Market At-a-Glance
The relentless growth of the multi-billion-dollar bioplastics industry, expanding at an impressive rate of 20-30% annually, aims to address the pressing challenges posed by the trillion-dollar global plastics market. Are bioplastics a silver bullet to combat the critical issues associated with petroleum-based plastics and food waste piling into landfills?
Outline
What are Bioplastics? Key Definitions
We hear these words sustainable, renewable, biodegradable being thrown around all the time, and we have to actually stop and think for a second about what these words actually mean, because it will help us draw important distinctions.
Plastics are made of polymers, or long, flexible chains of chemical compounds. Their properties allow them to be molded and shaped, especially under heat and pressure. Petroleum oil-based plastics come from the pressurized remains of plants and animals, so-called fossil fuels, and as a result they are technically considered organic matter.
On the other hand, we have biobased plastics, called bioplastics. These are made in part or completely from renewable biological sources such as carbohydrates, fatty acids, amino acids, bacteria, fungi, and algae. Some popular sources of raw materials (also known as feedstock) include corn, cotton, sugarcane, hemp, mycelium, algae, wool, silk, wood, nuts, fruit, coconut, food and human waste, milk, and used cooking oils.
Biodegradable has a stricter definition, which means the material breaks down into non-toxic natural products, like biomass (compost), inorganic products, carbon dioxide, and water. Bioplastics are not necessarily biodegradable. For example, PLA bioplastic does not biodegrade in the ocean. bio-PE, bio-PP, and bio-PET are naturally-sourced and thus renewable, but they are synthetic, chemically identical to fossil fuel-based plastics, and non-biodegradable. Whether made from petroleum or plants, plastics that have similar molecular composition will have similar properties and health implications. Persistent organic pollutants are attracted to petroleum plastics and the plasticizers or additives in the ocean (McGuire, 2018 - News Journal Online). Conversely, latex can still be used to make 100% all-natural latex gloves, tires, and mattresses, and they are biodegradable. Thus, we need to be more specific and discerning.
On the flipside, not everything biodegradable is a bioplastic. Biodegradable plastic can sometimes be made entirely from fossil fuels. Note that biodegradable things get compacted, preserved, and mummified in a landfill.
Overall, what we’re looking for on our checklist is a replacement for petroleum oil plastics in biodegradable bioplastics that minimize harm to people and the planet throughout their life cycle and in the end are handled appropriately at waste management facilities.
A Brief, Burgeoning History of Bioplastics
Ancient Roots
The industrial-scale commercialization of bioplastics really began only in the last 100 years. However, the roots of bioplastics reach as far back as 1500 BC, when indigenous Mesoamerican cultures such as the Olmecs of Mexico, Mayans, and Aztecs, used sap from gum and rubber trees. This natural resource was transformed into latex balls for games, containers, and even waterproof clothing. These ancient societies demonstrated an early understanding of the potential of bioplastics, harnessing the versatility of organic materials to create functional products that seamlessly integrated with their environment (National Geographic).
Seeds of Innovation
Fast forward to the 20th century, where the foundations of modern bioplastics were laid amidst scientific discoveries and industrial progress. In the 1920s, Wallace Corothers, the inventor of nylon, stumbled upon the precursor to bioplastics when he discovered polylactic acid (PLA). This milestone marked a significant step towards the development of biodegradable plastics.
The late 1920s also saw the pioneering efforts of Maurice Lemoigne, a French researcher who fed bacteria Bacillus megaterium sugars to produce polyhydroxybutyrate (PHB), one of the earliest forms of bioplastics. Lemoigne's work exemplified the idea that nature itself could serve as a manufacturing hub for sustainable materials (British Plastics Federation).
Finally, Henry Ford was the first to use bioplastics made from soybeans in the automotive sector in the 30s (Bioplastics News).
Post-World War II: A Plastic Revolution
However, during World War II, demand for bioplastics took a back seat, as synthetic plastics were mass-produced. The abundance of a cheap oil supply led to a surge in petroleum-based plastics for the ensuing decades, perpetuating a cycle of environmental consequences that would ultimately ignite the search for greener alternatives.
