6 Facts About Biodegradable Plastic

Biodegradable Plastic Cup

Petroleum-based plastics, also known as conventional plastics, are a scourge on our planet, polluting our oceans and waterways, killing marine life, and overflowing our landfills. The need for biodegradable plastic, which naturally breaks down in the environment, has never been greater. However, there are some misconceptions about biodegradable plastic, and plastics in general. To clear up some of the misunderstandings, here are some interesting facts about biodegradable plastic.

1. Both biodegradable plastic and conventional plastic break down in the environment, but at different rates.

All plastic will eventually break down in the environment. But it’s important to distinguish between plastics made from organic materials and those made from petroleum. The problem with petroleum-based plastics is that they’re made from ancient, fossilized substances, so microorganisms don’t readily recognize them as food. Thus, petroleum-based plastic can take over 1,000 years to break down in the environment. Biodegradable plastics, on the other hand, can decompose in six months under the right conditions.

Conventional plastics, which are derived from fossil fuels, including natural gas, crude oil, and coal, are the most commonly used plastics today. The most widely used of these types of plastics are polyethylene terephthalate (PET), polyethylene (PE), polypropylene (PP), and polystyrene (PS).

Plastic Fragments

While microorganisms don’t readily break down conventional plastics, these plastics do break apart into small fragments or microplastics. These tiny particles of plastic can easily get into our soil and waterways. But unlike microorganisms, fish and other aquatic animals easily mistake plastic particles for food, or they simply ingest pieces of plastic because there is so much of it in our rivers and oceans now.

Since conventional plastic is made from chemicals that are unnatural for living organisms to ingest, when living beings eat microplastics, they are ingesting materials that can be quite toxic to their systems.

The chemicals in petroleum-based plastics can also be toxic to human beings. Chemicals from conventional plastics have been proven to leach from plastic containers into the foods and beverages that we consume, causing a host of health issues.

Conventional plastics also degrade when they’re exposed to ultraviolet light. And when they do, they leach harmful petrochemicals into the environment. By contrast, when biodegradable plastics break down, they generally don’t release toxic chemicals into the environment.

2. Biodegradable plastic can easily breaks down in the environment – under the right conditions.

Biodegradable plastic is made with organic material, not fossil fuels, so it’s readily recognized as a food source by bacteria, fungi, and other microorganisms. However, decomposition of biodegradable plastic is not guaranteed. Certain environmental conditions need to be met, such as adequate light, heat, moisture, and oxygen, for total decomposition to occur. Just like you, microorganisms don’t feel like eating in certain situations.

Some biodegradable plastics will easily break down in a residential composting service, but they may not breakdown in a landfill environment because the conditions are not ideal for microorganisms.

The ocean is one environment that is not ideal for the decomposition of biodegradable plastic. Most microorganisms favor warmth and oxygen, conditions that are not generally present in the ocean. Thus, biodegradable plastics disposed of at sea can be harmful to marine life.

3. Setting internationally recognized standards for biodegradable plastics is complicated.

Currently, there are no internationally recognized standards for biodegradable plastics related to their ability to decompose in landfill. Extensive testing still has to be done on different types of plastics that are made with biodegradable materials to assess how well and how quickly they break down in typical municipal waste treatment facilities and landfill environments.

Different countries, and even different U.S. states, have their own standards for plastic biodegradability, as well as whether or not biodegradable plastics can be disposed of in residential compositing systems.

Generally, plastics are considered biodegradable if 90 percent of the materials break down into CO2 in an aerobic environment within six months.

4. Not all biodegradable plastics are compostable.


Even though a plastic may meet generally accepted standards for biodegradability, it doesn’t mean you can just throw it into your home composting bin. Even biodegradable plastics require high temperatures, a certain level of pressure, and precise nutrient and other chemical conditions to be properly composted. Not every residential compositing service can provide these conditions, so if you have an item that is made with biodegradable plastic, such as a Pela Case phone case or World Centric cutlery, contact your local waste management service and ask if they accept biodegradable plastic.

5. Biodegradable plastic is not recyclable in the way conventional plastic is.

Biodegradable Plastic Food Container

Some, but not all, conventional plastics can be mechanically and chemically broken down, or recycled, and turned into new plastic materials to make a number of products, such as shoes, sunglasses, frisbees, phone cases, and dog collars. However, recycling plastic can be challenging because different types of conventional plastics don’t necessarily blend well together to make new materials. Thus, conventional plastic that’s thrown into your curbside recycling bin has to be sorted, which adds a level of complexity (and labor hours) to the process.

Furthermore, unlike glass, when plastic is broken down and recycled into newer plastics, the quality of the material degrades. Thus, conventional plastic can only be recycled two-to-three times before the quality degrades to the point that it can’t be used anymore.

Currently, with biodegradable plastics, recycling is even more complicated, if not impossible. According to the Ecology Center, most biodegradable plastics have a #7 recycling designation. And unfortunately, many municipal recycling centers don’t accept #7 plastics because they’re simply not set up to recycle that kind of material.

6. Bioplastic is not the same as biodegradable plastic.

Zeal Optics Cellulose Acetate Bioplastic Sunglasses
Cellulose Acetate Bioplastic Frame Sunglasses by Zeal Optics.

Bioplastics are another category of plastics that are made with organic materials, such as corn, sugarcane, and plant cellulose. However, bioplastics are not necessarily biodegradable or compostable. The reason is these plastics may also contain inorganic materials, such as petroleum-based polymers. While it’s generally preferable to buy plastic products that are made at least partially with organic materials vs. entirely of petrochemicals, it’s important to know that not all bioplastics are biodegradable.

So, where does this leave us? While strides are being made to produce more eco-friendly plastics, the industry is still in its infancy when we consider just how ubiquitous petroleum-based plastics still are in our society. However, if we consider the fact that nearly 130 countries around the world now have some kind of regulation in place for plastic bag usage, it shows that we humans are capable of changing our behaviors when it comes to plastic consumption on a grand scale.

As we go about our days, we should all be looking for alternatives to single use, petroleum-based plastics. This could mean buying food in the bulk section, carrying a reusable grocery tote or water bottle, and even picking up after our pups with biodegradable poop bags. We all want a healthier world and kicking the conventional plastic habit is one way to get there.

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