Description Like a good oxymoron? How about natural plastics? Metabolix is working to make biodegradable plastic products out of corn sugar and other natural products. Metabolix calls its product Mirel (that being easier to say than polyhydroxyalkanoates, or PHA). The Mirel natural plastics line is the priority, but Metabolix is also developing a process to use switchgrass to co-produce PHA and a biomass feedstock to be used to make biofuels. Metabolix tested switchgrass as a feedstock in commercial trials during 2010. A joint venture with Archer-Daniels-Midland called Telles manufactures Mirel; the partners constructed a manufacturing facility in Iowa, which has an annual production capacity of 110 million pounds of PHA.