Phosphate-free automatic dishwashing detergents — introduced to combat the phosphate-fed algae blooms that foul the nation’s lakes and rivers — may be making the fish happy. But they’re putting a frown on the faces of some consumers who say the new products leave dishes dirty. That’s the topic of the cover story in the current edition of Chemical & Engineering News (C&EN), ACS’ weekly newsmagazine.
C&EN Assistant Managing Editor Michael McCoy described how new laws in 16 states require manufacturers to eliminate phosphates from automatic dishwasher detergents sold in the United States. Once hailed as a wonder for making dishes squeaky clean, sodium tripolyphosphate later became a villain in the fight against water pollution. It can wash down household drains, through sewage treatment facilities, and into lakes and streams. Just like the phosphate fertilizer applied to crops, it kick-starts growth of algae, which die, decay, and deplete oxygen from the water, causing fish kills and other problems. McCoy explains that the well-intentioned phosphate-removal laws, however, have caused an unintended problem for some consumers, leaving dishes and glassware with spots and unsightly films.
Detergent manufacturers are now turning to chemists and the chemical industry in a search for phosphate-free formulas that don’t leave dishes dirty. Some manufacturers have already found promising alternatives, while others are testing new detergent ingredients, including polymers and enzymes, that can clean like phosphates without contributing to water pollution.