Navigating Embargos and Rising Oil Prices
Economic, political, and ecological factors converged in the 1970s to shift the spotlight back to bioplastics. The embargo of Arab oil-producing countries, combined with rising oil prices and a dependence on oil, created oil and energy crises and reignited interest in sustainable alternatives to petroleum-based plastics.
In 1975, a team of Japanese scientists discovered the principle of biodegradable plastics. They discovered that a bacteria, Flavobacterium, broke down nylon in wastewater from a nylon factory.
By 1979, the Iranian Revolution and Iran Iraq War caused expensive oil prices, huge debts, and deficits in Western nations. This led to overproduction and oversupply of oil in the 1980s, making it less urgent to find alternatives to oil-based plastics.
The 90s: Thriving Innovations
Newfound momentum spurred Novamont’s establishment in 1990, which played a pivotal role in advancing the bioplastics industry. In 1992, Chris Somerville from Michigan State University reported in the journal Science that bioplastics (PHB) could be produced from a plant called Arabidopsis thaliana. Joint ventures between corporations like Cargill and Dow Chemicals in the late 1990s paved the way to produce polylactic acid (PLA) from corn in 2001, creating a significant breakthrough in renewable bioplastics. Rebranded as NatureWorks in 2005, the company is the leading PLA producer.
21st Century Innovations: A Sustainable Future
As we navigate the challenges posed by single-use plastics and escalating waste, the bioplastics industry continues to evolve and innovate. Major corporations are beginning to embrace bioplastics as a sustainable solution, with the potential to transform entire industries. While bioplastics still face technical, financial, logistical, and societal acceptance hurdles, the historical journey of bioplastics serves as a testament to human ingenuity and our ability to create environmentally conscious alternatives.
In an era where environmental preservation is paramount, the legacy of ancient civilizations, combined with the scientific breakthroughs of the past century, converges to shape the promising future of bioplastics. As we look ahead, the lessons of history remind us that sustainable solutions are within our reach, awaiting further exploration and tinkering before they seamlessly integrate into our modern lives.
Petroleum-Based Plastics and Waste Management Problems
Environmental Harm from Oil and Gas Industries
Traditional plastic production predominantly relies on petroleum sources, involving processes like hydraulic fracturing (fracking) that exacerbate environmental woes. Fracking, the extraction of crude oil and natural gas, involves injecting water, chemicals, and sand into Earth, undoubtedly more environmentally intensive. Fracking causes air pollution, releases methane, contaminates groundwater, causes earthquakes, and disturbs land and ocean habitats (National Geographic).
Ocean Persistence
The oceans are inundated with plastic waste. About 60-80% of marine debris is made of plastic. A staggering 94% of ocean plastic is microplastic, and each year, 12.7 million tons of end up in the ocean.
Plastic and Food Waste
The lifespan of plastics contrasts starkly with the time taken to create them, leading to their accumulation in landfills. It takes 77 million years to make fossil fuels and 45 minutes to use them as a coffee cup. As a result of this disparity, 55% of all plastics produced since 1950 is currently in a landfill, according to Our World in Data, with single-use plastics constituting about 40% of all plastic waste.
Many environmental initiatives have attempted to chip away at the plastic crisis by focusing on single-use plastics, but food waste infrastructure further compounds the problem. According to the EPA, food waste makes up 22% of landfills by weight, followed by plastics at 19%. 1.3 billion tons of food is wasted or thrown out every year, according to the UN, accounting for 1/3 of the world's food production.
Some may find the irony in mummifying garbage, which is derived from fossil fuels. We can downsize these wasteful trash tombs with careful infrastructure planning, as half of waste in a landfill is biodegradable, like food and paper.
Health Concerns
Plastics have been found in an estimated 93% of Americans, according to the USDA. Much of our food is stored in plastic, to our detriment. Fats, acidity, or heating can cause plastic to leach into our food.
