Biodegradable vs. Compostable: What's the Difference?

By Maureen Wise in Thinking Sustainably

There are a lot of labels on consumer packaging nowadays, including "organic," "natural," "biodegradable," and "compostable"—but it's not always clear what they mean. What makes something biodegradable? What's the difference between biodegradable and compostable? Let's compare biodegradable vs. compostable products and break down the differences—pun intended.

Why Is Breakdown Important?

Let's start with why we want products to break down to begin with. Most packaging and products that are intended to be used once and then discarded can be recycled, which is great. Reusing resources to make something new is ideal. It means we don't need to dig new metal out of the ground or drill for oil. However, some products can't be recycled.

Sometimes, it's because the item is made of a blend of materials. Bioplastics can't be recycled with oil-based plastics. To-go containers such as hot cups often have a wax lining that makes them unable to be recycled, too. Therefore, making products such as these biodegradable or compostable is a great way to reduce waste. However, you have to get them to the right place so that they can actually break down, which can sometimes be a challenge.

Woman with long curly hair planting seedlings in compostable starter pots at a counter

Biodegradable vs. Compostable

By definition, everything that is compostable is also biodegradable. However, not all biodegradable products are compostable. What's the difference?

What Is Biodegradable?

The process of biodegrading is natural. It refers to the breakdown of organic matter via microorganisms, such as bacteria and fungi. Leaves on the forest floor biodegrade and add nutrients to the soil, as do grass clippings left on your lawn after mowing. Factors such as moisture, temperature, light, and the amount of oxygen all affect the rate of deterioration.

Oil-based plastics never biodegrade. They just turn into smaller and smaller pieces and eventually turn into microplastics. The term biodegradable is not currently regulated in the United States, so when you see this on a product label, do your research. It can be tricky not knowing whether the product is truly biodegradable or under which conditions it can biodegrade.

What Is Compostable?

If something is compostable, it means that it can break down in a compost pile. Collecting food scraps and garden waste helps to speed up decay and reduce these items into an extremely useful fertilizer. There are two main types of compost: backyard or home compost and industrial compost. In our home compost bins, we have much less material, and the temperature doesn't get as high. Industrial composting facilities have a larger capacity, allowing them to collect from individuals and businesses. The larger the quantity of compost collection, the hotter it gets.

For instance, dog waste bags that are labeled compostable and are made from bioplastic will not decompose in your home compost, but they will turn to compost in an industrial compost facility (if they accept pet waste in the first place—check with your local facility!). The same goes for all compostable bioplastics. Additionally, meat bones, eggshells, and dairy products will turn into compost at higher temperatures but won't break down in a home composter. Products that are labeled as compostable are regulated. They must meet US industrial composting standards, which means they'll decompose in 90 days and will not release any harmful residues into the compost. To test this, they germinate seeds in the composted material and evaluate the baby plant for toxins.

Some products are both biodegradable and compostable. Cardboard plant starters, for instance, will break down when planted in the soil, and they'll also decompose in any compost pile. The main distinction between biodegradable and compostable materials is that the composting process demands distinct conditions in order to decompose, while truly biodegradable materials will break down on their own without human intervention.

black woman with white shirt drinking from clear reusable water bottle with silver base

Which Type of Product Should You Choose?

When you're choosing what to buy, the best purchases are durable products that you can use over and over. Use a reusable water bottle, mug, or cup instead of a single-use water bottle or a single-use plastic cup. Consider bringing your own containers to a restaurant to store leftovers. When you don't have a reusable option, do some research to discover if there are biodegradable or compostable alternatives, such as with doggie waste bags.

In many cases, it's probably better to choose a bio-based plastic over an oil-based plastic for the sake of the Earth, but only if you have access to an industrial compost facility that can reduce it back into its natural form. Otherwise, choose recyclable plastics.

Want to learn more? Check out this article on everything you need to know about bioplastics.

Image Source: Pexels | Pexels |Pexels

The views and opinions expressed in any guest post featured on our site are those of the guest author and do not necessarily reflect the opinions and views of Tom's of Maine.

Why It's Good

Understanding how different ecological systems work can help you cut through greenwashing and support brands that have your same Earth-minded ethos.