Compostable mailing bags offer a more sustainable alternative to traditional plastic packaging, helping reduce plastic waste across e-commerce, retail and food packaging operations. This guide explains what these mailing solutions are, what compostable bags are made of, how they break down, how to dispose of them correctly and whether or not they truly deliver environmental benefits.
What Are Compostable Bags?
Compostable bags are packaging products made from plant-based or biodegradable materials designed to break down into natural elements under composting conditions.
Unlike conventional plastic bags, which have the potential to persist for centuries, compostable mailing bags decompose without leaving harmful residues. They are commonly used for e-commerce mailing bags, food packaging, bin liners and retail shopping bags as a more sustainable packaging option.
What Are Compostable Bags Made Of?
What are compostable mailing bags made of is a question that is often asked. The answer will all depend on which option you choose but typically they are made from PLA, corn starch, sugar cane and other plant-based resources.
These materials replace the petroleum-based plastics and allow bags to break down naturally through microbial activity. During composting, they can transform into water, carbon dioxide and nutrient-rich compost without harmful residues.
Compostable vs Biodegradable Bags
Compostable and biodegradable bags both break down naturally, but the way they decompose is the key difference. Compostable bags are designed to break down within a specific timeframe under suitable composting conditions, leaving behind natural, non-toxic materials. Biodegradable bags can also degrade, but there is no guaranteed timeframe and some may leave harmful residues behind.
While both options are far more sustainable than traditional plastic, compostable mailing bags are generally considered the better environmental choice. For UK businesses and consumers alike, compostable bags offer a more responsible packaging solution, especially when disposed of through suitable composting facilities or applications.
How do compostable bags break down?
Compostable bags are designed to decompose naturally under the right conditions. When you place them into a composting environment with moisture, oxygen and microbial activity, the bags will undergo degradation.
Microorganisms will feed on the bag and break down its molecular structure. As the temperature rises within the compost and the bag fragments into smaller pieces, it will eventually transform into nutrient-rich compost. This is great for garden soil and promoting plant growth.
How Long Do Compostable Bags Take to Decompose?
Compostable and biodegradable bags both break down naturally, but the way they decompose is the key difference. Compostable bags are designed to break down within a specific timeframe under suitable composting conditions, leaving behind natural, non-toxic materials. Biodegradable bags can also degrade, but there is no specific, guaranteed timeframe and some may leave harmful residues behind.
While both options are far more sustainable than traditional plastic, compostable mailing bags are generally considered the better environmental choice. For UK businesses and consumers alike, compostable bags offer a more responsible packaging solution, especially when disposed of through suitable composting facilities or applications.
What happens if a compostable bag is thrown into a regular bin?
When a compostable bag is thrown into a regular bin and ends up in a landfill, its ability to break down is greatly hindered due to a few factors. Firstly, lack of oxygen. Compostable materials require oxygen to decompose properly through microbial activity. Without it, the decomposition process is slowed down and the bag may not break down as quickly or completely.
The second factor is low moisture. Landfills are often compact and covered in soil. Compostable materials need moisture to facilitate microbial activity once again, and without it the bag may remain intact for a longer period of time.
Lastly, methane production is a big problem. In anaerobic environments (like landfills), organic materials will decompose and produce methane – a potent greenhouse gas. While compostable materials will still break down without oxygen, the process will produce methane instead of carbon dioxide that can be stored – and will contribute to climate change.
Overall, when a compostable mailing bag ends up in the regular bin and therefore a landfill, it could take significantly longer for it to decompose compared to a proper compost environment.
So, where do we dispose of compostable bags? Industrial versus home
Annoyingly enough, disposing of compostable products is entirely local. Some areas of the word, (like the United States, for example), do not have the infrastructure for home composting – only industrial. Therefore, if you’re going to choose compostable bags for your products it’s important to know where your customers are located and if they have access to the proper disposal methods. Luckily here in the UK, home composting and industrial composting is widely practiced. Therefore, compostable bags may be the ideal solution for UK based consumers. But, knowing whether your compostable bag is home compostable or industrially compostable is extremely important.
Industrially compostable means that your compostable bag can ONLY be properly broken down in an industrial facility meant for composting. These tend to be located in every major city in the UK and practiced widely nationally. But this means that your compostable bag CANNOT go into your home composting bin.
Home compostable means that your compostable bag can go in EITHER home or industrial compost. It is able to have its conditions for composting met easier than industrial-only compost, and therefore will break down in either or – controlled or uncontrolled conditions.
