Compostable haste makes waste
Most compostable bags and packaging will end up at the dump, just like plastic bags, due to a lack of facilities to process them.
Some companies, such as The Warehouse and Farro Fresh, are replacing plastic bags with compostable bags to reduce plastic waste.
However, The Packaging Forum spokeswoman Lyn Mayes said making that switch was swapping one problem for another, as New Zealand had just 11 facilities that accepted compostable packaging.
In addition, none of the facilities were big enough to process large quantities, meaning compostable waste from major events would probably end up in landfill, she said.
Compostable waste was ‘‘no different from plastic’’ if it became litter, she said.
‘‘If it ends up in the ocean … unless you are in the Dead Sea, I don’t think it’s going to break down.
‘‘If it’s a litter item, it’s a litter item. It doesn’t matter if it’s a compostable bag or a plastic bag.’’
Compostable bags are generally made from PLA, or polylactic acid, which is a biodegradable material derived from renewable resources such as corn starch, cassava roots, chips or starch or sugar cane.
Compostable packaging would be an ‘‘excellent solution’’ if New Zealand had enough facilities to take it, Mayes said.
Companies selling compostable packaging or bags needed to provide organic waste bins so customers could return their waste. The bins would need to be picked up by one of the 11 commercial composting companies, Mayes said.
If compostable waste was put in kerbside composting bins or soft plastic recycling bins, it would end up in landfill.
If it was put in home compost bins, it was unlikely to break down, as compostable packaging and bags only decompose if completely buried in temperatures above 60 degrees Celsius.
The composting facilities were not expandable at the moment, so they would probably struggle to keep up with demand, Mayes said. ‘‘We can do it on a small scale, but not on a large scale.’’
A working group has been established to figure out how to fix the issue of compostable waste.
The Compostable Packaging Standard Adoption Working Group (CPSAWG) will find out what types of compostable packaging there are, and will look at international standards before recommending one for New Zealand to adopt.
The working group is made up of composters, manufacturers, the waste industry, central and local government and research institutions.