Bioplastics: Not all Plastics are Created Equal

In No Impact Man, a book about living eco-effectively by Colin Beavan, the author refused to buy water in plastic bottles in order to save waste and minimize his use of a product (plastic) that is usually derived from fossil-fuel sources. And while his article on 42 Ways to Not Make Trash recently inspired me to buy a reusable shopping bag from Whole Foods, begin drinking coffee ‘in’ at my local coffee shop (not Starbucks) when I can, and use a Brita filter instead of buying water in plastic bottles, many of his tips seem extremely inconvenient and discouragingly hard to turn into ‘good habits’ for the rest of us.

But what if those plastic bottles of water, plastic bottles of Coca Cola and Ketchup we hold dear as Americans, those plastic smoothie containers and shampoo bottles, were bioplastics, plastics made from plant-based sources instead of fossil petrochemical sources? While we should still try to avoid the use of plastics whenever we can, and recycle whenever we can, could the use of bioplastics for staple food and other commercial products help the environment?

This question is not as simple as it might seem. It depends on many things, including the energy use that goes into these bioplastics, concerns about crop use and deforestation for bioplastics, and whether these ‘greener’ plastics are realistically recyclable, ideally able to be recycled along with traditional plastic materials [see Plastic-7]. While some bioplastics, including polylactic acid (PLA) materials often made from corn, have been controversial for their use of edible crop products and the difficulty of recycling these products with petrochemical plastics, bio-based forms of conventional plastics might be more cost-friendly and compatible with available recycling services.

As I’ve found out just looking into bioplastics, it seems to take a fair amount of awareness and care on the part of the consumer to know which bioplastics they should buy, which ones are recyclable in their local communities, and which ones are truly better for the environment. I have friends who have M.S. degrees in biological engineering who still get frustrated trying to determine which materials are recyclable and which go into which recycle bin at Whole Foods. Anything that makes it easier for consumers to recycle correctly is a win for the environment. Most people aren’t going to drive out of their way to a special recycling center for a bottle made out of some obscure bioplastic they they just got from a take-out restaurant.

There currently seems to be a focus on bio-derived versions of today’s existing petrochemical plastics, like polyethylene terephthalate (PET) in the form of bio-PET, and polyethylene (PE_ products from sugarcane ethanol, for example. Bio-based PE “is in the most advanced stage of commercialization,” but other commercial products include ‘green’ PET, PLA as an alternative to polystyrene, and even PVC from bio-based ethylene. According to an article in American Scientist: “The carbon released from these plastics represents no net addition to the atmosphere, whereas the production and incineration of petrochemical plastics boosts CO2 [carbon dioxide] levels.”

Coca Cola’s new PlantBottle is made from a bioplastic: “PlantBottles are made with a PET resin containing biobased monoethylene glycol (MEG). Currently, MEG is about 30 percent of the PET plastic; purified terephthalic acid, or PTA, makes up the remaining 70 percent. In the next few years, Coke hopes to conquer that 70 percent.” The real challenge seems to be getting consumers, if not to give up plastics altogether, to favor buying products sold in the PlantBottle and other recyclable bioplastics[1] over conventional plastics that are familiar and sometimes still cheaper. See other companies that are using plastics from sugarcane polyethylene.

Of course, bioplastics aren’t all good. They have downsides, and they are still plastics that can have negative effects of health and environment: they can cost more, they may come with agricultural industry practices of fertilizer and pesticide use, and they aren’t necessarily biodegradable or recyclable. But as long as consumers make smart choices for environmentally-friendly plastic bottles and packaging that they can recycle in their area, bioplastics could definitely be more sustainable that petrochemical-derived plastics.

According to an article published by Compounding World, a magazine for polymer compounders:

By 2015, the trade association [European Bioplastics] expects durable bioplastics – including bio-based commodities such as PE, PP, PET and PVC as well as high performance PA polymers – to account for close to 60% of its predicted global bioplastics production capacity of 1,700,000 tonnes. That translates to a more than 40-fold expansion in durable production capacity, from 22,500 tonnes in 2009 to 996,000 tonnes by 2015.

What do you think about bioplastics? Would you reach for one product instead of another, a Coca Cola product in a PlantBottle, for example, based on the environmentally-friendly packaging? Would you buy your new Ford Truck with bioplastic seats instead of conventional petrochemical plastic seats, even if it meant spending a bit more money?

Are you willing to give up certain plastics entirely?

[1] Valuing Bioplastics: Big companies find eco-friendly substances have Limited consumer appeal. Chemical & Engineering News.