Top 6 Compostable Packaging Myths

I found my first compostable food packaging when shopping at a green grocery store in Baltimore back in 2010. I was excited, but skeptical so we took it home to put this packaging to test.

Fortunately I had a composter in my vegetable garden and already had a system in place, so I thought great no problem. I casually tossed it in my compost and watched over the next weeks and months as bugs took over my vegetable and fruit waste, but had little interest in my discarded container. Sadly, the container never broke down (at least over the period of a year). That’s because many compostable containers have to go to a high temperature composting facility to break down.

Compostable packaging has emerged as a potential hero in the battle against plastic pollution, promising a greener future for our waste disposal practices. But before we wholeheartedly embrace this seemingly eco-friendly solution, let's delve deeper and unveil the myths surrounding compostable packaging, explore its limitations, and discover better alternatives for a truly sustainable future.

Myth #1: Composting All Packaging is the Golden Ticket

In response to the plastic waste crisis countries all round the world have set targets to make plastic packaging 100% recyclable, reusable, or compostable, and to eliminate all unnecessary single-use packaging by 2025.

Not all packaging labeled "compostable" is created equal. While some truly decompose in industrial composting facilities, others require specific conditions like high temperatures and specialized composting systems not readily available in most homes or municipalities. Compostable and biodegradable plastics are currently incompatible with most anaerobic digestion (AD) systems and recycling systems.

Leaving such packaging in backyard compost bins or sending it to landfills can lead to incomplete breakdown, methane emissions, and even microplastic contamination.

Sixty percent of plastics that are certified for home composting don’t fully disintegrate, according to a study published in the journal Frontiers in Sustainability - an outcome of the Big Compost Experiment that recruited nearly 10,000 households to put compostable materials to the test in their compost containers.

Myth #2: Composting Packaging Solves the Plastic Problem

Currently, bioplastics represent less than 1% of the global plastic market. Production capacity is expected to grow from 2.2 million metric tons today to 7.4 million metric tons by 2028.

They are made using the same processes as traditional plastics. That means they contain many chemical additives; yet, even less is known about the potential toxicity of those chemicals than the ones in conventional plastics. Compostable packaging addresses plastic pollution only at the end-of-life stage.

This doesn't address the environmental impact of its production, which often involves resource extraction, energy consumption, and greenhouse gas emissions similar to traditional plastic. Additionally, compostable packaging production can still contribute to deforestation and water pollution.

Other studies show that bioplastics marketed as biodegradable can become persistent once they move into water, especially marine environments. Polylactic acid (PLA) in particular was found to linger in the marine environment for over 400 days. Natural and regenerated cellulose fibers in contrast were no longer visible after 35 days.

A study by 5 Gyres similarly found that products labeled biodegradable did not break apart in the environment. The researchers placed 22 bioplastics products — including film, utensils, straws, compostable bags, and baby wipes — in marine and terrestrial environments in three different states. This study also highlighted that thickness matters, with thinner materials fragmenting more easily.

Emerging newer-generation bioplastics made from feedstocks like food waste, algae, and mushrooms, however, show promise for having both lower carbon footprints than traditional plastics and fewer negative consequences.

Myth #3: Compostables can be Disposed of Anywhere

As their name implies, compostable materials need to be placed in a home or industrial composter. Composting conditions – defined by criteria such as temperature and humidity – enable these materials to disintegrate and biodegrade into soil.  

But, in 2019, other researchers at the University of Plymouth in the U.K. found that a number of compostable and biodegradable shopping bags failed to break down fully after three years in the natural environment.

According to waste charity WRAP, industrial composting conditions require a high temperature of 55-60°C, combined with a similar level of humidity and oxygen. Many composters don’t want to process compostable food packaging because they are concerned that chemical contamination and incomplete biodegradation will negatively impact the quality of their compost, as well as their bottom lines.

A recent field study by the Composting Consortium found that eight of nine composters studied had no detectable amounts of compostable packaging in their finished compost, but the study did not look at microplastics, which could well remain.

A review of dozens of research projects by the University of Vermont found widespread microplastic contamination in compost materials, though traditional plastic particles were more predominant than biodegradable plastic particles.

In one study, researchers found that compost containing biodegradable food packaging contained PFAS levels up to 20 times higher than compost made from manure or from separated food waste mixed with grass clippings and livestock bedding.

While home composting is growing in popularity, it requires specific knowledge, dedicated space, and ongoing maintenance. Access to industrial composting facilities is also limited in many regions, making widespread adoption of compostable packaging a challenge.

In the absence of collection systems to bring compost-friendly materials to a high-temperature industrial facility, these products have been found to more likely be landfilled or incinerated alongside conventional plastics. This creates more pollution and greenhouse gas emissions.

Myth #4: Compostable Equals Biodegradeable

Bioplastic products marketed as “plant-based,” “eco-friendly,” “biodegradable,” and “compostable” are becoming popular in the food industry with rising public awareness about the problems with single-use plastic packaging and plastic pollution.

With no federal standards defining or regulating bioplastics, companies have free rein to label whatever they want as “biodegradable” and “compostable.”

