PLA’s Compostability Found Wanting


In New Zealand, researchers are challenging bioplastic producers’ claims of biodegradability.

Massey University’s Zero-Waste Academy and local government officials tested 47 products labeled as biodegradable to see if they did, in fact, break down after 6 months of composting. The products tested included plates, films, and utensils.

While disposable utensils made from polylactic acid were only barely degraded at the six-month mark, PLA films and bags disappeared quickly. Jonathan Hannon, the study’s lead, tells the Manawatu Standard this is likely due to the thickness of the utensils.

The study was also intended to instruct city council members on a planned organic waste collection program.  One council advisor, Nelson Lebo, lambasted PLA. “It’s worse than regular plastic. In municipal and backyard composting we can’t wait 18 months for something to break down,” he says. “We can break down bones in our compost heap, but not PLA. That’s how durable it is.”