Petroleum-based plastics raise a multitude of health issues due to their chemical composition, which includes plasticizers like BPA, BPS, BPF, and phthalates. Plasticizers, added to make plastics stiffer or more flexible, may be endocrine-disrupting and estrogenic, affecting hormone regulation or metabolism.
Namely, these harmful plasticizers have been associated with infertility, cancer (breast, ovarian, prostate, and liver cancers), neurotoxicity, heart disease, metabolic syndrome, microbiome disruption, vitamin D depletion, inflammation, DNA damage, asthma, allergies, and ADHD.
Pollution Creates Socioeconomic and Public Health Disparities
Pollution disproportionately affects low-income communities, and property value in highly contaminated areas tend to be lower, underscoring the urgent need for sustainable alternatives to plastic.
Greenwashing Companies Mislead Consumers
From Oxford dictionary, “greenwashing” is defined as disinformation disseminated by an organization (through branding, mislabeling, packaging, or public relations campaigns), to present an environmentally responsible public image. It’s things like emphasizing recycling, even though that solution has proven paltry. If bottling companies such as Nestle and Coca-Cola continue to shirk social responsibility and blame consumers instead of taking accountability as manufacturers, nothing will change.
Unfortunately, companies also exploit regulations to commit greenwashing by using composite materials: according to Natracare, only 20-30% of the ingredients in the product need to be from renewable, organic materials in order for a plastic to be labelled ‘plant-based’. These could still be non-biodegradable and be made from up to 80% fossil fuels. For example, Green Dot Bioplastics uses 70% petroleum-based plastics (reclaimed polypropylene) composited with 30% organic materials like wood.
On a positive note, Keep America Beautiful (KAB) is a lobbying group that has released decades of greenwashing propaganda, sponsored by H&M, Clorox, Dow, Northrop Grumman, McDonald’s, Coca-Cola, PepsiCo, and Nestle, blaming the consumer for plastic production and preventing local governments from banning plastic bags.
The Rise of Biodegradable Bioplastics: A Path Forward
Market Growth and Potential
The burgeoning bioplastics industry offers a beacon of hope, as it grows exponentially to tackle the plastic problem head-on. With its impressive 20-30% annual growth rate, bioplastics have the potential to reshape the market and revolutionize plastic consumption (Columbia).
Learning from the Trillion-Dollar Industry
We can apply the properties of petroleum plastics that enabled their success to the nascent industry. Along that vein, bioplastics should be cheap and lightweight, enabling fuel-efficient transport. They should also be hygienic, preserving food and protecting against moisture and bacteria. In addition, they should have a long shelf-life, be durable and reliable, and provide increased water security in times of crisis. Finally, they should be easily heated, moldable into diverse shapes, and stable at room temperature.
Renewable and Compostable
Compostable bioplastics are renewable and produce harmless breakdown products when exposed to microorganisms or the right conditions. Biodegradable bioplastics break down in weeks to months when appropriately handled, as opposed to taking hundreds of years to decompose like many petroleum plastics.
Healthier for Humans and Planet: Less Resource-Intensive
Bioplastics require less water than fracking and result in fewer carcinogens, ecotoxicity, respiratory effects, and smog. They generate far less air pollution than petroleum-based plastic and are free of toxic, endocrine-disrupting chemicals like BPA.
Another advantage of biomass packaging is that it can be grown all over world, as opposed to oil, which is concentrated in regions. As a result, it supports a rural, agrarian society, which, compared with city life, is healthier for human microbiomes, lungs, and psychological well-being.
Diverse Applications
Biomass manufacturing can benefit numerous industries, including consumer care, writing materials, food packaging, entertainment, textiles, agriculture, medical devices, construction, and biofuels.
Around the home, biomaterials can be used for toothbrushes, makeup, exfoliating washes, pens, adhesives, plant-based inks, gift cards, toys, yoga mats, speakers, and even glitter: Blue Sun’s Cosmetic Bio-glitter uses eucalyptus to create biodegradable glitter [1].
Biomedically, biomaterials can be used for medical devices, such as invisible aligners, absorbable surgical sutures, slings, prostheses, medical implants, bone plates, skin substitutes, scaffolds for growing tissues or organs for transplant, and tissue engineering. Medicine can benefit from biomaterials, including using biopolymers for controlled drug release, drug packaging, drug discovery.
