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. CERTIFICATION SYMBOLS & NUMBERS

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.

2. MATERIAL THICKNESS

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.