Do Biodegradable Plastics Really Work?
The answer, plus five more degrading questions.
Just how long does it take for conventional plastics to completely break down? 500 years? 1,000? It's a mystery. "No one has really measured how long it takes," says Ramani Narayan, a professor of chemical and biochemical engineering at Michigan State University. What is known is that conventional petroleum-based plastics never really go away, even when they break down into pieces too small to be seen with the naked eye. Some new plastics are designed to degrade (not to be confused with biodegrade—more on that in a sec) in a matter of weeks when exposed to the elements, but that doesn't mean they're truly gone.
But broken down plastics are better than litter, right? Wrong. In fact, plastics often create more environmental harm when broken down than when intact. This is most evident in the oceans, home to billions of pieces of disintegrating plastic and preproduction pellets called nurdles, which can work their way back up the food chain to humans.
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What about biodegradable plastics? They're pretty neat: Microorganisms can convert biodegradable plastics into water, carbon dioxide, and biomass—with no nasty chemical leftovers. However, there is a lot of confusion surrounding these ecofriendlier plastics—some of it intentional. "This word 'biodegradable' has become very attractive to people trying to make quick bucks on it," explains Narayan, who helped develop biodegradable corn-based plastic. Some companies, he says, are making conventional plastic that degrades quickly and then throwing around claims about biodegradability that are unproven or just too good to be true.
Can biodegradable plastics break down in landfills? This claim, which now shows up on everything from water bottles to trash bags to Discover's "biodegradable PVC" credit cards, is "disingenuous at best," says Narayan. Usually, nothing biodegrades in a landfill. But if biodegradable plastics do break down in this oxygen-free environment, they'll emit methane, a greenhouse gas 23 times more potent than CO2.
How do I avoid fake biodegradable plastics? Currently, truly biodegradable plastics are mostly used for eating utensils, food containers, and compostable bags. To make sure you're getting the real deal, look for products with the Biodegradable Products Institute logo, which means they've been certified to comply with strict scientific standards.
So what's the best way to get rid of biodegradable plastic? "The public thinks that biodegradability means 'If I throw it away, it will completely go away,'" says Narayan. "They don't even know what 'going away' means." Real biodegradable plastic should be sent to a commercial composting facility, where it will spend its final days being eaten by microbes. But here's the catch: In 2007, only 42 communities nationwide offered compost collection. (Seventeen were in California.) And though some biodegradable plastics can be recycled, no curbside recycling program will take them. So before you buy biodegradable plastics, make sure you can help them "go away" the right way.
Comments
BIODEGRADABLE PLASTIC
Submitted by Max Clark (not verified) on Tue Apr. 21, 2009 11:11 AM PDT.
All the talk about what is and what isn't biodegradable is confusing to consumers. For example, PLA (Corn based plastics) seems like a good idea but it isn't the fix all solution. PLA doesn't biodegrade in a landfill environment and must be processed by commercial composting sites. The problem with that is that commercial sites are far and few between. Still, there is a need for innovative plastics like PLA. There is also a need for other innovative plastics if we ever want to truly reduce/eliminate plastic pollution. Oxo-Degradables do break down into smaller and smaller pieces...never going away, just getting smaller. That's not good for us or our planet. Biodegradable PET plastic bottles do break down in a landfill environment through microbial digestion and don’t leave behind plastic residue. That's not the fix it all answer either, but it is a step in the right direction. It would be good if those involved in the plastic industry started working together....then maybe we could have a "Healthier Earth."
Biodergadables and Global Warming
Submitted by Anonymous (not verified) on Fri May. 1, 2009 10:51 AM PDT.
Any plastic made from fossil fuels that simply gets smaller and smaller without decomposing is a small amount of carbon sequestered from being burned and released into the atmosphere. Shouldn't we be encouraging MORE of this? End global warming at all costs! Plus, corn based plastics are part of the massive, industrial, polluting agrochemical complex. Carbon neutral my butt. Is it possible to make corn based plastics that don't biodegrade? Then we could just take carbon out of the atmosphere and bury it.
;-)
What happens when we run out
Submitted by Talk About Not Being A Solution! (not verified) on Wed Sep. 16, 2009 9:13 AM PDT.
What happens when we run out of land in the United States to bury it all? What then?
Plastic
Submitted by Anonymous (not verified) on Fri May. 1, 2009 11:14 AM PDT.
