Biodegradable vs. Compostable: What is the Difference?

Organic, vegan, cruelty-free, clean, reusable, biodegradable, compostable, the list of eco-friendly indicators is ever-growing - so much so that we often end up using them interchangeably. 

However, to lead a sustainable lifestyle, it’s important to go beyond the labels to understand what each tag really means. As always, we’re here to clear the air and share all the information you need to live in the most eco-conscious way.

So far, most of our previous blogs have focused on organic and reusable items. But today, the spotlight’s on ‘biodegradables’ and ‘compostables’ - from what they mean to their differences as well as similarities. It’s all here!

What are Biodegradables?

Here’s the thing - Almost every item on the planet, including some types of plastic, has the potential to break down and go back to nature. It boils down to how long they take to decompose and whether they release any pollution or toxic elements in the process. 

There are two types of biodegradation:

1. aerobic (with oxygen) and
2. anaerobic (without free oxygen).

The degradation that takes place in the presence of a good supply of oxygen is more earth-friendly as it takes lesser time.

Biodegradation rates vary dramatically. While fruits and vegetables take only days or weeks to degrade, a plastic bottle may still be around even 400 years after it has been disposed of.

That’s why materials like plastic, styrofoam, and aluminum are considered non-biodegradable, as they take incredibly long to disintegrate. 

However, for something to be classified as ‘biodegradable,’ it must be natural to start with and decompose, leaving behind only organic matter, such as carbon dioxide, water, and minerals.

The biodegradation process is entirely natural and takes place with the help of microorganisms.

What are Compostables?

All compostables are also biodegradables, while the opposite doesn’t hold. The key difference is that while biodegradation occurs independently, composting requires specific conditions.

Composting is more of a human-controlled process to recycle organic matter for reuse. When done correctly, organic waste disintegrates into nutrient-rich soil with the help of oxygen, bacteria, and fungi. This humus-rich soil is then used as a fertilizer in gardening, agriculture, horticulture, and organic farming.

You don’t need sophisticated infrastructure to carry out this process, as it can be easily done at home. However, some compostable items are trickier to decompose, requiring commercial facilities to disintegrate. More on that later.

How Are Biodegradables Different from Compostables?

By now, you would have a fair idea of what these terms represent. While every compostable is also biodegradable, the opposite is not true. So, what makes some biodegradables different from compostables? Scroll down to find out.

• Human-Driven: Biodegradation is a natural process that doesn’t require any human assistance. You can leave fruit on a kitchen counter and watch it decompose in a matter of days. On the other hand, compostables need a human-controlled environment with the right balance of oxygen, temperature, moisture, and microorganisms.
  
  
• Time to Decompose: Depending on the type of waste and method applied, compostables may take anywhere between six months to two years to turn into soil. However, letting the compost mature is a good idea to increase its quality and stability.
  
  Biodegradables like food items take days to a few weeks to degrade, while cotton t-shirts may take six months to break down. There’s also something called plant-based biodegradable plastic, marketed with the claim that it takes only three to six months to break down. However, a study showed that shopping bags made from this material were intact even three years after disposal.

• Reusability: Biodegradables that don’t qualify for composting disintegrate slowly to release water, carbon dioxide, and methane. In other words, a fully decomposed item produces nothing tangible to reuse. 

On the other hand, in addition to water, carbon dioxide, and methane, compostables also yield biomass and humus, which are reused as fertilizer. 

Related Article: Upcycling vs Recycling: Which is Better For Planet Earth?

Are Products Labeled Compostable and Biodegradable Eco-Friendly?

Most items that carry these labels are environmentally friendly, but just how good they are for the planet depends on how they’re processed. For degradation to happen quickly and successfully, oxygen is a key ingredient.

Suppose a biodegradable or compostable item is stuck under piles of trash in a landfill. In that case, it may take way longer to decompose than if it was in a more conducive environment. A good supply of oxygen, microbes, and light does wonders in accelerating the decomposition rate.

