Bioplastics: bio-based and biodegradable are not the same thing
"Bioplastic" sounds like a promise: a plastic from plants that would return to the earth. In fact the word covers two independent properties, and a single pack can have one without the other.
By Tecmom editorial team · 2 min read
Two different questions
The European Commission carefully distinguishes two things.
- Bio-based says where the material comes from: a plastic made, wholly or partly, from biological resources such as sugarcane or maize.
- Biodegradable says what becomes of it: a plastic that micro-organisms can break down, under given conditions.
The two do not necessarily go together. A bio-based plastic is not necessarily biodegradable; a biodegradable plastic can be made from oil.
Two examples that clear things up
Bio-based polyethylene, made from sugarcane ethanol, is chemically the same polyethylene as the oil-based kind. It is moulded and recycled the same way, and it is not biodegradable.
Polylactic acid, or PLA, is also bio-based, and it is compostable, but in industrial composting, at a temperature a garden compost heap does not reach. Thrown into nature, it does not disappear quickly.
Compostable, a special case
Compostable plastics are a subset of biodegradable plastics: those that break down in a composting facility, usually industrial, after collection. A harmonised European standard defines what industrially compostable packaging is.
In 2022 the Commission published a policy framework on these plastics. It is not binding, but it clarifies the terms and notes that no EU law yet covers them comprehensively.
And for healthcare packaging?
For a medicine, the material question is not settled in purchasing. Primary packaging is described and studied in the product's file; changing it, even for a chemically identical material from another source, must be justified to the authority. See primary packaging.
In cosmetics or food, the argument is more open, provided one knows what is being promised: a plant origin, a compostable end of life, or both. See HDPE, PET, PP and cosmetic packaging.
Before writing "bioplastic" on a pack, one has to know what promise is being made. Where the material comes from, and where it ends up: those are two answers, and the word gives neither.
Glossary
- Bio-based
- Made wholly or partly from biological resources.
- Biodegradable
- Broken down by micro-organisms, under given conditions.
- Compostable
- Biodegradable in a composting facility.
- PLA
- Polylactic acid: a bio-based plastic, compostable under industrial conditions.