Less Hazardous Chemical Synthesis

The third principle calls for chemical reactions and synthesis routes to be designed to be as safe as possible, so that the formation of hazardous waste is avoided wherever a process can be redesigned to do so. The chapter's illustrating case is the insecticide DDT (dichlorodiphenyl trichloroethane), once widely used and genuinely effective at controlling the mosquitoes that spread diseases such as typhoid and malaria, but later recognised to be harmful to living things generally, not just to the insects it targeted. In its place, benzene hexachloride (BHC) is used as a modern insecticide; one particular isomer of BHC, its gamma (y) isomer, is specifically known as gammexane or lindane. The example illustrates the principle directly: rather than continuing to use an effective but broadly harmful chemical (DDT), gree …