Bothered and bewildered over bioplastics

By: 
November 19, 2015


It seems that there's much confusion over bioplastics. There are biodegradable plastics, landfill-degradable plastics, oxobiodegradable plastics (that degrade in the open environment), compostable plastics that require composting in a commercial composting facility with the proper microbial action and temperatures. . . . Meanwhile, accusations of greenwashing proliferate, as various bioplastic producers duke it out over whose bioplastic is greener, further complicating the issue.

Stuart Miles
Image courtesy Stuart Miles/
freedigitalphotos.net.

Both PlasticsToday's European reporter Karen Laird and myself have written about ECM Biofilms and that company's unsubstantiated environmental claims about its products: An additive that would promote degradation of plastics "in a landfill within nine months." I'm not so sure I'd be touting that my material will degrade in a landfill in nine months. That's as long as it takes a human woman to develop and have a baby!

I also have to ask, why do you even want to spend the money to purchase an additive to make plastic degrade in a landfill, when that plastic could be incinerated and the BTUs captured for energy? Or perhaps recycled into new products? I can't even fathom why a company would spend time and money to develop an additive that would cause plastics to degrade in a landfill, when a landfill is the absolute last place on the planet that we should put plastic!

Professor Emeritus Igor Catic of the University of Zagreb, Croatia, has pointed out to me in several papers he has written that all plastics are bioplastics because all plastics are derived from natural substances (petroleum and natural gas, which come out of the earth) and are combined with various chemicals in an industrial process to produce the type of plastic resin desired. Even the misleadingly named bioplastics need to be industrially processed with chemicals to cause the molecular chains to form and create a material with the properties needed in order to be injection molded, blowmolded, extruded or otherwise processed industrially to make products.

Catic notes that one of the first bio materials was galalith, based on casein (the main protein in milk), a process that is "more than six centuries old," said Catic. [A new report, "Milk Casein and Caseinates Market," notes that milk casein and caseinates perform multiple functions and act as emulsifiers, binders, viscosity enhancers and heat stabilizers. They have a wide range of applications in food and non-food industries, which makes it easy to see why casein would be used in the making of plastic.] Another popular product from the 19th century is celluloid made from cellulose nitrate, alcohol, fillers and pigments.

Globally, in 2014 more than 99% of plastics used were fossil-fuel derived plastics, with bioplastics representing only 0.2% of global production, according to data Catic obtained from PlasticsEurope. He pointed out that plastics should not even be termed synthetic because all plastics are bioplastics, as the "raw materials, such as oil, natural gas or coal" are biologically based, "the pure products of nature." For example, writes Catic, one of the first fossil fuel-derived plastics was "phenol-formaldehyde. "Phenol was first extracted from coal tar, but today is produced on a large scale (about 7 billion kg/year) from petroleum. It is an important industrial commodity as a precursor to many materials and useful compounds. Its major uses involve its conversion to plastics or related materials. Phenol and its chemical derivatives are key for building not only phenol-formaldehyde but also for some other plastics like polycarbonates, epoxies and nylon. So I propose to make the following classification: Plastic is a common name for all plastics, both those from fossil fuels and bioplastics."

Bioplastics has been, and will continue to be, a niche market. As Catic pointed out in a recent essay: "It is difficult to calculate how many scientific, professional and other efforts have been invested worldwide in proving the danger of plastic bags and the need to ban them." Not to mention the money spent to develop an industrial product that promises to disappear in nine months. There are many ideas out there of how to make plastic from various and sundry "natural" products such as corn, sugar cane and other plant materials, algae and palm oil, but these are also controversial when it comes to the total carbon footprint of growing, fertilizing, harvesting, processing and chemically producing something that is touted as bio, when oil and natural gas are also bio products.

Making blanket claims about bioplastics is tough to do, because as one person noted in an e-mail to me, ". . . claims are misleading as they are not qualified. We have never supported using general biodegradation claims for anything. If a product is landfill biodegradable, industrial compostable, marine degradable, home compostable, etc., the claims on the packaging should say so and provide the rate and extent [of that degradation]. To just say something is biodegradable or compostable is misleading, because there are so many different types of environments where both of those can and do happen."

But, I'm afraid the genie is out of the bottle. There are a number of large companies that have already spent millions—if not billions—of dollars developing these niche products and selling the "green" aspects. They must go forward with the "green" promotion or risk the demise of their companies. They can't turn back now without risking huge losses. A recent market study projected that the biodegradable plastics market alone will be worth $3.4 billion by 2020. While that is comparatively small in the overall resin marketplace, it's enough to make people who are vested in these products hang on for the long term, despite the lack of empirical or scientific evidence that one type of plastic is truly "greener" than another.

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