Frito-Lay is releasing SunChips in new packaging this month as one step towards eventually packaging snacks in fully compostable bags.

The company's new 10.5-ounce SunChips bags are made with 33 percent polylactic acid (PLA), a corn-based biopolymer. The PLA makes up the chip bags' outer layer, one of three layers in the bags.

Frito-Lay is usingNatureWorks'Ingeo PLA, and plans to have a chip bag made of 100 percent PLA on store shelves by Earth Day 2010. The fully compostable bags would be able to decompose in hot, active compost piles or bins within 14 weeks, Frito-Lay says.

As part of its marketing push for the new bag, Frito-Lay will include samples of the bags in a People magazine ad.

Although bioplastic technology has advanced to the point that biopolymers can be used in a wide range of packaging and products, one of the barriers to its usefulness as a material is the lack of widespread, easy access to composting. Most bioplastic needs to be composted in industrial compost facilities; some can also be composted in home compost bins and piles.