Polymers should not be (effectively) immortal. Yet, many approach that level of persistence when compared to the human time-scale. This has resulted in well-known concerns for plastics in landfills and in the oceans. It also is of concern for lesser-known issues such as the potential impacts of all of the micro- and/or water soluble synthetic plastics that due to their persistence are being integrated into ecosystems and the biosphere. Polymers can be designed such that their entire lifetime is approximately the same as their useful lifetime. Enduring and persisting beyond intended use serves little purpose and has been the cause of serious problems.