10. Design for degradation. Back in the olden days, really you wanted materials to last forever, but now we've learned through various experiences, most recently being the one concerning microplastics, you may not want the material to last forever, and you want it to degrade. Biodegradation is a very important aspect of the principles of green chemistry, and we're designing the material. We know what type of moieties within the structure tend to be susceptible to attack by microorganisms. So by design, we build those moieties into the molecule to make it more susceptible to degradation down the road.