WIST now offers
compostability testing

A WIST technician monitors the biodegradability trial of the compostability test protocol.

A new testing service offered by WIST is aimed at meeting the growing demand within the bioplastics and packaging industries for certification of compostable materials.

WIST Executive Director Paul Fowler said that after several months of development and trial runs, the test is available commercially.

"It's a new service targeted at the compostable-packaging industry, to help them understand the biodegradability profile of their packaging and to establish whether or not the materials compost in line with accepted U.S. and European standards," Fowler said. "With that information, they may make certain claims regarding compostability in their marketing."

The October publication of revised Federal Trade Commission's Guides for the Use of Environmental Marketing Claims, the so-called "Green Guides," makes the launch of the new WIST service timely.

WIST's testing protocol follows the procedures of both US and European standards for compostability of plastic packaging. The protocol includes three stages: a disintegration trial, plant seed germination trial, and CO₂ evolution trial. It takes a minimum of 120 days to complete the full protocol.

A disintegration trial tests how well the material will break down in a stable composting environment. A plant germination trial determines how well the material will germinate seeds. Finally, in a biodegradability trial, the material being tested is placed in a sealed vessel, and instruments record the amount of CO₂ generated. The CO₂ is the product of decomposition and release of CO₂ is then compared to that of cellulose decomposition.

Kyle Herrman, assistant professor water resources, helped set up the testing protocol. Creating the system for the biodegradability test was the toughest obstacle to overcome, Herrman said. Constant monitoring of flow rates and CO₂ release is essential, and he and lab technicians worked to perfect the system so the equipment operated consistently and without any leakage.

Compostable packaging is becoming more important in the food industry. Packaging contaminated with food or composed of several different types of material is difficult to reuse or recycle. Compostability provides a useful end-of-life management solution. 

Only a handful of labs currently offer compostability testing in the U.S., Fowler said. With increasing demand for biodegradable packaging, WIST sees an opportunity to meet an industry need. "It's a natural fit for our laboratory capabilities and our goal of developing new, sustainable technologies," Fowler said.

For more information about WIST's compostability testing service, contact Fowler by phone at 715-346-3767 or by email at Paul.Fowler@uwsp.edu

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Students at UWSP sort PLA as part of a recycling project.

Dr. Adam R. Pawloski, Interfacial Solution's Technical Director, explains: "The challenge with recycling PLA is that its linear polymer chains are very susceptible to the process of hydrolysis, which breaks down the molecular weight of the polymer during reprocessing. This means that recycling PLA by conventional methods results in a plastic with degraded properties. Interfacial Solutions has developed proprietary process technology that 'hyperbranches' PLA polymers during reprocessing, restoring lost properties, and in many cases exceeding the properties of virgin PLA." 

With support from the UWSP College of Natural Resources and the College of Letters and Science