Green chemistry reduces or eliminates the use or generation of hazardous substances from chemical products and processes. Green chemistry improves upon all types of chemical products and processes by reducing impacts on human health and the environment relative to competing technologies.

Green chemistry technologies encompass all types of chemical processes including syntheses, catalyses, reaction conditions, separations, analyses, and monitoring. A green chemistry technology can involve implementing incremental improvements at any stage. It can, for example, substitute a greener feedstock, reagent, catalyst, or solvent in an existing synthetic pathway. A green chemistry technology also can involve substituting an improved product or an entire synthetic pathway. Ideally, a green chemistry technology incorporates the principles of green chemistry at the earliest design stages of a new product or process. Benefits to human health and the environment may occur at any points in the technology's lifecycle: extraction, synthesis, use, and ultimate fate.