Biodegradable vs Compostable – Do You Know The Difference?
When it comes to sustainable living, the amount of waste we produce has become a central issue as we discover just how much waste we make and the impact it is having on the planet. Our waste problem is so bad that it’s given rise to the zero waste movement. There has also been an emergence in products claiming to be biodegradable or compostable in response. But are these products actually better for the environment? And what are we really talking about when we consider what is biodegradable vs compostable?
We’ve already gone over what is compostable at home and what is not compostable at home, and how to choose from the best indoor, urban compost bins, and environmentally friendly trash bags. So let’s dive into the need-to-know about what is compostable and what is biodegradable.
What does compostable mean?
If you’ve ever wondered “what does compostable mean?” then you’re actually asking a very good question. Generally, something is compostable if it can be broken down by microorganisms in soil, in the presence of oxygen, and safely go on to contribute to a nutrient-rich organic soil amendment also known as compost.
Though you can definitely try one of these zero-waste meals, composting opens up the door to diverting a lot of waste from the kitchen. You can also compost all kinds of other stuff like natural paper products, toilet paper rolls, and yard waste. Even the handle of your bamboo toothbrush is perfect for a zero waste bathroom.
That said, what is compostable will ultimately depend on what type of composting system is available to you. Things like animal waste, eco-friendly diapers, silicone, and eco-friendly plastic alternatives are not always compostable at home. Here, things get a little bit more complicated.
That’s because there are two types of composting to consider: residential composting and commercial composting. Residential composting is where we collect organic matter like veggie scraps and yard trimmings to create homemade plant food (compost) that can nourish plants and help them grow.
This is a great way of diverting waste to landfill and putting it to good use. Unfortunately, where residential composting is concerned, some organic matter like meat, dairy, and fish are not recommended because of the odor they generate and the pests they may attract–even though they are actually compostable too.
Some veggie scraps like onions, garlic, and orange peels are also not recommended because they can offset the pH balance of your compost heap which kills the worms that help with the decomposition process. So if you’ve ever wondered “what do worms eat” onions and garlic may not be at the top of the list.
Commercial or industrial composting operations work similarly but they can handle a lot more organic waste. With the help of equipment like grinders and chippers, commercial operations can speed up the decomposition process and make light work of composting a wider range of items. Notably dairy and animal products, animal manure, and all kinds of vegetable scraps with no exceptions.
Some commercial operations also accept compostable disposable diapers and compostable bioplastics. Neither are recommended in residential composting. Because of the fecal matter involved in eco-diapers, it is not safe to then apply this compost to plants made for eating. They can also take a long time to degrade.
In the case of bioplastics, they can take a decade or more to degrade in home systems. In fact, if the product says it is "compostable in industrial facilities" that means it needs to be sent to a commercial facility to break down under specific conditions, like the high temperatures that can only be attained in commercial composting systems.
That said, some commercial operations do not accept bio-based compostable plastics or compostable diapers so make sure to double-check before sending this waste over to them. “Wishful composting” will only contaminate the waste stream and give your composting facility more work to do. Ultimately, what is compostable will depend on what type of composting is available to you.
How do you know if something is compostable?
When it comes to products made from bioplastics like disposable cutlery, bowls, and plastic bags, it is best to look for certifications that can attest to their compostability and avoid greenwashing. Back in 2019, some "compostable" bowls were even found to contain forever chemicals also known as PFAS. Though the bowls did break down, the chemicals themselves did not and go on to pollute the soils they are added to.
Certifications from reputable entities like the Biodegradable Products Institute (BPI) come in super handy here. The BPI certification is based on the ASTM D6400 standard and the ASTM D6868 standard. With this certification, BPI ensures that the product in question will biodegrade completely and will not leave any harmful substances behind once it is been composted.
In the US, the ASTM D6400 is the test standard of choice and it is used to determine what solid materials can be labeled as compostable in commercial or municipal facilities. It is globally recognized and was developed for plastics, but can be used to test food packaging, paper products, textiles, and more.
In the EU, the compostability standard is set by the EN 13432. It defines how fast and to what extent a given biodegradable plastic product must degrade under industrial composting conditions (Vrins & Costenoble, 2019). Under this standard compostable materials should disintegrate within 12 weeks of disposal.
In Canada, the standards for compostable plastics are set by the CAN/BNQ-0017-088. It defines the "procedures and requirements for the identification and labeling of plastics, and products made from plastics, that are suitable for recovery through aerobic composting.” In Australia, products must meet the AS4736 which is the Australian Standard for compostability.
That said, it is important to note that compostable products cannot be put into the recycling bin or the paper collection bin. That will contaminate the waste stream.
What does biodegradable mean?
Unlike compostable things, biodegradable things can break down with or without oxygen. Here, microorganisms like bacteria and fungi can break these items down, and turn them into carbon dioxide, water and biomass. Similar to products called “compostable” however, this can leave behind unwanted toxic residue that persists in and/or pollute the environment. So just because something is considered biodegradable doesn't mean it is good for the environment.
