Biodegradable plastics often are touted as having all the benefits of conventional plastics with fewer of the environmental downsides. But one plastics recycling trade group is wondering if biodegradable bottles could do some unexpected environmental harm.
The Association of Postconsumer Plastic Recyclers said it is concerned that the biodegradable bottle could hurt the environment by making it more difficult to recycle existing PET and high density polyethylene bottles.
The group's message prompted California officials to put the brakes on a legislative proposal that would have given companies using the biodegradable bottles more flexibility complying with one of the state's plastics container recycling laws.
Arlington, Va.-based APR is not saying that biodegradable bottles definitely will cause problems, but Executive Director Robin Cotchan said the industry has questions.
Preliminary data raises concerns that the different melt temperatures of biodegradable plastic may cause problems during manufacturing and that mixing it with PET could leave PET bottles cloudy.
``If the inclusion of degradable plastic with normally recycled plastic hampers the reclaiming process or renders the recycled PET and HDPE unfit for its uses, the environmental consequences of the biodegradable plastic bottle would be strongly negative,'' APR said in a news release.
Cotchan said APR received a presentation of performance data of biodegradable polylactic acid-based resin from manufacturer Cargill Dow LLC.
Cargill Dow said the presentation did not address recycling, but rather outlined general performance characteristics of the material.
Cotchan said the group does not have data from commercial testing but is trying to develop that, and it would like Minnetonka, Minn.-based Cargill Dow to go through the group's Champions for Change process to evaluate the material for recyclability.
``With reputable and complete data, APR could then form an opinion about the compatibility of biodegradable plastics and recycled PET and HDPE,'' APR said.
``While we do not have definitive statements on the compatibility of biodegradable bottle materials and either PET or HDPE, we are seeking to confirm the chemical compatibility of the biodegradable plastics.''
Cargill Dow spokesman Michael O'Brien said his company has not run recycling tests on biodegradable bottles because it is not close to commercializing any, and isn't even clear what bottle markets it may go into.
``It's so wide open in terms of where this bottle could and couldn't go,'' he said. ``If you have a milk bottle, that's one problem. If you have a water bottle, that's another problem. The challenge is we need to define what market we have.''
The California proposal came from state Sen. Betty Karnette, D-Long Beach. It would have allowed companies to use biodegradable containers to comply with California's rigid plastic packaging container law.
The RPPC law requires companies to use recycled content, source reduce the packaging or take other steps if the plastic recycling rates fall below certain levels. Karnette's proposal would have added biodegradable containers to the list of options.
But a Karnette aide, who spoke on condition of anonymity, said that office has received complaints from recyclers, including APR, and has put the legislation on hold.
``We definitely don't want to mess with the recycling system in California,'' the aide said. ``It is working very well.''
Karnette proposed the law because plastic packaging is a significant part of the pollution in the Los Angeles drainage basin and along the ocean front, and she wanted to create an incentive for companies to use biodegradable material, the aide said.
``The senator is very concerned with improper disposal of trash, particularly plastics, because they don't break down,'' the aide said. ``We don't want to mess with the recycling stream but we want to do something about improper disposal.''