Two Major Types of Composting

Composting is a controlled decomposition that needs the right mix of nitrogen-rich ‘green’ waste (think grass clippings, food scraps) and carbon-rich ‘brown’ waste (dry leaves, wood chips, twigs). It also requires optimal moisture content, oxygen flow, and temperature for microorganisms to thrive and do their job. 

Composting can either take place at home or in a commercial facility.

• Residential Composting: When you compost at home, you need to combine food scraps with yard waste in a bin - a good mix now and then helps speed up the process.

  This type of composting is ideal for small quantities of food waste except for animal products like fish and poultry. ‘Bokashi’ is a popular method to compost food scraps through fermentation.

• Commercial Composting: Industrial composting is more suited for complex compostables like bags and packaging and large quantities of food waste. Material is sorted into organics and inorganics and broken down using industrial equipment. The next step involves the creation of the proper environment to support the composting process. Windrow, Vermicomposting, Static Pile, and In-Vessel composting are the most widely used commercial composting techniques.

Starter Kit Essentials For Home Composters

Like recycling, composting is crucial for zero-waste living. It’s a way of recycling organic waste and reusing it. What’s great is that you can easily do it at home with a few items. Here’s what you’ll need besides the mix of greens and browns to get started:

Compost Culture: You can either wait for nature to kickstart composting or add compost microbes to speed up the process. Not only do they accelerate composting, but they also improve the quality of compost by retaining nutrients. These bio-organic starters are readily available online.

Compost Bin: Your compost pile needs a place to decompose. It doesn’t have to be an expensive purchase, and you can simply use a large-sized spare container in your home.

It’ll help if you get hold of something easy to turn or rotate. Because giving the contents a good shake now and then keeps the odor at bay and makes it stable. Here are some bin ideas - plastic buckets, plastic storage containers, and trash cans.

Bulking Agent: Carbon-rich bulk in the form of sawdust, wood chips, rice bran, cardboard, and leaves are mixed with nitrogen-dense food waste to maintain a balance of carbon and nitrogen during composting. You only need these if you don’t have enough ‘browns’ or yard waste at home.

Gloves: You cannot do without gloves, as compost piles are usually packed with bacteria and fungi. Any reliable pair of washable, earth-friendly gloves would work for composting duties.

Check Certifications to Avoid Greenwashing

According to the US Composting Council, a compostable product is any product manufactured specifically to break down in a compost system at the end of its useful life - for instance, bags, coffee pods, and take-out containers.

Green labels are often misleading, and it’s essential to check the authenticity of such claims by checking if the product is certified as ‘compostable.’ In North America, the compostability of a product is verified and approved by the BPI (Biodegradable Products Institute). 

For a BPI certification mark, a product must undergo rigorous testing to check if it can break down when mixed with food and yard waste without impacting compost quality.

Popular Compostables

There are over 10,000 compostables that have been certified by BPI. They maintain a list of approved products that you can check before buying. Here are some of the most popular types of compostables out there.

Compostable Trash Bags: BPI-certified bin liners and bags are an excellent alternative to plastic trash bags. These bags easily break down into the water, carbon dioxide, and humus.  

Compostable Packaging: Foodservice industry still relies heavily on plastics for packaging and delivery. The BPI-approved catalog includes compostable check-out bags, produce bags, food prep gloves, and sandwich wraps, among other types of packaging.

Compostable Cutlery: Plant-based cutlery, such as those made with all-natural corn, can be composted at industrial facilities at the end of its useful life.

Related Article: Your Ultimate Guide to Live a Zero Waste Lifestyle.

Don’t Forget Minimizing Waste, Recycling, and Reusing

Hundreds of products are being specifically manufactured to be ‘biodegradable’ and ‘compostable.’ While they’re still better than harmful plastics, if these products are designed for single-use, they aren’t good news for the planet.

Why? Because not everyone is into home composting or has access to commercial composting sites. You can’t even put these products in recycling piles as they can contaminate other recyclable items during degradation. 

Instead, we should opt for reusables that stay in the consumer cycle for a long time and can be recycled at the end of their shelf life. For instance, go for reusable grocery bags instead of single-use biodegradables or compostable alternatives.