Compostable and Biodegradable Plastics

Compostable and Biodegradable Plastics

What are biodegradable and compostable plastics?

Biodegradable and compostable plastics are alternatives to traditional, persistent plastics like
PVC, and are designed to break down much faster.

Why use these alternative plastics?

In an effort to curb plastic in landfills and ocean gyres, many business adopted the use of these alternative plastics. With prefixes like “biodegradable” and “compostable”, they certainly sound more beneficial to the environment!

Alternative types of plastic

Bio-based plastics are derived from sources such as algae, microbes, and plants, as opposed to conventional plastics which are based on fossil fuels. These bio-based plastics are still chemically identical to regular plastic and don’t necessarily biodegrade at all. It is just that they are using plants as a source of carbon instead of petroleum.

Not necessarily bio-based; a plastic that can be broken down by the action of living organisms into simple chemical constituents, such as carbon dioxide, methane, and water, does not speak to the quality or environmental fitness of the degraded material. There is no time restriction on how long it must take to biodegrade, or what the environmental conditions must be. This is a loose definition. What is known, however, is that biodegradable plastics will not biodegrade in the ocean – it is too cold.

Not necessarily bio-based; breaks down into organic material suitable for plant growth, cannot leave toxic residues. Require very specific conditions (high heat, lots of oxygen, specific microbes) that are only found in industrial composters, not in backyard composts. Most of industrial compost facilities don’t compost long enough for the compostable plastics to actually compost at all. Eventually, these plastics are sent to the landfill, where they definitely won’t compost

Plastics that contain additives known as pro-oxidants, typically metal salts, that are designed to accelerate degradation without any help from microbes. Not allowed in compost bins. Basically just become microplastics faster than regular plastic.

Like most plastics, these alternatives are cheap to make and versatile. But, as they have become more widespread, and the public has learned more about their chemical nature, some problems with these “eco-friendly” plastics have become clear.

The Problem

The problem with these degradable plastics is straightforward: typically they degrade into microplastics, and in the process can release non-plastic toxins, dyes, and chemical stabilizers, including compounds such as BPA, into the surrounding environment.

Rarely Processed or Recycled Correctly

Compounding the problems of toxic residues and microplastics that end up in our soils and water systems, many of these alternatives to traditional plastics are difficult to process/fully recycle, and institutional infrastructure is lacking for the collection and transportation of these alternative plastics to the correct facilities.


Refuse single-use plastics when you can. Remind consumers and businesses that these alternatives are a form of greenwashing and their better off bringing their own cup, or saving their money.
The planet will thank you.