Warning! Biodegradable ≠ Compostable ≠ Naturally Degradable!

"Biodegradable" and "compostable" are not the same concept, and neither equals naturally degradable plastics. Today, the editor of Jushi Chemical will walk you through the differences between these three terms!

1. What does "biodegradable" mean?

A biodegradable substance refers to any material that can be broken down and assimilated into the natural environment by microorganisms such as bacteria and fungi. Biodegradation is a naturally occurring process.

For example, vegetable peels, eggshells, paper and garden waste are directly biodegradable. When discarded, these materials decompose within a relatively short period and can be integrated into the natural environment. In contrast, foamed plastics, conventional plastics and aluminum are generally regarded as non-biodegradable, as their decomposition takes an extremely long time.

It should be noted that most consumer products labelled "biodegradable" can hardly be assimilated into soil through natural biodegradation. To achieve biodegradation, they require specific conditions created in a composting process.

2. What does "compostable" mean?

The term "compostable" describes products or materials capable of biodegradation under specific, human-controlled environments. Unlike fully natural biodegradation, composting requires human intervention.

During composting, microorganisms break down organic matter with human assistance. Humans supply water, oxygen and organic materials to maintain optimized conditions. The composting process usually takes several months to 1–3 years. The timeline is affected by variables including oxygen, moisture, light and composting environment types. There are two main categories of composting:

Home Composting Home composting involves collecting food scraps in bins or piles, mixing them with yard waste, and regular turning to break materials down into simpler organic substances. For this reason, items such as meat, cheese and fish cannot decompose in home compost bins, because sufficient heat cannot be generated.

Commercial Composting Commercial composting involves sorting organic and inorganic materials, shredding and grinding materials with chippers and grinders, and maintaining optimal humidity, temperature and oxygen levels. Therefore, commercial composting facilities can break down more complex products than home compost systems.

3. Biodegradable and Compostable Plastics

If you have recently purchased phone cases, tumblers or reusable shopping bags, you may have come across biodegradable and compostable plastics, also known as bioplastics. Many restaurants have started using bioplastics for takeaway containers, tableware and cups. These items are commonly made from corn starch, cellulose, soy and other raw materials. With proper composting treatment, they break down into non-toxic carbon dioxide, biomass and water.