Green : Cleaning technologies

Selecting environmentally safe metal cleaning alternatives requires a personal, careful, and comprehensive study. Before the days of depleting-the-ozone studies and volatile organic compound (VOC) regulations, the selection of a cleaning method for a particular metal process was simply tied to cost and result. Little, if any, consideration was given to the personal health of the operator or potential environmental impact. Nothing will ever be as simple as using methyl chloroform or other chlorinated solvents in a vapor degreaser. However, similar results can be achieved with greener technologies, provided that suitable procedures are followed. This article lists the questions to ask to properly evaluate current practices, explains the benefits and limitations of spray and immersion systems, describes environmentally benign aqueous and non-chlorinated solvent applications, and shows how to dispose of wastewater.