The difference between biodegradable, compostable and bio-based
In sustainable industries, terms such as biodegradable or compostable are regularly used. Often these are mistakenly equated with each other. So, what are the differences? We will give you a brief definition of the similar sounding but dissimilar words.
What does biodegradable mean?
A product is considered to be biodegradable if it can be decomposed into carbon dioxide, water and biomass by biological processes - for example by the activity of microorganisms or enzymes. The main point here is that the product is degraded down to the basic molecules Co2 and H2O. If this is not the case, micro-particles can remain in the environment, potentially causing great damage. It is important to note that biodegradable is not the same as compostable, as this is about the time it takes for a product to degrade. For example, a product that takes 100 years to break down into its basic molecules would be biodegradable, but only compostable if the process could be accelerated to 90 days under the right conditions. Products made from biodegradable materials therefore rather belong into the recycling bin. You can find out more about the recycling of biodegradable or compostable products in our article on recycling.
What does compostable mean?
A product is only compostable if, under certain conditions and within a fixed period of time, it can be decomposed into carbon dioxide, water and a fraction of the original mass (10%) without leaving toxic residues. This decomposition process should take place solely with the help of microorganisms or enzymes. This process is faster in industrial composting plants than on a compost in the garden. This is largely due to the temperature that prevails there: in an industrial plant, the temperature is around 60 degrees. In this case a compostable product should be metabolised within 3 months. It only becomes problematic with products that take the full 90 days to decompose. Why? Often the compost cycles in such plants are much shorter and so the substances cannot be completely converted. In garden compost, on the other hand, the temperature is only around 30 degrees, depending on the season. Here, the natural composting process may take up to a year. In Germany and the EU in gerneral, there is a standard procedure (DIN/EN 13432) to which companies with corresponding products can voluntarily commit themselves. In our article on DIN/EN13432, we explain which requirements must be met in order to be allowed to call a product compostable according to the DIN/EN standard.
What does bio-based mean?
Bio-based materials are made from biomass, such as sugar cane and corn starch. However, these substances do not have to consist of 100% biomass, as one might think, to be allowed to call themselves bio-based. They only have to contain at least 40% biomass - in other words, as the name suggests: be based on biomass.
In practice, composites are often used to bind the ingredients together.. We also use a bio-based composite material made of wood fibres and bioplastics. This "bio-compound" does not contain any petroleum and is free of BPA and melamine. The material is temperature resistant up to 70 °C and dishwasher safe. Many bio-based composites are therefore neither biodegradable nor compostable due to the bioplastic content. Nevertheless, they can be considered sustainable because conventional plastic (petroleum-based) is avoided, and the products are reused several times.
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