Proponents of a "lean is green" relationship provide several arguments (Florida 1996; Hart 1997). For one, the adoption of lean practices may lead inadvertently to pollution reduction. Some proponents observe that "zero waste" is the mantra of lean production and suggest that pollution reduction will inevitably follow from lean production. Critics point out, however, that reducing one factor of production may increase another. Efforts to increase the efficiency of throughputs may lead to a greater production of waste. Reducing inventory, for example, may lead to a greater production of waste. The small batch size production inherent in lean production entails more frequent changeovers, and these changeovers might require cleaning of production equipment and disposal of unused process material.