When the San Francisco sea lion named Blonde Bomber made one of his regular appearances at the city's Pier 39, residents were alarmed at the plastic strap wrapped around his neck. Alarmed, but also not surprised: Plastic pollution is so ubiquitous in the ocean that there are activists who devote hours each week to saving wildlife from such debris. Fortunately for Blonde Bomber, a local organization known as The Marine Mammal Center was ultimately able to rescue him. The vast majority of ocean wildlife is not so lucky when it encounters plastic pollution.
The problem with plastic pollution, as the continent-sized Great Pacific Garbage Patch indicates, is that the type of plastic better known as "synthetic polymers" never biodegrades. Of course, that's part of the appeal. But now plastics are everywhere and too much of a useful thing is causing toxic problems on a global scale. These dangerous plastics include polyethylene, the most widely used plastic in the world (look for it in clear food wrap, shopping bags and automobile fuel tanks); polylactic acid (PLA), which is used in food packaging, clothing fibers and medical implants (it can be biodegradable, but not in all contexts); polystyrene, which is used in foam packaging peanuts, egg cartons and electrical insulators; and polypropylene, which can be used in making upholstery, carpets and ropes.
Plastic is incredibly durable and versatile, but it does slowly break down, producing smaller microplastics, which are now literally everywhere on Earth. Anywhere humans have searched for them, whether in clouds or at the bottom of the ocean, they've been found. They've also entered our bodies thanks to the foods we eat, the water we drink and the air we breathe; it is unclear whether these chemicals are hazardous, and if so to what extent.
Nonetheless, plastic pollution has been linked to infertility, and therefore could present a serious existential crisis for humanity in its future. It is also linked to cancer and, in microscopic form, plastic is even present in human blood and breast milk.
As such, there is an urgent need for biodegradable alternatives to plastics, particularly if they are biologically-based and safer if consumed by humans. The good news is these materials already exist. The question is why haven't they replaced most mainstream plastics, especially for so-called single-use packaging?
Part of the problem stems with defining what a "bioplastic" even is.
"There is no real clear definition of the term," Dr. Frederik Wurm, a professor for polymer chemistry at the University of Twente in the Netherlands and one of the world's foremost experts on bioplastics, told Salon. "What most people mean with 'bioplastics' can either be bio-based plastic — so meaning either fully bio-based or partly bio-based, meaning biomaterials [like seaweed] that are chemically modified — or they can be synthetic but biodegradable. They can also be fully bio-based, but not biodegradable."
For example, there is bio-polyethylene. Although it is like normal polyethylene, its monomer comes from ethanol instead of fossil fuels like petroleum and natural gas. Or there is lignin, a material produced in trees similar to the cellulose that makes up wood. Roughly 30% of a tree is actually lignin, which makes wood both hard and brown. Although it is usually burned away when paper is produced, since consumers often prefer white paper, it has unique qualities such as being biodegradable (with the help of certain fungi) and remaining stable when exposed to water.
"It also is brown, so it limits its application, and you can't use it for transparent things, so that might be a drawback. But the brown color also has benefits," Wurm said. Presumably, these limitations are workable and even replacing some plastics with biodegradable versions could be significant. So why aren't these alternatives flooding the market? The answer, according to Alix Grabowski, the senior director of plastic and materials science at the World Wildlife Fund, mainly comes down to one thing: Money.
"Biobased plastics are significantly more expensive than fossil-based plastics," Grabowski pointed out. "This has to do with both the incentives that exist for fossil fuels, which keeps them artificially cheaper, and the cost associated with the start-up of these new, complex supply chains. The playing field needs to be leveled with similar incentives or other cost-leveling solutions order for biobased plastic to be scaled." She also observed that it takes more time to establish supply chains for biobased feedstocks than for petroleum-based plastics, since the former are made by a different type of raw material and are sensitive to many external forces.
"Realizing the potential benefits of biobased materials requires attention to responsible sourcing, which requires due diligence and transparency — steps that are not generally taken with fossil-based plastic," Grabowski said.
Dr. Marcus Eriksen, the lead researcher at the 5 Gyres Institute, a non-profit organization that focuses on reducing plastic pollution, said that there are other factors which work against bioplastics in the marketplace.
"We know that conventional fossil fuel-based plastics are subsidized by taxpayers footing the bill for waste management," Eriksen told Salon. "Plastic producers, product and packaging manufacturers rely on cities to pay for cleanup of roadsides, beaches, rivers, pulling bags out of trees and off fences — and they pay for waste collection, recycling programs and landfills. Companies that make biodegradable materials are absorbing those externalities in the upstream cost of their production. It's hard for a bioplastics company to meet the price point of conventional plastics."
As a result, Eriksen advocates for extended producer responsibility (EPR) legislation in which "producers pitch in for End-Of-Life waste management, which levels the playing field."
Of course, this does not mean that there aren't hazards with involved certain bioplastics. "Some bioplastic materials have challenges with maintaining their properties over time, under UV light and [in] humid environments," Eriksen pointed out. "For example, in hot climates PLA can warp. The holy grail is a bioplastic that meets consumer needs, but decomposes when lost to the environment. Some materials, like biodegradable films for food packaging made from PHA or PHB, would be a good replacement material. Again, we need EPR to make sure everyone is contributing to waste management either by design or paying a fee."
Grabowski also observed that there can be ecological costs to bioplastics.
"Responsible production of renewable materials is an important piece of the circular economy," Grabowski told Salon. "However, agriculture has serious impacts on our planet and biobased plastics today are largely made from agricultural commodities. Their production can have complex effects on landscapes. Responsible sourcing ensures that biomass is grown, processed and delivered in a way that protects our natural resources so that we can continue to depend upon them in the future."
Additionally, when bioplastics are responsibly sourced, Grabowski said, it "protects the future ability of the agricultural system to operate successfully and builds resilience against climate change, supply shocks, and price volatility. Responsible sourcing depends on the feedstock used, local conditions, and the technology and process of production."
Yet for all of the challenges posed by bioplastics, economic and environmental alike, there is little question that a sustainable economy rests on alternatives to the environment-destroying standard.
"Ninety-nine percent of new plastics are made from fossil fuels," Grabowski observed. "This means, from the moment plastics are made, they are contributing to climate change and habitat degradation."