Food packaging, mulch films, and fish nets made of bioplastics can cut down on agricultural waste and ocean pollution. Biobased car insulation and car headlights can advance the transportation industry. Finally, within construction, tiles, planters, bricks, garden furniture, paints, and biochemicals can be made from biomaterials.
All things considered, bioplastics are most practical for single-use items, household and personal care items, food packaging and agriculture, and clothing.
Supply Chain Ingenuity: Closed-Loop and Double Revenue Business Models
Biomaterials create many options for smart supply chain solutions and closed-loop business models. For instance, bio-based and food waste can be diverted from landfills and recycled into plastic. Rather than using de-novo feedstock, we can preserve crop growth and not offset agricultural production used to make food. This presents an opportunity for a double revenue stream—companies can be paid to collect waste and then paid again when people buy their products out of those materials.
Challenges and Considerations
Bioplastics come with unique technical challenges, such as differing chemical properties, lack of infrastructure, and high upfront costs. Some of the primary concerns are highlighted below.
Food-Derived Feedstock’s Environmental Impact
Bioplastics, while promising, are not without their challenges, in line with agriculture and aquaculture. Making bioplastics requires land and aquatic resources. Food-derived feedstock could divert land away from food production and contribute to intensive agricultural practices. For instance, take corn-based bioplastics like PLA. Cultivation of corn uses more nitrogen fertilizer, more pesticides, herbicides and more insecticides than any other U.S. crop; those practices contribute to soil erosion and water pollution when nitrogen runs off fields into streams and rivers (Smithsonian).
Waste Management Infrastructure: Logistical Difficulties
Many bioplastics rank high in green design but average in life cycle assessment (LCA) [2]. A major problem starts when we’re done using these products and they’re discarded. For starters, biodegradable bioplastics must be diverted from landfills and taken to industrial composting facilities that use 60-degree Celsius (140-degree Fahrenheit) heat and oxygen to break down plastics. A lot of times, they're visually indistinguishable from plastics, so many composting facilities may not accept them in the first place.
The proposed solution is simple and would keep organic waste out of landfills: create a third waste stream in households for biodegradable compost, and build more industrial composting facilities in the US. An alternative solution is to manufacture biomaterials that can biodegrade in a home composting environment. A composting revolution would separate stream for compost, recycling, and trash.
But wait, there’s another problem: even in compost, the chemistry of bioplastics gets dicey. The breakdown product’s pH (e.g. lactic acid is acidic) and consistency (liquid makes compost wet) matters. That can affect the quality of compost.
Biomaterials can also release greenhouse gases, such as methane. A solution is to use an anaerobic digester and capture the methane for fuel. This points to the need for biorefinery and green waste management infrastructure.
Shelf Life and Barrier Integrity
Bioplastics have different chemical properties and need to undergo testing. These products often don't offer a sufficient barrier against water vapor, oxygen, or flavors, and they may have an off-flavor. In that case, carbonation may escape, and the shelf life could be lower.
Bioplastics that are, by design, meant to biodegrade, may have low chemical stability, short-term effectiveness, and low solubility. A lower melting point of bioplastics raises questions: will they leach into food? Will they disintegrate in storage? PLA can't exceed 114 degrees—in that case, a takeout container can melt into a pancake in your car.
However, these concerns are resolvable. Often, combinations of proteins and polysaccharides yield better results as wall materials than single polymers. That said, the characteristics and interactions of the ingredients are highly variable and should be optimized before any industrial application [3].
Manufacturing Impurities
Chemical processing is needed to turn organic material into plastic—that means green solvents need to be considered. Using acid catalysts to transform glucose and fructose (from cellulose, starch) into a basic building block for plastics also yields a vat of impurities, such as levulinic and formic acids and hydroxymethylfurfural (HMF) (Scientific American).
Genetically-Modified Organisms (GMOs) and Environmental Hazards
Some bioplastics are genetically modified, especially corn-derived PLA. It's been argued that metabolic and genetic engineering of microbes and plants can improve yields, while reducing costs, but this remains controversial.
