11 Feb Eco-terminology: Biodegradable & Compostable – what’s the difference?
This week, we’re joined by #EthicalHour sponsor Tipa® to discuss the difference between two popular eco words – Biodegradable and Compostable.
This guest post is part of the #EthicalHour sponsorship programme – written by Tipa®:
Today, as flexible packaging flaunts new labels, it is important to be able to distinguish between the different terminology. What does ‘biodegradable’ mean? What does ‘compostable’ mean?
Compostable items are biodegradable, but biodegradable items are not necessarily compostable.
Let’s break it down…
Although both terms yield favourable connotations – namely, something that goes back to nature – ‘biodegradable’ products aren’t necessarily safe for the environment.
The European Bioplastics glossary states that there are no overarching standards that biodegradable products must adhere to, including no deadline as to when a biodegradable product will decompose.
This is crucial when discussing plastic pollution which lingers around for centuries.
“Biodegradation is a natural chemical process in which materials are being transformed into natural substances such as water, carbon and biomass with the help of microorganisms. The process of biodegradation depends on the environmental conditions as well as on the material or application itself. Consequently, the process and its outcome can vary considerably.” – European Bioplastics
Breaking down into natural substances is all well and good but how long does it take to break down – a year, five years, a century?
By this definition, almost anything can be called ‘biodegradable’, and in the meantime, these materials are causing pollution on earth.
Ohio State professor Frederick Michel posits that polyethylene, the most widely used plastic, technically biodegrades 0.1% every 10 years if present under soil. Dr. Michel quips, “Is it therefore biodegradable?”
The European Bioplastics website adds that “It is misleading to merely claim biodegradability without any standard specification. If a material or product is advertised to be biodegradable, further information about the timeframe, the level of biodegradation, and the required surrounding conditions should be provided, too.”
Compost: a circular waste stream
The term ‘compostable’ cannot be earned easily. Unlike ‘biodegradable’s definition, ‘compostable’ items are defined by specific standards.
The European standard on industrial composting, EN 13432 states the following criteria for compliance:
- Disintegration – the packaging sample is mixed with organic waste and maintained under test scale composting conditions for 12 weeks after which time no more than 10% of material fragments are allowed be larger than 2mm.
- Biodegradability – a measure of the actual metabolic, microbial conversion, under composting conditions, of the packaging sample into water, carbon dioxide and new cell biomass. Within a maximum of 6 months, biodegradation of the test sample must generate an amount of carbon dioxide that is at least 90% as much as the carbon dioxide given off from the control or reference material.
- Zero environmental impact – there must be an absence of any negative effect on the composting process into natural soil.
The composting process of a recognised “compostable” product would take approximately up to a year, whereas biodegradable products have no clear timeframe to adhere to.
So, when it comes to buying a biodegradable item or a compostable one, know that the latter had to undergo more scrutinous testing than the former. The European Bioplastics thus urges to “focus on the more specific claim of compostability.”
The extra benefit of implementing compostable products
37 million tons of the food that gets wasted every year ends up in landfill. The food we toss doesn’t break down for decades in the anaerobic environment of a landfill and is basically mummified. A pack of hot dogs, a guacamole order and your apple core remain embalmed due to the lack of oxygen and presence of strong-barriered plastic garbage bags we wrap trash in. The stagnant decomposition rate of landfill food waste not only contributes to methane emissions but is taking up space, while it could be nourishing land instead and turning into compost, or recycled into edible food.
Why are we bringing up food waste in an article about compost? Because fully compostable packaging is designed to be treated just like organic waste. Organic waste and compostable packaging share the same circular end-of-life, nourishing the earth in the form of soil nutrients. Implementing compostable packaging in lieu of conventional plastics will bring about a waste management solution for organic waste disposal as well.
Europe is making headway in sustainability, moving toward a circular economy. The EU has pledged that by 2023, member states will be responsible for ensuring that organic waste gets disposed of properly. The world is reaching a point where plastic and food will no longer take up space and polluting in landfills, which the USEPA estimated in 2015 collectively makes up 28% of landfill waste.
A great feat
Science has ushered us into an era where flexible packaging can be disposed of in a compost system, turning into soil nutrients at the end-of-life. Reusable products are the best way to combat plastic pollution and implement sustainability, but in our world of instant consumerism, on-the-go packaging cannot yet be ruled out of practice, and thus we turn to alternatives such as compostable packaging.
Replacing conventional, single-use plastic with compostable packaging can prevent the accumulation of plastic in our oceans and ecosystems, and slice landfill mountains down in size. Packaging is something that nature has already created, and it makes a lot of sense to learn from orange peels and avocado skins when designing our own packaging.