I honestly think we should take recycled plastic and remold it into manmade Icebergs. We could implant them with GPS devises and release them into the Artic. If we structured them correctly, the polar bears could use them the way they used to use real icebergs, giving the bears solid, not melting away in the heat, perches to hunt seals from. Ships could locate them by using GPS locators and avoid potential Titantic impacts. If the (plastic) icebergs drifted too far south, they could be airlifted or towed back north. I understand that not all the plastic we produce could be recycled this way, but at least some of it could be put to good use.
the idea sounds cool :-) but
Submitted by Anonymous2 (not verified) on Wed May. 6, 2009 1:52 AM PDT.
the idea sounds cool :-)
but you are kidding, right?
Actually....
Submitted by Anonymous (not verified) on Fri May. 1, 2009 11:49 AM PDT.
I have been composting corn/potato starch plastics for over a year at home and they are breaking down just fine. It takes a while, but not as long as coconut shells... It's a myth that they must be sent to a commercial facility. If you have a strong paper shredder (that cuts credit cards), it speeds up the process to grind them down first, but it's not necessary.
Home compost piles can get very hot
Submitted by greenknight on Sat May. 2, 2009 2:32 AM PDT.
The claim is that only large-scale commercial composting gets hot enough to break the stuff down, but it ain't necessarily so. If you just throw stuff in a heap, dampen it down, and wait six months, that won't do it. If you get the ratio of carbon to nitrogen right, get the moisture level right, have a large enough pile (between 3 an 6 feet wide and tall, and as long as needed), and turn the pile whenever the internal temperature begins to decline, you can achieve just as high temperatures and break down everything just a thoroughly as any commercial plant.
It's a lot of work, and not all home composters do it; but it is achievable.
The problem is getting worse
Submitted by Ashwood University (not verified) on Mon Jun. 8, 2009 10:41 PM PDT.
The problem is getting worse day by day and it won't be solved until everyone involved with plastics....consumers and manufacturers....work together. For me it's that simple, we work together or get smothered by tons of plastics or their related pollution problems.
out of sight out of mind
Submitted by Tara on Tue Sep. 15, 2009 7:04 PM PDT.
In response to the composters, I think it is very important to remember that the biodegradable isn't gone just because we can not see it anymore. There could be changes happening in the compost due to this new material, and we must continue to question cause and effects of this product. It is a product of the chemical industry and is not an organic thing that has a place in an organic system, allthough we humanitarians hope that science and technology will produce safe green products.
Biodegradable or Compostable?
Submitted by Max Clark on Wed Sep. 23, 2009 10:35 AM PDT.
Interesting information. Bioplastics probably do have a place in the plastic industry as a niche market. I shudder to think of the ecological disaster we would be faced with if PLA was manufactured in the quantities of today’s standard plastics. Certifying any plastic to be biodegradable through BPI is confusing. BPI by its name indicates that it is certifying for biodegradability. BPI is sponsored and funded by the PLA industry and has played a key role in developing ASTM 6400. PLA plastics aren't biodegradable, they are compostable. BPI should probably change its name to CPI...Compostable products Institute...this would reduce consumer confusion. ASTM 6400 isn't about biodegradation.....it’s about compost ability.
My real concern with PLA here in the U.S. is that most of it is made from corn. I believe that using corn isn't all that friendly; It increases pesticide usage, reduces food grain supplies, contributes to rising food prices, and is contributing to the loss of our rain forests ( Countries that relied on grain imports from the U.S. are clear cutting/burning down the forests to grow corn). PLA corn isn't doing this all by itself...the same corn is also being used for subsidized ethanol. There are a host of other problems associated with corn/soybean PLA.
I would be more comfortable with PLA if it was made from a non food source such as algae.
Max
http://www.ensobottles.com
Algae oil in plastic resins
Submitted by Anonymous (not verified) on Fri Dec. 18, 2009 8:56 AM PST.
Algae is renewable, does not affect the food chanel and consumes CO2. The National Algae Asssociation www.nationalalgaeassociation.com is willing to work with any plastic resin manufacturer to use algae oil in their process.
bioplastics
Submitted by Anonymous (not verified) on Mon Jan. 25, 2010 7:41 AM PST.
Thanks for this informative article. It's so hard navigating through the sea of misinformation when you are trying to do the right thing for the environment.
ty
Submitted by Anonymous (not verified) on Mon Feb. 8, 2010 2:41 AM PST.
mr catton says i should use this website THANKS!
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