According to data presented by Okano and colleagues, Lactobacillus plantarum yields and purity of I-lactic acid (I-LA) decreased after genetic engineering, though they drew different conclusions [4]. Thus, GMOs could also lower yields. Environmentalists are also concerned GMOs will disrupt the local ecosystem and contaminate crops.
Food Allergies and Intolerances
Some bioplastics may carry health risks, requiring careful consideration. Naturally-derived biomaterials raise the issue of dietary preferences or allergies. People might not want to eat something that contacted fungi or bacteria, or they may have allergies or food sensitivities. Thus, proper labeling regulations are important in the bioplastics industry.
Degradation Profiles and Pathogenic Biofilms
How exactly these products degrade in nature remains unknown. PLA and starch-based bioplastics formed pathogenic Enterococcus faecalis biofilms similar to those formed on polyethylene in artificial marine conditions, highlighting public health concerns [5]. As a result, many operational industrial composting facilities today won’t even accept PLA and other biodegradable plastics—they are seen as contamination risks (Packaging Digest).
Foit and colleagues propose analytical methods for determining levels of micro-bioplastics of PLA, PHB, and PBAT [6]. The technology exists to test degradation profiles, so the search is on for safely-degrading biomaterials.
A Copout for Single-Use Packaging?
Customers like convenience, but they also like to think they're doing good. Critics say PLA legitimizes single-serving, over-packaged products. It will be much more difficult to adopt these changes in an absence of evidence that they do less harm to the environment than existing materials. The good news is that they are generally safer than petroleum plastics; however, whether they generate less waste is up for debate.
Cost and Scalability
Biomaterials come with high upfront costs and issues with scalability. Major corporations can afford to absorb the cost, but convincing them to adopt these alternatives remains challenging. Getting big food and beverage companies on board will really alter the equation—Nestle alone produces 1.7 million tons of plastic packaging a year, enough to make 51 billion bottles. Beverage makers like Coca-Cola Co. and PepsiCo use a lot more than that (Quinn, 2019 - Bloomberg). Early adopters and innovators / disruptors may move faster than unwieldy, bureaucratic corporations, keeping their eyes on a viable long-term strategy.
Future Directions
As we navigate the complexities of transitioning to bioplastics, it's crucial to acknowledge both their potential and their limitations. Compostable bioplastics offer a promising avenue towards reducing our reliance on petroleum-based plastics and mitigating the environmental impact of non-renewable, resource-intensive processes. All-in-all, bioplastics are poised to solve two problems at once, potentially shrinking landfills by up to half and fostering composting practices.
However, a comprehensive approach is needed, involving advancements in technology, waste management infrastructure, and a collective commitment to the Earth. All-in-all, many investments, efforts, and advancements are being made on the scientific and engineering front to move us closer to a circular economy.
References
Melilli, G., et al., DLP 3D Printing Meets Lignocellulosic Biopolymers: Carboxymethyl Cellulose Inks for 3D Biocompatible Hydrogels. Polymers (Basel), 2020. 12(8).
Tabone, M.D., et al., Sustainability metrics: life cycle assessment and green design in polymers. Environ Sci Technol, 2010. 44(21): p. 8264-9.
Hosseini, H. and S.M. Jafari, Introducing nano/microencapsulated bioactive ingredients for extending the shelf-life of food products. Adv Colloid Interface Sci, 2020. 282: p. 102210.
Okano, K., et al., Metabolic Engineering of Lactobacillus plantarum for Direct l-Lactic Acid Production From Raw Corn Starch. Biotechnol J, 2018. 13(5): p. e1700517.
Hchaichi, I., et al., Enterococcus faecalis and Vibrio harveyicolonize low-density polyethylene and biodegradable plastics under marine conditions. FEMS Microbiol Lett, 2020. 367(15).
Fojt, J., et al., A critical review of the overlooked challenge of determining micro-bioplastics in soil. Sci Total Environ, 2020. 745: p. 140975.