied widely depending on the extent to which they degrade.

The researchers noted that no foam PLA products were available, and therefore the PLA products analysed were solid PLA cold cups, plates and sandwich containers and PLA-coated paperboard hot cups.

e-Service:
Study "Life Cycle Inventory of Foam Polystyrene, Paper-based, and PLA Foodservice Products" as a PDF document