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Biodegradable plastic!

Define biodegradable
Define compostable
Can plastics be biodegradable?

The production of biodegradable plastics has jumped from 1.5M metric tons to almost 5.3M in recent years, but are these materials are helping, or hurting the environment?

Biodegradable (oxo-degradable) plastics are often claimed to be sustainable and better for the planet. These properties are inaccurate and misleading. Not only are biodegradable plastics made from fossil-fuels, they also end up creating microplastics and contaminating other plastics recycling streams.

Definitions

  • Biodegradable: microorganisms in the environment break materials down into natural substances, such as water, carbon dioxide and compost without the need for artificial additives.
  • Compostable: materials that are suitable for microbial treatment in composting facilities, which enable specific conditions like temperature and moisture to turn the plastic into usable soil conditioner.
  • Biobased: material or product derived from biomass, plants such as sugarcane corn or cellulose, examples include common plastics such as PET. However PET is NOT biodegradable.

For a polymer to be categorised as “biodegradable”, more than 60–70% of it must degrade within 6 months. PET cannot meet these conditions and is therefore categorised as a non‐biodegradable polymer

  • All plastic, including biodegradable and compostable types must be collected and paired with the right recovery systems, so that the material stays in the loop and out of nature.
  • Biodegradable plastic does not have defined conditions for breaking down the same way compostable plastic does, and this creates a problem.
  • Biodegradable plastic is tested to make sure that it breaks down under controlled conditions in a lab, including factors such as oxygen levels, UV exposure, temperatures, and others. But nature does not have controlled conditions!

So,…. should we use biodegradable or compostable plastic?

Both compostable and biodegradable plastic should only be used when it adds value, makes sense for the product use, and works with the systems that can recover it.

Do not be distracted. We must also focus on what we know works: reducing plastic!

Did you know?

  • The same piece of plastic can only be recycled about 2-3 times before its quality decreases to the point where it can no longer be used!
  • Each time plastic is recycled, additional virgin material is added to help “upgrade” its quality

——— National Geographic

References:

BiopPak

World Wildlife Foundation – further reading on The WWF position on biobased and biodegradable plastic here

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