Green chemistry refers to a number of processes and practices that minimize the toxic or hazardous effects of chemicals in the environment, the lab, or the manufacturing plant. One way to go green is to cut down on the use of dangerous solvents in reactive processes, thereby reducing waste and improving lab safety. Though sometimes a less toxic catalyst or reagent can be employed from the outset, reused, or made inert eventually, another way to get a chemical reaction is to apply physical force instead. Called mechanochemistry, it involves the application of mechanical engineering to chemistry. Instead of adding a solvent, agitation is used to achieve chemical synthesis.