Tag Archives: polymer chain

Are Bioplastics Really as Biodegradable as You Think?

Starch from corn is used to create PLA plastic.

When you hear the word “bioplastics,” you might imagine a bottle or container that easily breaks down into soil and other natural matter soon after it’s tossed — but that’s not necessarily the case.

Bioplastics are made with ingredients from renewable sources, such as potatoes and corn starch (also called PLA plastics), rather than petroleum or natural gas, and therefore, you would expect them to be biodegradable. Surprisingly, this is not always true, and there are many drawbacks to bioplastics you may not be aware of.

First, bioplastics can’t be recycled with traditional polyethylene terephthalate (PET) plastics because they contaminate the PET plastic stream. Wouldn’t it be terrible if all the plastic you’ve so diligently placed in your recycle bin for the past month winds up in a landfill because some “bioplastic” got mixed up in it? And sorting the different plastics is an option, but that takes time, accuracy and a hefty financial commitment. Second, landfill environments rarely provide a sufficient amount of heat, light and oxygen necessary for bioplastic breakdown, so bioplastics that end up there don’t decompose and instead last for hundreds, or possibly thousands, of years.

Bioplastics that are marketed as being “biodegradable” can cause a lot of confusion. The misunderstanding lies in the area between what the material is capable of (the extent and rate at which it biodegrades) and what specific conditions must be present in order for it to do so. For example, a corn starch-based plastic certainly has elements that will break down, but it needs the application of extremely high heat for this to occur, something that likely won’t be present in a landfill, nor in your compost heap in the backyard. These plastics will have to be accepted by one of the few commercial composting facilities, where all the decomposition conditions can be controlled, in order for them to successfully biodegrade.

Traditional PET and PLA bottles could last for thousands of years in a landfill.

Other drawbacks to bioplastics include abnormalities from a manufacturing and distributing standpoint. PLA plastics just don’t “behave” quite the same way that traditional plastics do. For example, bottles, utensils and other objects made of PLA plastic can only resist heat up to 110 degrees Fahrenheit (with certain resins, possibly up to 200 degrees) before their strength is compromised and they begin to melt. Additionally, bioplastics generally have weaker oxygen barriers and decreased impact resistance. All these factors can negatively impact shelf life, ease of distribution and contact with hot foods and liquids.

It would seem as though consumers have to choose either PLA plastics, which will melt, reduce product shelf life, contaminate recycling and last for centuries in a landfill, or traditional PET plastics, which work great but will last for just as long. So what do you do?

An effective solution to this problem must take the needs of manufacturers and distributors, as well as realistic landfill conditions and the processes of recycling facilities, into consideration. ENSO Bottles manufactures plastic bottles that have been specifically designed to meet those challenges. During the plastic’s creation, an additive is included which inserts organic compounds into the polymer. The result is a plastic with the same properties as traditional PET plastic (with regards to strength, heat resistance and the oxygen barrier) that can be recycled right along with PET plastic, but can also decompose in a typical anaerobic landfill environment. What’s the key? Microbes.

Check with the recycling facility to see what it does and does not accept.

With those organic compounds added into the molecular structure of the plastic, ENSO Bottles become very attractive food sources to the microbes present in landfills, and the plastic is “eaten away,” in a sense. As the microbes seek out the nutrients provided in the ENSO additive, they break down all parts of the polymer chain, including the plastic, into non-harmful bio-gases and bio-mass in a process that typically lasts between one and five years — a far shorter timeframe than the potentially hundreds or thousands of years it takes a traditional PET bottle to decompose.

So the next time you start to toss a bioplastic water bottle or packaging into a trash bin, consider where it’s probably headed: a landfill, where it will likely never experience the ideal conditions it requires to biodegrade. Contact your local collection facility instead to learn whether or not it accepts that category of plastic (referred to as #7), and better yet, consider your alternatives, such as the biodegradable ENSO Bottles.