The principle “Chemical products should be designed so that at the end of their function they do not persist in the environment and break down into innocuous degradation products”, that appears 10th in the original list of “Principles of Green Chemistry” (Fig. 1), published by Anastas and Warner,1 must remain part of the fundamental basis of green chemistry. Consider the definition of two key words: principle – “a primary assumption forming the basis of a chain of reasoning”2 and chemistry – “the branch of science concerned with the substances of which matter is composed, the investigation of their properties and reactions, and the use of such reactions to form new substances”. 3 Clearly any practitioner of chemistry that purports to be ‘green’, must consider the end fate of the substances that are created and endeavour to ensure that these ultimately “do no net harm” (to borrow from the Hippocratian tradition of modern medicine, as interpreted by Sokol4).