ABSTRACT
This chapter examines the basic question of what constitutes waste. It introduces successively various metrics based on the perspectives of waste production, input material consumption, and product formation. The common practice of material efficiency optimization is to take existing reactions regardless of how atom economical they are and to reduce Material Recovery Parameter as far as possible in an effort to reduce auxiliary material consumption. The great benefit of the technique is that there is a great saving in solvent consumption since work-up and purification are carried only out after the last chemical transformation has taken place. A strategy employed in organic synthesis that carries out more than one chemical transformation in a sequential fashion in the same reaction vessel without isolating the intermediate products generated after each transformation. In a balanced chemical equation, stoichiometric coefficients are the integer coefficients appearing before the chemical species.
