Is PLA biodegradable?
PLA is presumed to be, and is often called biodegradable, although the role of hydrolysis vs. enzymatic depolymerization in this process remains open to debate. Composting conditions are found only in industrial composting facilities where high temperature (above 60C), high relative humidity (RH), and 2/3 mixture of organic food based materials can be controlled in order to supply the correct amount of nutrients to promote chain hydrolysis. This is required to break down the polymer structure before microbial activity can break down the remaining material. If PLA does biodegrade, it does so very slowly. According to Elizabeth Royte, writing in Smithsonian, PLA may well break down into its constituent parts (carbon dioxide and water) within three months in a “controlled composting environment,” that is, an industrial composting facility heated to 60 degrees Celsius and fed a steady diet of digestive microbes. But it will take far longer in a compost bin, or in a landfill packed so tight
