This lab lets a student determine and compare the amount of degradation of two types of plastic: degradable PLA (polylactic acid) and non-degradable plastics like PET (polyethylene terephthalate) and PE (polyethylene).  Students can vary the environmental conditions (type of plastic, temperature, humidity) and determine the time needed to degrade bottles of various plastics underground, and see the amount of degradation over time.  The lab is based on experimental data and related to an ILS on "plastic soup" (“Plastics en afbreekbaarheid”).  It illustrates that both the environmental conditions and the type of plastic have a large influence on the speed of degradation.