Commonly marketed bio-based compostable plastics include polylactic acid (PLA), polyhydroxyalkanoate (PHA), with the most prevalent being polyhydroxybutyrate (PHB), and polybutylenesuccinate (PBS), starch blends, and cellulose blends. Common fossil-based compostable plastics include polybutylenadipatterephthalat (PBAT) and polycaprolactone (PCL).

Many materials are biodegradable such as paper, cardboard, wood, and certain types of plastic. The word biodegradable does not describe under what conditions and how long a plastic will take to biodegrade.

Biodegradable plastic refers to a product that can break apart by natural processes in the environment, but without a specific timeline. Depending on the product, it can take days or weeks to centuries, depending on the material and the environment.

In contrast, compostable plastic refers to a product’s ability to be broken apart by microbes under controlled conditions (for oxygen, temperature, and moisture) at a commercial compost facility.

The term “compostable plastic” is more specific, it describes a material that is capable of undergoing biological degradation in a compost site at a rate consistent with other known compostable materials, leaving no visibly distinguishable or toxic residues. Certified compostable bioplastics are engineered to fully decompose within 12 weeks in a commercial composting facility.

Myth 5: Compostable Certification is Unbiased

Most states do not require products to be certified, which leads to rampant greenwashing. Manufacturers are free to label products as biodegradable or compostable without meeting any standards.

U.S. manufacturers can elect to follow voluntary industry standards developed by the American Standards Testing Material (ASTM), but not all do. Moreover, the fact that certification programs in the United States, Europe, Australia, and New Zealand are run by trade associations or advocacy organizations that represent bioplastics manufacturers, creates significant conflicts of interest.

For example, the board of the U.S.’s lead certifier of compostable packaging, the Biodegradable Products Institute (BPI), includes executives from some of the country’s most powerful petrochemical companies, including BASF, Eastman Chemical Company, TotalEnergies Corbion, and Danimer Scientific. Companies certifying their products through BPI also pay an annual membership fee that gives them a voice on the organization’s standards and procedures committee, a technical committee overseeing the validation process for BPI’s certification mark.

BPI does not do the actual testing of products. It requires manufacturers to use an independent lab that it has approved. To date, BPI has approved 33 labs that are a mix of private companies and university research units that are accredited by ASTM. Testing takes up to six months for both degradation and compostability.

The Center for Environmental Health and Clean Production Action have developed an independent, third-party chemical screening and certification program for single-use foodware products. The GreenScreen Certified Standard prohibits more than 2,000 chemicals of concern, including endocrine-disrupting chemicals like bisphenols, phthalates, parabens, and organotin compounds, and chemical classes like PFAS. Thus far, only two manufacturers, Eco-Products Inc., and NatureWorks LLC, have certified their products or raw materials through the GreenScreen Standard

Myth 6: Compostable Items are Cheaper

“Compostable” foodware is typically more expensive than conventional foodware. Biodegradable plastics generally cost 20-30% more than traditional plastics, primarily due to the use of natural raw materials and complex production processes. Costs vary widely by vendor but can range anywhere from double to six times the price of conventional plastics. For example, a 16-ounce PET or polypropylene cup can cost between $45 to $94 per 1,000, whereas “compostable” PLA cups can cost up to $190 per 1,000.

Packaging made from plant-based materials like cornstarch, sugarcane, seaweed, and mushrooms is generally less expensive than packaging made from more complex biodegradable materials like cellulose or PLA.

Beyond the Myths: Charting a Sustainable Packaging Path

Instead of relying on compostable packaging as a silver bullet, let's embrace these solutions:

Reduce, Reuse, Refill

Prioritize buying products with minimal packaging, opt for reusable containers whenever possible, and support refill and reuse programs. Modelling published by Ellen MacArthur Foundation in November 2023 demonstrated that increased use of returnable plastic packaging could reduce greenhouse gas emissions by up to 69%, water use by 70%, and material use by 76%. Oceana analyzed forecasted packaging market and aquatic plastic pollution data and determined that just a 10-percentage point increase in reusable packaging by 2030 can eliminate over 1 trillion single-use plastic bottles and cups.

There are a number of businesses that support refill like Re-Up Refills, FillGood, and Algramo.

Unilever has pledged that by 2025 that they will halve the use of virgin plastic in our packaging and remove more than 100,000 tonnes of plastic entirely. They have piloted refill stations across the world.

Choose Sustainable Materials

When packaging is unavoidable, choose materials with lower environmental impact like recycled paper, cardboard, or truly compostable materials certified for local composting facilities. Products made from corn and potato tend to break down faster and have fewer impacts on the environment.

Advocate for Systemic Change

Support policies that promote extended producer responsibility, encourage responsible packaging practices, and invest in infrastructure for widespread composting access. Volunteer or reach out to organizations doing this work like Beyond Plastics, Save Our Shores, and Oceana.

Food producers often want their customers to see the product inside a clear wrapper and not cover it with too many logos. Therefore the use of a simple, officially recognised logo is vital to ensure that both consumers and organic waste management operators can easily recognise suitable materials.

Educate and Empower

Raise awareness about the limitations of compostable packaging and encourage consumers to make informed choices based on local composting options and overall product sustainability.