We've been conducting R&D into home compostable packaging for over 4 years. We've learnt a lot along the way and developed a finely tuned greenwashing radar. We've visited our production facilities and verified in person that what is being used to make our bags, is what it's meant to be. We now know more about certification numbers, authorising bodies and even bag thicknesses than we ever thought possible! We even own a micrometer ...

Here's what we've learnt that you need to look for when purchasing compostable packaging;

1. A certification symbol WITH A NUMBER
2. That the certification is valid for the thickness of the packaging


The number associated with a certification symbol is the key to identifying it as legitimate as this is how the material can be verified. The Australasian Bioplastics Association (ABA) guidelines state that when a product is claiming certification, it must also have the ABA number otherwise there's no way to trace what it is made of and therefore whether or not it's legitimate. A bag without a number is a bit like a vehicle licence plate with nothing on it!


There are no certification numbers accompanying any of the certifications this bag claims to have: AS 5810 Home, AS 4736 Industrially, and OK Home Compost.



As you'd imagine, the thicker a material is, the longer it takes to biodegrade in a compost. To gain a home compostable certification, a material must break down within a certain timeframe. This is why compostability certifications always specify the maximum thickness a material can be to still meet the criteria required for that certification.


Listing on the Australasian Bioplastics website for the ABAP 20004 compostability certification - valid to 43um


Listing on the TUV Austria website for the S0335 OK Home compostability certification - valid to 36um


This courier satchel displays the S0335 certification number so should be no more than 36um thick, however it is 67um thick, over 50% thicker than permitted to be home compostable


In our experience, it is not possible to produce a mailer with material less than 50um thick - the seams won't hold.


This courier satchel displays the ABAP 20004 certification number so should be no more than 43um thick, however it is 67um thick, over 50% thicker than permitted to be home compostable


Here's a link to the Australasian Bioplastics Association and TUV Austria (OK Compost) where you can see all the certifications and their maximum thicknesses. We strongly encourage you to do your research.



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