As a first step, the firm that makes Doritos and Fritos brands announced the outer layer of packaging on 10.5 oz size SunChips snacks bags will be made with the plant-based renewable material, polylactic acid (PLA).
“To make packaging that would interact differently in the environment we had to change the composition of packaging and invent key technologies,” said Gannon Jones, vice president, marketing, Frito-Lay North America.
In response to growing environmental concerns, consumers are showing increasing interest in packaging that is not destined for the landfill. And in step with this growing movement towards green plastics with sustainability credentials, food firms are gradually adopting new, sustainable materials for their packaging applications, such as PLA made from corn-based ethanol.
As part of the current packaging change on the SunChips brand, Pepsico said the front panel of the current 10.5 oz size SunChips package features the text: “Renewable materials make up 33 per cent of this bag.”
And by Earth day (April 22) 2010, PepsiCo's Frito-Lay North America division plans to roll-out a package for its SunChips snacks where all three layers are made from PLA material so the package is 100 per cent compostable.
Current snack food packaging has three layers: a printed outer layer with packaging visuals and graphics, an inner layer, which serves as a barrier to maintain the quality and integrity of the product, and a middle layer that joins the other two layers.
"When the packaging is 100 per cent compostable, it will fully decompose in about 14 weeks when placed in a hot, active compost pile or bin," said PepsiCo, that claims over the past five years it has reduced the amount of plastic in packaging by 10 per cent, thereby eliminating 12 million pounds of materials annually used to make the snack bags.
PepsiCo, the world's fourth largest food company, sourced its PLA from US firm NatureWorks, itself a joint venture between agro-giant Cargill and japanese firm Teijin.
NatureWorks claims its proprietary polylactide biopolymer, marketed under the brand name of Ingeo, currently uses 65 per cent less fossil fuel resources to produce, and reduces greenhouse gas emissions by 80 to 90 per cent compared to traditional petroleum-based polymers.
Green plastics, also known as bioplastics, are usually fabricated from 100 per cent renewable sources, such as plant-based ethanol and vegetable oil.
Setting out to have the same specifications of petrochemical plastics, plastics made from renewable sources purportedly have a net positive carbon footprint. By contrast, the production of plastics derived from petroleum emits the greenhouse gas carbon dioxide (CO2) into the atmosphere.
It is suggested that recyclable green plastics generally perform better than biodegradable alternatives in sustainability analyses. Biodegradable green plastics are less durable, cannot be easily disposed of because of the need to separate them from conventional recyclable material, and emit the powerful greenhouse gas methane when decomposing in landfills.
On the other hand, green plastics effectively store the CO2 absorbed during photosynthesis for extended periods of time as it is recycled and used in different ways. At the end of their useful life, green plastics can be burned to recover their energy content.
One key obstacle to growth in the bioplastics market, estimated by trade group European Bioplastics as making up 0.20 per cent of the total plastic market in the EU, is what to with them once their useful life is over and whether they end up being landfilled, incinerated or composted.
While bioplastics that are not incinerated or routed to landfill are likely to be composted and should, in theory, be accepted by composters, often they are not out of concern that they could be contaminated with conventional plastics.
Another option could be anaerobic digestion, whereby the packaging could be fed into digesters together with waste food. But there is still limited capacity for this form of disposal, and many bioplastics manufacturers are still conducting tests.