How Long Does it Really Take Plastic to Decompose?

How long Does it really take plastic to decompose?!

For 20 years I have avoided this question because I knew the answer would destroy my favourite post kayaking tradition - eating 100lbs of hand cut fries covered in squeeky Quebec cheese curds and smothered in thick, dark gravy.  If you’re not familiar, this French Canadian delicacy is known as Poutine.

And it’s amazing.

And the absolute best Poutine is found at roadside chip trucks that serve said poutine in a plastic styrofoam container, with a plastic lid, in a plastic bag with a plastic fork and disposable napkin.

And when you’ve spent the 5 whole minutes it takes to eat this God given treat, the container, lid, bag and fork end up in an overflowing garbage can where it will be trucked to a landfill  - not a recycling plant - and sit and sit and sit for 100 years, 1,000 years… forever?

So you can understand why I didn’t really want to know how long it takes plastic to biodegrade because the truth would render this joyful activity a little less so - until... I couldn’t really avoid it (check out our story for more on my ‘awakening’).

But I figured if I could face the truth about plastic, you could too.

And here’s the thing - decomposition, compostability, biodegradability - is largely dependent on microbes, tiny organisms that are invisible to the naked eye.  Despite their teenie size, these guys play an enormous role in cleaning up our planet, but because plastic is made up of compounds that don’t naturally occur in nature, microbes turn their nose up at plastic, they simply won’t eat it.   

Plastic does not decompose... ever!

Which means, according to Popular Science, plastic does not decompose, biodegrade or compost, rather it just breaks down into smaller and smaller plastic pieces.

"Plastics don't biodegrade like organic matter, which means they can't be converted by living organisms into useful compounds for life. Instead, they photodegrade, a process by which photons from the sun's rays pulverize the plastic polymers until they are broken into individual molecules." (Popular Science)

And this is why there are huge masses of plastic floating around our Oceans (some Scientists like Ellen MacArthur even believe that by 2050 there will be more plastic in our oceans than fish) and lakes, clogging our landfills and even leaching toxins into our water table.

Great, so microbes can’t eat plastic, therefore plastic is bad, right?


Ish you say?  What’s this ish… please explain.  

Well, you see, plastic’s inability to biodegrade is definitely problematic, but just how problematic depends on its use - and reuse - because the term plastic refers to everything from the steering wheel of your car to the grocery bag you used to drag home those delicious organic berries (and that 10 pound sack of cheesies).

In fact, some would argue that the plastic used in car manufacturing actually provides a net benefit to the environment because it is lighter than steel and makes cars more fuel efficient and therefore burns less fossil fuels.

Grocery bags, plastic wrap, sandwich bags, ziplock bags and produce bags are more troubling because they are typically used once - maybe twice - and then discarded, where - as previously established - they will wind up in a landfill or somewhere out in the wilderness where they will never biodegrade.  

And this begs the question that we - the consumers - must face.  Is the ease of use of plastics like grocery bags, styrofoam containers or disposable forks really worth the cost?  

Now you know that those single use plastics cannot decompose, what are you going to do about it?

While you're here, check out our Plastic Free Club and join a like-minded community that helps our team and other members to do more to go plastic free?

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  • While plastic does not decompose it does, as you note, break down over time into smaller and smaller pieces. And when it does so, that is even worse — indeed, much worse — for the marine environment, than all the much photographed and talked about plastics despoiling coast lines or bobbing up and down and floating round and round in the gyres.

    As plastic degrades and breaks into smaller and smaller pieces, both fish and marine mammals mistake it for food and eat it. But wait… it gets even worse than that (from the human perspective at least). Plastics floating in the ocean are highly adsorbent — meaning in this case that they act like mini-magnets for other chemical pollutants dumped into the ocean from sources such as agricultural run off and industrial waste. The fish, in other words, are consuming tiny plastic poison pills. What proportion of fish are affected? I don’t think that has been fully determined yet. But of the well over 200 species tested so far ( maybe quite more than that by now… my knowledge of it is a bit dated) all of them — including those we most commonly eat — tested positive for plastics. What goes around comes around and the contaminants with which we’ve despoiled the ocean return to us in a perverse kind of poetic justice.

    So as the poster before me asked, what to do about it? We are, like it or not, a plastic world now. And as that poster correctly noted, some uses for plastic — such as in automotive technology -are beneficial. The biggest part of the problem is with consumer disposable plastics: the stuff we use once or twice and then throw away - plastic bags, bottles, straws, cups and yes, plastic wrap.

    Better recycling regimes (and Western Europe is way ahead of the U.S. on these) would help, of course. But even these only address a tip of the plastic iceberg. Why? Because of the millions of tons of plastics entering the ocean every year, the vast majority - up to 80 or 90%- now comes from the developing world — from Asia (with China as the #1 offender), Africa and to a slightly lesser but still very significant extent, Latin America. These are countries that don’t have even basic waste collection, management and storage (e.g. landfills) facilities. So the first step, in my view, is helping and encouraging them to build those facilities. It’s not rocket science: It can be done. And for those who are interested in learn how, I’d suggest you check out and other NGO websites focusing on this issue. Anyone genuinely interested in this issue is welcome to shoot me an email at

    Michael Ross on
  • I try never to use plastic. I take cloth or paper bags to the grocery store and tell clerks that I never use plastic (they appear totally unimpressed. The American public is completely ignorant about this.) The only thing that will work is taxing the use of plastic. The problem is, so flippin’ many things you get at the grocery store are encased in plastic boxes. I’ll continue trying to circumvent these. This is a Big Oil issue, of course. I think at least one of the big corporations – Shell, or Exxon, or Bp or whatever – announced they were upping their production of plastic. These corporations are hellbent on profit at the expense of life on Earth. Corporations have no soul. They are driven only by the imperative: MAXIMIZE PROFITS. Therefore the real solution is the end of capitalism.

    Ellen Cantarow on
  • Some forward-thinking municipalities and counties in the US – however few, such as Alameda County, CA which includes Berkeley and Oakland – have banned disposal plastics for food service and require compostable materials across the board.

    Elizabeth Bertani on

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