Tuesday
15Sep2009
Compostable and "Biodegradable" Plastics Provide False Sense of Responsibility
Tuesday, September 15, 2009 at 06:40AM It seems everywhere I go these days, another restaurant is serving drinks in “biodegradable” plastic cups and food with potatoware disposable cutlery. And it really bugs me. But why would I be against making wasteful disposable plastic a little greener, you ask? Because without coupling the use of these biodegradable plastics with the ability to recover them, we are reinforcing a false sense of responsibility that we are doing good by the environment when we really aren’t. If the composting infrastructure is not in place to recover the bio-material from that corn-based cup, it’s really no better than the ubiquitous red plastic keg cup… more
tagged bioplastics, compost, plastic in Recycling
bioplastics, compost, plastic in Recycling 
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Reader Comments (1)
“Compostable” plastics are too expensive for everyday use, and there are very few composting facilities. Also, as it is difficult to separate compostable plastics from other plastics, many industrial composters do not want plastic of any kind in their feedstock, and it is not suitable for home-composting. Compostable plastics damage the recycling process if they get into in a normal plastic recycling waste stream.
Plastics from corn do not have a smaller carbon footprint than conventional plastics – consider the hydrocarbons burned by the machines which clear the land, plough and harrow the land, make the fertilisers and pesticides and bring them to the land, sow the seed, harvest the crop, take it to the factory, and run the autoclaves. Ordinary plastic has a better LCA than “compostable” plastic (http://www.kunststoffverpackungen.de/en/news/LCA%20waste%20bags%20-%20Study%20Extract%20B.pdf)
Land and water should be used to grow food, not to make plastic. Also as they are thicker and heavier than normal plastic “compostables” need more trucks to transport them, using more diesel fuel and occupying more road and warehouse space.
Compostable plastics are required by the composting standards (ASTM D6400; EN 13432 etc.) to convert themselves to CO2 gas in 180 days, so they contribute to climate change but do not improve the soil.
If buried deep in landfill,compostable plastics will emit methane Decomposition of anything is undesirable in landfill unless the landfill is designed to collect the gas, which most are not.
Ordinary or recycled plastic, and compostable plastic, will not readily degrade in the open environment, but plastic can now be made oxo-biodegradable.
This is done by including a d2w formulation which breaks the molecular chains within the polymer and makes it degrade then biodegrade in the presence of air, on land or at sea, in the light or the dark, in heat or cold, leaving NO methane, and NO toxic dust or any other harmful residues. Oxo-bio (www.biodeg.org) can be tested according to American Standard 6954, and is certified safe for food-contact. Plastic is made from a by-product of oil refining which used to be wasted, so nobody is importing extra oil to make it. Oxobio can be recycled, and made from recyclate, and there is little or no additional cost.