homehome Home chatchat Notifications


Biodegradable plastics don't break down in the ocean, U.N. says

According to a 179-page report released by the U.N., biodegradable plastics degrade far too slow in the oceans, voiding any apparent practical benefit. In the ocean at least, they're just as bad, if not worse in some instances, than traditional plastics.

Tibi Puiu
May 25, 2016 @ 4:25 pm

share Share

A lot of people are attracted by biodegradable packaging because the they feel these are more environmentally friendly. But this is actually debatable. Yes, a biodegradable bag will break down in a couple of months versus hundreds of years as is the case with its synthetic counterpart. However, for this reaction to happen, oxygen and light is required, both in low supply once biodegradable packaging reaches the ocean. According to a 179-page report released by the U.N., biodegradable plastics degrade far too slow in the oceans, voiding any apparent practical benefit. In the ocean at least, they’re just as bad, if not worse in some instances, than traditional plastics.

plastics ocean

Credit; Pixabay

“Weathering and oxo-fragmentation is enhanced by exposure to UV irradiation. The process becomes extremely slow once this is removed, as in much of the ocean. Plastics marked as ‘biodegradable’ do not degrade rapidly in the ocean,” the report reads.

Plastics are carbon-based polymers (long-chain molecules that repeat their structures over and over) and we make them mostly from petroleum. They’re very versatile and durable, so there’s no wonder these have been employed to an ever growing extent since the ’50s. The problem we have with plastics today is that they’re too good — too durable, to be more precise. That wouldn’t have been a problem if society didn’t use an extremely resilient material for disposable applications like packaging, wraps and bags.

That’s why biodegradable plastics entered the picture. Instead of petroleum products, which have very strong bonds that are hard to break chemically, biodegradable plastics are made out of natural material like corn starch. The degrees of degradation varies from product to product depending on the environment they’re designed to be disposed in, ranging from inside the human body to inside an industrial composter.

[SEE] If there’s anything that marks humanity’s brief time on Earth, it’s plastic

Such conditions, however, do not exist in the marine environment.

“Some common nonbiodegradable polymers, such as polyethylene, are sometimes manufactured with a metalbased additive that results in more rapid fragmentation (oxo-degradable). This will increase the rate of microplastic formation, but there is a lack of independent scientific evidence that biodegradation will occur any more rapidly than unmodified polyethylene. In a recent UNEP report it was concluded that the adoption of products labelled as ‘biodegradable’ or ‘oxo-degradable’ would not bring about a significant decrease either in the quantity of plastic entering the ocean or the risk of physical and chemical impacts on the marine environment, on the balance of current scientific evidence (UNEP 2015a). In addition, mixing of such plastics with normal plastics in the recycling stream may compromise the properties of the newly synthesised polymer22,” the authors wrote.

Around 300 million tonnes of plastic are manufactured each year. Only a fraction is recycled, the rest ending up in landfills, waterways and oceans. Plastics pose a great threat to marine life. The sight of suffering wildlife entangled and suffocating with plastic debris is a common reality. Microplastics — plastic particles smaller than five millimeters — are arguably the worse because these become easily ingested. This is why  toothpaste, cosmetics, cleansing agents and skin exfoliators which contain plastic microbeads were banned in California last year. Not only isn’t there any evidence that biodegradable plastics break down fast enough in the open ocean, where they sink and can’t reach the necessary temperature to decompose, but when they do break down they form these micro particles.

The authors of the U.N. report say that the only sustainable solution to managing plastic waste is to properly collect, dispose and recycle.

“There is a moral argument that we should not allow the ocean to become further polluted with plastic waste, and that marine littering should be considered a ‘common concern of humankind,’” the report says.

share Share

What Happens When You Throw a Paper Plane From Space? These Physicists Found Out

A simulated A4 paper plane takes a death dive from the ISS for science.

A New Vaccine Could Stop One of the Deadliest Forms of Breast Cancer Before It Starts

A phase 1 trial hints at a new era in cancer prevention

After 700 Years Underwater Divers Recovered 80-Ton Blocks from the Long-Lost Lighthouse of Alexandria

Divered recover 22 colossal blocks from one of the ancient world's greatest marvels.

Scientists Discover 9,000 Miles of Ancient Riverbeds on Mars. The Red Planet May Have Been Wet for Millions of Years

A new look at Mars makes you wonder just how wet it really was.

This Is Why Human Faces Look So Different From Neanderthals

Your face stops growing in a way that neanderthals' never did.

Ozempic Is Changing More Than Waistlines as Scientists Wise Up to Concerning Side Effects

But GLP-1 drugs also offer many benefits beyond weight loss.

Researchers stop Parkinson's symptoms in mice using a copper supplement. Could humans be next?

Could we stop Parkinson's by feeding neurons copper?

There's a massive, ancient river system under Antarctica's ice sheet

This has big implications for our climate models.

I Don’t Know Who Needs to Hear This, But It's Okay to Drink Coffee in the Summer

Finally, some good news.

New Blood Test Reveals How Fast Your Organs Are Aging. Your Brain’s Biological Age May Hold the Key to How Long You Live

People with "older" brains had a much higher risk of dying compared to "younger" brains.