Over the past few years, biodegradable bags have become a retailer’s best friend but are they really as eco-friendly as we’re led to believe? Just how long do biodegradable bags take to decompose?
Under the right conditions, biodegradable bags will fully decompose between 3 to 6 months. Temperature and moisture are examples of conditions that affect the duration and in fact, decomposition cannot take place in certain environments such as the ocean.
My research into this topic uncovered a good few surprises so let’s get into it.
Before we do if you are interested in finding out whether biodegradable bags are actually biodegradable then it’s worth reading my earlier article which can be found here: “Are Biodegradable Garbage Bags Really Biodegradable?“
We can all agree plastic bags are one of the most serious threats to our environment. They are more prevalent in our daily lives than almost any other object and continue to be found in the remotest of areas of our planet.
So common are these types of bags that still now when we go to the supermarket or a convenience store to buy our groceries we will always be asked if we want a plastic bag.
In the majority of cases, we are not able to influence the type of plastic that is used for packaging our products, That said you probably already know that there are now various alternatives to the classic plastic rubbish bags, and in recent years some retailers have switched to selling what is termed biodegradable bags.
A good move you may ask – well let’s see.
Alternatives to Classic Plastic Garbage Bags
“Compostable” and “biodegradable” bags are frequently touted as environmentally friendly alternatives.
While the terms may appear to be interchangeable, they are not.
If a bag is “biodegradable”, it means that it will gradually break down with the help of biological helpers such as bacteria or fungi if left in a completely natural environment.
Whilst all things biodegradable might seem the solution to our global problems, the word doesn’t specify how long this process takes and so can be quite misleading when it comes to how eco-friendly an object is.
If a bag is “compostable”, it suggests that it will decompose in a very particular set of conditions within a specific amount of time, leaving no hazardous residue in the environment. While this phrase or label could be considered equally ambiguous compostable items are generally thought of as eco-friendly.
It should be noted that compostable bags are typically manufactured from plants such as corn or potatoes.
How Do Biodegradable Bags Decompose?
One thing I did discover whilst carrying out my research is that biodegradable bags are essentially broken down by natural creatures such as fungi, bacteria, and microorganisms
However for the creatures to do their magic the whole process needs specific environmental conditions to do so. High temperature is one of those conditions which is difficult to achieve across the globe.
For example, the ocean is one environment where biodegradable plastics cannot degrade.
This is why you may come across biodegradable-labeled bags floating around in the ocean still in their original form.
Surprisingly not all biodegradable plastics break down in landfills either.
Interestingly there are a few types of biodegradable rubbish bags on the market and so it’s important to keep a look out for rubbish bags that clearly states ‘landfill-biodegradable’.
Processing Biodegradable Garbage Bags
As biodegradable rubbish bags need certain environmental conditions to degrade it’s not always possible to dispose of them correctly, especially in the cooler parts of the world.
For decomposition to take place specialized industrial composting and recycling facilities that can heat the bioplastic to a high enough temperature to cause it to degrade are required.
Furthermore, bioplastics and recycled plastic must be separated because if bioplastic contaminates traditional plastic, the entire batch may be rejected and disposed of in a landfill.
The degradation of biodegradable polymers is certainly a complicated process, and we’re still unprepared for it.
At the time of writing this article, the UK has only 170 facilities capable of recycling bioplastics, while the US has 185.
While bioplastics have advantages, we must improve our recycling infrastructure in order to reap the benefits.
How to Make a BioPlastic Bag
Just as a bit of fun here is a video I came across whilst researching biodegradable bags – turns out you can make your own bioplastic bags with just a few different materials you can find around the house.
Biodegradable plastics degrade completely in three to six months. That is far faster than synthetic alternatives, which take hundreds of years.
The length of time it takes for a biodegradable bag to degrade is determined by several factors, including temperature and moisture content however, these types of bags aren’t always as eco-friendly as they appear.
They’re created from petrochemical-based polymers that are comparable to normal plastic, but with components added that cause them to progressively dissolve in the presence of light or oxygen.
Bioplastics derived from cornstarch and other plant-based components are a superior option.
They emit CO2 as they degrade, but this is simply carbon released from the plant matter that created them.
As a result, the net environmental impact is close to zero.
Wherever possible it’s always better to use compostable bags than biodegradable ones.