What are bioplastics?
Bioplastics are a family of materials made from bio-based sources or biodegradable materials. In some cases, a bioplastic may be both bio-based and biodegradable.
Substances used to manufacture bioplastics include vegetable fats and oils, sugar cane, woodchips and agricultural by-products like corn starch. Due to their natural ‘biological’ sources, these polymers are referred to as bio-based plastics.
Biodegradable plastic is a polymer that can be completely broken down into natural substances (such as biomass, carbon dioxide, water and methane) by biological organisms like microbes.
Types of bioplastic
There are lots of different types of bioplastics with various characteristics and uses. However, to be considered a bioplastic, a polymer has to meet one or both of the following criteria:
- Being made from renewable, naturally sourced raw materials
- Being biodegradable in the natural environment without causing damage or pollution
This means a polymer made from oil that’s biodegradable also counts as a type of bioplastic. So just because a polymer is a bioplastic doesn’t mean it has zero environmental impact. Indeed, there are some polymers that don’t fit bioplastic criteria but generate less waste and carbon footprint than traditional plastics.
Compostable plastics break down only under carefully controlled conditions using industrial composters or home composting. Materials designed to safely break down in industrial composters may not do so under home composting conditions, and vice versa.
Oxo-degradable plastics are made from fossil fuels enhanced with additives that help the plastic to degrade more quickly than standard polymers. However, oxo-degradable plastics don’t break down completely like the other two. Instead, they fragment into ‘microplastics’ which are pieces of less than 5mm or 0.2 inches in length. These pieces can still cause significant environmental damage.
