What Are Bioplastics? Overview and Impacts

Bioplastics can be sustainable, but standards need to be established.

• Wesleyan University, University of California, Berkeley

David Kuchta, Ph.D. has 10 years of experience in gardening and has read widely in environmental history and the energy transition. An environmental activist since the 1970s, he is also a historian, author, gardener, and educator.

• Planet Earth
• Climate Crisis
• Pollution
• Recycling & Waste
• Natural Disasters
• Transportation

Bioplastics are plastics made from renewable biological material, usually plants, waste, or microorganisms rather than petroleum or natural gas. Many bioplastics can be far more beneficial to the environment than plastics made from fossil fuels, but others can be no better than the original. It depends on how bioplastics are made.

The bioplastics industry is young; in 2019, bioplastics represented only 1% of the world’s plastic production. There is currently little standardization for sourcing raw materials, types of plastics, or labeling what is biodegradable or compostable. This makes it difficult for consumers to judge whether they are doing anything environmentally beneficial by choosing bioplastics over fossil-based ones.

Yet growing awareness of the toxicity of plastics and increasing government regulation of plastic waste has led to a surge of interest and investment in bioplastics—an industry that is expected to grow by 10% to 14% from 2020 to 2025. This growth has the potential to help solve one of the world’s worst environmental problems: plastic pollution.

The Threat of Plastic Pollution

Marine plastic pollution is a growing global environmental crisis, represented most visibly by the Great Pacific Garbage Patch. Of the approximately 36 million tons of plastic produced in the U.S. every year, less than 1% gets recycled, according to the EPA. Only roughly 9% is recycled worldwide.

Every year, about 11 million tons of plastic waste are dumped into the world’s oceans. Even more comes from terrestrial sources, where plastic slowly breaks down into smaller and smaller particles called microplastics. Up to 51 trillion microplastic particles float in our oceans. The average adult human ingests an estimated 883 particles of microplastic each day—an irreversible intake that accumulates in body tissue. When ingested by marine and terrestrial organisms, they can have adverse health effects, from immune responses and toxic contamination to malnutrition and starvation.

How Is Bioplastic Made?

To produce bioplastic, polymers (complex chains of molecules) are extracted from biomass to be formed into plastic products. That biomass can include corn, sugarcane, vegetable oils, and other edible sources called first-generation biomass. Producing bioplastic from first-generation biomass on land that could otherwise be used to grow food is controversial, as it can compromise food security.

So-called second-generation biomass includes wastes from agriculture, industry, cooking, food, foresting, and municipal landfills. Since it is not edible, its production doesn’t take the place of food production. Third-generation largely refers to seaweed, cyanobacteria, and microalgae. The latter can be cultivated in wastewater, including municipal water treatment facilities, meaning its cultivation doesn’t threaten other land uses.

Bioplastic polymers can also be made from reused or recycled bioplastics, making them part of a circular economy.

What Is the Carbon Footprint of Bioplastics?

Fossil fuel-based plastics contribute 3.4% of the world’s annual greenhouse gas (GHG) emissions. Nearly two-thirds (63%) of those emissions come from the production of crude oil and its refining and conversion into polymers, even before those polymers even reach the plastics factory. Another 22% of emissions come from turning polymers into products, while waste management adds another 15%, due to the fact that most plastics are incinerated rather than recycled.

Eliminating the use of petroleum in the production of plastics would go a long way to reducing the industry’s carbon footprint, but only if bioplastics were not produced from first-generation sources like corn or sugarcane, for which there would only be a roughly 25% reduction in GHG emissions. Switching the production process to rely on renewable, carbon-free energy for electricity and transportation would have a much greater effect than switching from fossil polymers to biomass polymers, as clean energy sources would reduce plastic’s carbon footprint by 62%.

Unlike fossil plastics, bioplastics can much more easily be part of a circular economy, as sources derived from wastes are carbon-neutral, giving second-generation bioplastics the “lowest global warming impact overall.” Third-generation bioplastics are less studied, as most have yet to reach commercial viability, but they hold great promise to reduce carbon emissions even further. Cyanobacteria and algae remove more CO₂ from the atmosphere than they produce as biomass, meaning their use as feedstocks for bioplastics is carbon-negative.

How "Bio" Are Bioplastics?

One of the key obstacles to the wider use of bioplastics is consumer confusion about their content and disposal. Even a life-cycle analysis of the different types of bioplastics led researchers to conclude that “it was not possible to conclusively declare any polymer type as having the least environmental impact in any category.”

Depending on its molecular structure, bioplastic may or may not be biodegradable: roughly 60% isn't. This confusion has led to criticism of bioplastics from environmental groups, bans in cities like San Francisco, and low adoption rates due to a lack of options for their disposal.

Some of the confusion and criticism stem from the fact that the terms “bioplastic” and “biodegradable” can mean many different things. Listed in order of least sustainable to most, products labeled “bioplastic” can be any of the following:

• petroleum-based but biodegradable,
• made from plants and renewable sources but not biodegradable,
• biodegradable but made from renewable first-generation sources such as edible crops
• biodegradable and made from second- or third-generation sources such as wastes or microalgae.

With no clear definitions, consumers are not only confused but they may also be convinced that the products they are buying are better than they actually are. Clarity in definitions, such as those of the European Union’s Product Environmental Footprint standards, is a step in the right direction toward greater bioplastic adoption and less greenwashing.

In 2020, the European Union’s Circular Economy Action Plan called for better labeling of bio-based plastics to clarify that their bio-based feedstock truly resulted in environmental benefits beyond just replacing fossil resources, and where “biodegradable” and “compostable” meant degradable within a 12-week time frame rather than over decades or centuries.

The Future of Bioplastics

The development of fossil-based plastics has had tremendous consequences on the health of humans, animals, and the planet. Bioplastics can be part of a carbon-negative circular economy and help clean up what has become one of our worst environmental nightmares. To do so, a number of steps need to be taken:

• Standardize product labeling systems to automatically identify biodegradable bioplastics and to prevent misleading labeling of fossil-based plastics as “bioplastics.”
• Increase the availability of industrial composting facilities.
• Create single-sort recycling facilities to divert compostable bioplastics to a composting process.
• Raise consumer awareness of types of bioplastics.
• Shift production from non-biodegradable plastics to biodegradable ones.
• Implement regulatory protections to make sure that bioplastic feedstocks don’t compromise food security.
• Include financial incentives and regulatory penalties to encourage the commercial attractiveness of biodegradable bioplastics.

All compostable bioplastics biodegrade, but not all biodegradable bioplastics are compostable. Biodegradable just means they break down over time into their component elements.

Most likely not. Biodegradable bioplastics need temperatures of 60 degrees C (140 degrees F) for at least four days in order for them to properly decompose. Bring your bioplastics to an industrial composting site.

Some bioplastics—those with properties exactly the same as fossil plastic, such as BioPE—can be recycled.