Chemists are adopting benign-by-design strategies in order to reduce the impact of drugs on the environment once they pass through bodies and drained. Klaus Kümmerer, chemist, University of Freiburg Medical Center, suggests that medicinal chemists should avoid quaternary carbons because they disrupt biodegradability by microorganisms. He explains that sometimes during synthesis, medicinal chemists add moieties such as blocking groups that ends up in the final structure but not required for activity so it can be removed if they are found to be problematic for the environment. Berkeley W. Cue Jr., a consultant for the pharmaceutical industry explains that one way to reduce a drug's impact on the environment is to increase its oral availability so it does not pass so easily through the body. Cue suggests that excipients or additives can be designed in such a way that helps drugs to remain stable until they reach the environment.