This dataset contains a range of measurements associated with the degradation of Polylactic acid (PLA)-cellulose based teabags, buried in soil. Degradation measurements were calculated following a 7-month burial period from November 2021 to June 2022. Variables measured include: mass change, mass change of PLA, crystallinity change, and pyrolysis gas chromatography-Mass spectroscopy (GCMS) data for each teabag type. This research is part of the BIO-PLASTIC-RISK project, funded by Natural Environment Research Council through the grants NE/V007556/1 and NE/V007246/1.