Telling the difference between these two is extremely important to ensure proper decomposition, and there are many certifications to ensure that these conditions are met. Here at SR Mailing, we are proud to say that our compostable mailing bags are home compostable and industrially compostable. Let’s cover some of these popular certifications and what they mean.
Understanding Compostable Bag Certifications
One key aspect to verify is compostable certifications, which show that a product has been independently tested and meets recognised standards for breaking down safely into non-toxic material.
Our compostable mailing bags are certified to the following standards:
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TÜV AUSTRIA – OK Compost HOME
Confirms our bags are suitable for home composting and will break down into non-toxic material in approximately 6–12 months under home composting conditions. When disposing of compostable products at home, always look for the ‘OK Compost HOME’ logo rather than ‘Industrial Compost Only’. -
AS 5810 – Australian Home Composting Standard
Verifies that our bags meet Australia's recognised standard for home compostability. This certification confirms the material breaks down into non-toxic components, leaves minimal visible residue and supports healthy microbial activity. -
EN 13432 – European Compostability Standard
Confirms the materials used in our bags meet European requirements for compostability, primarily in industrial composting facilities where the materials will break down safely in a controlled environment.
TÜV AUSTRIA: Home compostable
TUV Austria is an internationally recognised inspection body that ensures our products were examined and verified through test samples of our products, and is able to bear the OK COMPOST HOME mark. In order to be certified, our product had to break down into non-toxic material in a home compost within a time frame of around 6-12 months.
The green HOME COMPOST sticker with the TUV Austria logo on it is important to look out for on compostable products so you can be sure of proper disposal, making sure it says HOME and not INDUSTRIAL ONLY before putting it in your home compost bin!
AS5810: Australian Standard for Biodegradability
Another widely accepted compost certification, ensuring conformity with the Australian Standard for home composting! This certificate also guarantees that our mailing bags will break down into non-toxic material within a timeframe of 6-12 months.
The material should disintegrate into fragments, with no more than 10% of the original mass remaining as residue visible to the naked eye after 12 weeks. The material must not contain any substances known to be harmful to human health or the environment, and should support microbial activity with a suitable substrate for microorganisms. By meeting these requirements, our compostable mailing bags demonstrate their ability for home composting once again!
EN13432: European Standard for Compostable Materials
EN13432 usually covers industrial composting as opposed to home composting, and this involves putting our product into a controlled commercial composting facility. However, our products were certified under EN13432 for compostable materials, ensuring that all the materials found in our compostable bags will break down properly in a composting environment.
Are compostable bags worth it?
As we look for more sustainable solutions, it is hard to say if compostable bags are completely “worth” it. It is entirely situational. In a country where composting is the norm, they are a great option if they are getting disposed of correctly. On the other hand, in places where the composting rate is rather low, it probably would not be best to use compostable bags – recycled paper or plastic will do just fine! But doing something is better than doing nothing.
That is why, we can conclude that compostables have the potential to be a great solution! *Depending on your situation*! In the meantime, it is important to stay informed as new sustainable solutions (like compostable) are formed, and making sure you can make the best (and most sustainable) solution for your business. If you feel compostable mailing bags may be a good option for your business, check our bags out! If compostable bags are not right for you, check out our recycled paper or recycled plastic bags instead!
Deciding whether compostable mailing bags are worth it all depends on how they will be used and eventually disposed of. Finding out how long do compostable bags take to decompose will give you a better indication of whether they are right for you. They are an excellent choice when customers have access to home or industrial composting, allowing the bags to break down into non-toxic material under the right conditions.
However, if composting facilities are limited and recycling is more widely available, recycled paper or recycled plastic packaging may be the more sustainable option. The best packaging is the one most likely to be disposed of correctly.
By considering your products, customers and local waste infrastructure, your business can choose the packaging solution that delivers the greatest environmental benefit.
FAQs
How long do compostable bags last?
Compostable mailing bags usually have a shelf life of around 6–12 months before use. To preserve their strength and quality, they should be stored in a dry, cool environment away from direct sunlight and excess moisture.
How are compostable bags made?
Compostable bags are produced using renewable materials like PLA, corn starch, sugar cane and other plant-based sources. These materials are processed into packaging that provides a sustainable alternative to traditional plastic bags.
Are biodegradable bags compostable?
Although biodegradable and compostable bags can both break down naturally, they are not the same and you may be asking “are biodegradable bags compostable?”. Compostable mailing bags have been designed to decompose into harmless materials under specific composting conditions, while biodegradable bags may not have.
Can compostable bags be recycled?
Typically, compostable bags are not suitable for standard plastic recycling because they can interfere with recycling processes. They should be disposed of through composting systems where they can break down correctly.