Also, something can be biodegradable but not compostable, like some of the bio-based plastics out there. Just as something can be biodegradable and compostable, like an apple core or vegetable scraps.
What's the difference between biodegradable and degradable
Pretty much anything will degrade over time with exposure to sunlight and heat. And that’s just what degradable means. From old plastic toys to plastic bags to discarded electronics. Everything wears away over time and breaks down into smaller and smaller pieces.
Unfortunately, this also poses contamination and pollution issues, where some of the components in things like broken cell phones are toxic and pose a serious threat to water, soil, and air quality when they are left to degrade in the environment. That’s why it’s so important to recycle e-waste properly and to be more mindful about all of the waste we generate.
It’s also important to learn more about the terminology surrounding waste which is why it’s so awesome you are reading this!
The difference between biodegradable and degradable basically comes down to the decomposition process. One occurs with the help of microorganisms and the other with heat and sunlight. In this instance, some things are degradable but not biodegradable like e-waste, and others are degradable, biodegradable, and compostable like food waste.
How do you know if something is biodegradable?
To figure out if something is biodegradable, it is best to refer to certifications here too. The SCS Global Services certification is one such reference. BPI issues certification for biodegradable products as well, along with the Japan BioPlastics Association, and the Federal Trade Commission (FTC).
The FTC sets guidelines for what can be labeled degradable, biodegradable, oxo-degradable, oxo-biodegradable, or photodegradable. Based on these guidelines, all claims should be backed by scientific evidence demonstrating that the entire item will completely break down and return to nature within a reasonably short period of time after customary disposal.
Based on these guidelines, items labeled as biodegradable should completely decompose within one year after customary disposal. Items labeled as degradable should be clearly labeled and speak to the “product's or package's ability to degrade in the environment where it is customarily disposed” as well as “the rate and extent of degradation”.
Why is proper disposal of biodegradable items crucial?
The unfortunate truth is that biodegradable items are not the cure-all many of us may be hoping for. Biodegradable items can go on to pollute just as their conventional counterparts might. That’s why proper disposal of biodegradable items is crucial. If you aren’t sure where to put a biodegradable item, check the packaging. If that doesn’t help it is best to send it to landfill unless you are certain it can be recycled or composted by the services available to you.
Is biodegradable plastic the same as compostable?
Compostable bioplastics and biodegradable plastics are not the same. Where they are actually compostable, compostable bioplastics can be safely discarded at home or commercially composted. Biodegradable plastics on the other hand are not necessarily compostable. They will degrade over time but are not suitable for your compost heap or any other compost heap for that matter. In fact, technically fossil fuel-based plastics are biodegradable in the sense that they will eventually break down with the help of microorganisms out in nature. However, this can take hundreds of years and leave toxic residue behind. And the same goes for biodegradable plastics.
Pros and cons of biodegradable plastic
Pros
- Can be plant-based and recyclable
- Can break down more easily than conventional plastics
- Some are non-toxic
- Some are compostable
- Can play a key role in waste management
Cons
- Can be just as toxic as conventional plastics
- Can lead to waste stream contamination both in terms of composting and recycling due to confusion
- Can become ocean litter
- Requires more resources in the form of crops and agricultural inputs
- Don’t really add any value to compost when they are compostable
What's the difference between actual compostable and biodegradable products?
When it comes to the difference between actually compostable and biodegradable products, the main thing to remember is that biodegradable does not equal compostable. In fact, as we’ve discussed here, compostable does not always mean compostable either. Especially if you are composting at home.
Biodegradable vs compostable coffee cups
Biodegradable coffee cups must be sent to the landfill unless otherwise indicated on the packaging. On the other hand, compostable coffee cups could be sent to commercial composting operations or composted at home where applicable. Again it’s important to check the packaging to see what applies to the product in question because some products are not designed to break down in home composting systems, and some commercial operations do not accept certain compostable products. Remember to look for reputable certifications from organizations like FTC and BPI.
Compostable plastics
Compostable plastics are made from plants rather than petroleum. And just like there are different types of plastics, there are different types of compostable plastics. They can be designed to be commercially compostable or home compostable. If you are composting to make worm tea or apartment composting it’s not likely you’ll want any bio-based plastics in the mix.
They can also be engineered to be structurally identical to fossil fuel-based plastics which means they can go on to pollute and last in the environment just like conventional plastics do. Some bio-based products can be recycled but again it is important to consult the product's label to make sure.
Bottom line when it comes to Biodegradable vs Compostable
Biodegradable and compostable products are not the answer to our dependence on disposable things. It’s important to use caution and to consider reusables like the ones among these 12 easy zero waste swaps. It may seem difficult and inconvenient at times but this is the best way to make sure we are actually diverting waste from the landfill. So instead of reaching for a compostable cup try bringing your own reusable coffee cup or an eco-friendly water bottle instead.
For any more sustainable living essentials be sure to drop by the brand directory. You will find home goods, plastic-free zero waste goods, green beauty brands, natural cleaning products, shoes, and much more. And thank you for trying to do your part to reduce your environmental footprint.
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