Biodegradable Vs Compostable, What’s The Difference?

Most of us have recycling down to a fine art now. We wash and separate our packaging and put the right items out for the curbside pick-up.

But many manufacturers are now going a step further than just making their plastic bags and other plastic wrappings recyclable. We are seeing more packaging marked ‘biodegradable’ or ‘compostable’ or even both!

This can actually become quite confusing. Should I put my ‘compostable’ plastic waste in my garden compost bin? Can I still put it in the recycle bin if I don’t compost? Or should I put it in my general waste bin, and trust it will break down at a landfill site?

It’s definitely not always clear and the terms biodegradable and compostable seem to be often used interchangeably.

In this blog, we will clear up any confusion and make disposing of these types of plastic simple.

What Does Biodegradable Mean?

The term ‘biodegradable’ is in fact a general term which means any material that can be broken down by microorganisms (like bacteria and fungi) and then is assimilated into the natural environment.

It’s a naturally occurring process found in nature but the term biodegradable can be applied to almost any object. When something degrades, its original composition breaks down into simple components like biomass, carbon dioxide, and water. This process can occur with or without oxygen but is quicker when oxygen is present like when a pile of leaves decays into soil over time.

It’s the length of time that it takes a material to break down - and what it breaks down into - that causes the problems for our environment. How long it takes depends on what the item is made from and other variables like the amount of water, light, heat and oxygen available.

Most landfills have so little light, air, and moisture that the biodegradation process is significantly slowed.

This means that materials like styrofoam, plastic, and aluminium are typically deemed non-biodegradable because of how long they take to break down.

Is There Biodegradable Plastic?

Unfortunately, there currently isn’t a widely recognised standard or logo for degradable plastics in the UK. Most will have the word ‘degradable’ on them somewhere, often accompanied by imagery suggesting that the product is ‘eco-friendly’. But, beware, they could be made of petro-chemicals and not necessarily derivatives of natural materials such as cornstarch.

These plastics can’t go in the recycling bin, as they will contaminate otherwise recyclable materials, and can’t go into your home composts as they need to be industrially composted.

Be careful of items claiming to be biodegradable as there’s a lot of ‘greenwashing’ going on, with manufacturer’s typically using their own symbol, only to denote the product meets with their own standards.

Brands are able to use broad-sweeping claims, such as ‘biodegradable’, and even ‘green’, ‘eco-friendly’ or ‘sustainable’ because these words have no clearly defined meaning. This means that these types of terms are not breaking any particular advertising rules.

There is no specific anti-greenwashing legislation in the UK, despite this form of greenwashing being so confusing to customers.

So, if you’re trying to work out whether something is biodegradable, check the packaging and don’t hesitate to contact the company to ask questions.

It’s important to remember that the term biodegradable can be misleading and biodegradable materials are not necessarily compostable.

What About Bioplastics?

Bioplastic is a term used to describe what a plastic is made from and has no bearing on how it degrades.

As you know, standard plastics are made from fossil fuel-derived ingredients, whilst bio-plastics are made from ‘naturally’ derived materials such as vegetable fats and oils, corn starch, straw, wood chippings, sawdust, or even algae and seaweed. These materials typically contain high concentrations of cellulose, starch or lactic acid.

Some bio-plastics may be manufactured containing a mixture of both fossil fuel and natural derived materials. A manufacturer may choose to show the percentage of non-fossil fuel-derived content on a label - or not!

There is huge potential for confusion between the words bioplastic and biodegradable, and manufacturers have been advised that it is best practice to use terms such as “plant-based” or “bio-based” instead. But this is simply advice and not yet a legal requirement.

Again, it’s important to be aware that bio-plastics aren’t necessarily biodegradable. Those that are biodegradable will be labelled as such, but otherwise, it’s best to assume that the bioplastic is materially identical to a regular plastic and the product might take a long period of time to break down in the environment, and can still produce microplastics.

So, What Are Compostable Products?

When we think of compost, most of us think of garden waste - such as leaves, grass clippings and non-animal food waste. But the term can also apply to anything made from organic matter which will break down in less than 12 weeks and will improve and create nutrient-rich soil. The composting process allows organic carbon to return to the earth.

Compostable items are made from materials that have been certified to break down completely into non-toxic components (water, carbon dioxide, and biomass) and that will not harm the environment, given the right environment. When the item is fully composted, it will have left no toxic residue in the soil.

The time it takes for something to break down depends not only on the product itself but also on the composting conditions - and this is where things can get confusing.

Composting At Home Vs Industrial Composting

So everything that is labelled as compostable must be beneficial to the environment, right? You might assume so. The term "compostable" is not without controversy, though. The phrase can be used to refer to both products that are only appropriate for use in home compost setups and those that can only break down in an industrial composting facility.

Composting at home is perfect for most food and organic waste, however, it doesn’t create the right conditions to break down many types of compostable packaging, such as coffee cups and other food packaging. This is because in most garden compost heaps, the temperature is much lower and much less constant than in an industrial composting facility, so this packaging cannot be broken down at home.

Food packaging labelled as compostable is not usually suitable for home composting. In fact, there is no accepted UK standard for such material for home composting, and most councils will not accept them with garden waste or food waste, so it is always important to check first.

Take, for example, coffee cups lined with PLA - a bioplastic made from cornstarch. These are compostable but are not suitable for home composting. PLA needs processing by an industrial facility.

Unfortunately, we don’t have many of these facilities in the UK - there are currently just 50 - and only a portion of them now accept and handle industrially compostable packaging. This means that many local governments just don’t have access to this kind of facility. It also makes it nearly impossible to properly discard commercially compostable packaging.

To make matters worse, if industrially compostable materials are put in your household waste bins, they will have to be fished out and sent to landfill. This makes these types of compostable packaging worse for the environment than recyclable plastic.

Fortunately, some companies are moving forward with producing plastic bags that are home compostable. Plastics that are certified as being home compostable are designed to break down quickly in a home compost bin but may be slow to do so, particularly if you have more than a few small items to dispose of, or if your compost bin is not working properly.

Remember that home compostable plastics are non-recyclable. They should not be placed in your kerbside recycling collection as they may contaminate otherwise good, recyclable materials.

What To Remember About Biodegradable And Compostable Materials

It would be difficult to avoid everything biodegradable because, given enough time, almost everything will decompose. But to make the best choices for the environment, don’t be greenwashed by claims of ‘biodegradable’ products or ‘compostable’ coffee cups.

Choose reusable things whenever possible, or recycle as much as you can. Begin to ditch any single-use plastic, however green it might appear. Everything else, even packaging marked as biodegradable and compostable (unless it can be picked up by your local authority or is suitable for home composting), should be disposed of with general rubbish.

-

Wild & Stone's mission is to create stylish, easy to adopt and usable alternatives to common plastic products around the home. We source all our products sustainably, from raw material to final delivery. Shop our wide range today.