Biodegradable vs Compostable: Understanding the Key Differences

Introduction

Biodegradable and compostable plastic options are on the rise, combating the statistic that over 80% of plastics become useless and enter the environment, causing economic and environmental harm (Science Direct).

With an increase in sustainability awareness, labels like “biodegradable” and “compostable” are all around, but what do they really mean? Opting for these alternatives is morally appealing; however, is one preferable to the other, and after making this decision, how do we dispose of these options?

"Understanding our sustainability choices matters."

For businesses, understanding the difference between bioplastics—their composition and how they decompose, is important to make a positive impact. Making choices on what to stock in your office space, how to ship or receive products, and how to encourage such practices within your organization requires understanding what bioplastics are and how to deal with them. Using bioplastics effectively can ultimately help you reach your sustainability goals of a greener workplace or organization.

What is biodegradable?

Biodegradable is one alternative to plastic, with rising opportunities for businesses to participate. Biodegradable products are made of petroleum sources, each with different compositions and properties that give it unique functions. Within the business industry, this can look like biodegradable packaging materials, office supplies, and to-go materials.

For biodegradable products to decompose, they need the help of natural organisms such as fungi, bacteria, and algae. Degradation for biodegradable materials is unspecified, ranging from a year and beyond.

Biodegradable products and labels are less regulated, leading to confusion and misconceptions. While biodegradable plastic options are preferable to plastic, they don’t function at the same level as compostable products, as they have longer degradation times and leave a residue.

What is compostable?

Broadly, compostable refers to materials that can break down into nutrient-rich soil through a controlled process, leaving no toxic residue. Commonly, compostable materials are organic matter, such as food scraps and grass clippings; however, compostable plastics complicate the idea of what “compostable” means.

Compostable plastics are made from either petrochemical or renewable sources. They naturally decompose into CO2, inorganic substances, and biomass, without leaving any toxic residues—just like organic matter. In its final product, compost can be implemented in agricultural and horticultural spaces as nutrient-rich soil. Composting standards by the American National Standards Institute require 90% of composted materials to be turned into CO2 within 6 months.

Composting can be done on two levels: home composting and industrial composting. Home composting systems process natural materials slowly but effectively. Industrial facilities move materials through the composting process much faster, as they can closely control the environment to make it conducive for quick decomposition, creating the same end product as home composting. Industrial facilities are preferable for compostable plastics, as the products have a slower decomposition rate than conventional organic composting products. In an industrial composting facility, compostable plastic should degrade in 3 to 6 months per EPA requirements.

In commercial settings, compostable plastics can be found as packaging materials and to-go cups and containers. One example of successful compostable materials is Alter Eco’s transition to home-composting-friendly truffle wrappers using compostable packaging derived from eucalyptus and birch trees. Another success story is Ecovative Design’s “mushroom plastic” packaging, a fully compostable option made from mushroom roots with self-bonding properties. Sourcing products like these, or taking inspiration for your business plan, can push you in the direction of your sustainability goals.

Key differences: Biodegradable vs compostable

So, how much of an environmental impact are we making by using these alternatives?

Let’s start with biodegradable plastics. The impact of biodegradable plastics is only positive if they are handled correctly; putting them in the wrong stream can cause harm. However, if they are managed properly, they can be beneficial in limiting plastic that ends up in landfills by offering an alternative product.

Compostable plastics are preferable. These products, if handled correctly, leave no trace. Since compostable plastics have to follow strict regulations, their labeling is more accurate. But, like biodegradable plastics, they must be handled properly. Ending up in the recycling can contaminate an entire stream.

Both plastic alternatives require industrial composting facilities and diligent care. Making the choice to buy biodegradable or compostable products is only environmentally friendly if they are handled carefully. Buying them isn’t enough on its own to make an impact.

Common misconceptions

“Greenwashing” is making it harder for individuals and businesses to make sustainable choices. Many companies want to be “green,” but putting that into practice is harder than just sticking a label on their products. The array of labels on products makes them challenging to understand, especially when we don’t know how to differentiate them. So, to clarify some misconceptions that have occurred with greenwashing, here are some myths debunked:

• Myth: All biodegradable products are compostable.
  • False, biodegradable, and compostable are different. The main difference is that biodegradable products will eventually degrade but leave behind a residue, while compostable products break down into CO2, water, and inorganic materials, which make up nutrient-rich soil.
• Myth: Biodegradable and compostable plastic will decompose anywhere.
  • False, biodegradable and compostable plastics should be disposed of in industrial composting facilities. Some compostable plastics will have an “at-home compostable” label if they meet requirements to decompose in home composts, but most products should go to the larger composting facilities. If this is not an option, these materials should go to the landfill. Avoid throwing any biodegradable or compostable waste into recycling streams, as they can cause contamination.
• Myth: All biodegradable items are made from plants.
  • False, biodegradable products can be from plants and petroleum sources.

How to properly dispose of each product

Biodegradable and compostable plastics can be thrown in industrial composting facilities. Some compostable products, if labeled specifically, can be disposed of in at-home composting facilities. If these are not accessible, the landfill is your next option. While not preferable, using the landfill keeps these materials from contaminating recycling streams. It’s important to read labels carefully and refer to other resources before disposing of these items, as regulations vary from state to state.

Conclusion

While biodegradable and compostable plastics are viewed as “green” choices, they must be handled with care to actually benefit the environment. Within the workplaces and professional settings, clear labeling and waste management encourage positive practices regarding plastic alternatives. Check out the Sustainability Collection to manage your waste separation and work towards your sustainability goals!