Because of its ability to prevent unsightly scale by trapping water-hardening calcium and magnesium ions, phosphate is a chelating agent that has long been a valued component of dishwashing detergent. Chelating agents literally take a tight grip on calcium and magnesium ions, which would otherwise leave scale on washed dishes. But, as helpful as they are in getting your dishes clean, phosphates may have had a significant downside. They are important plant nutrients that, when present in large amounts in wastewater, encourage extreme algae growth, which in turn disrupts the ecological balance in lakes and rivers. Even though, since the 1980s, progressively stricter phosphate standards have been able to control this phenomenon, manufacturers continue to seek out an alternative.
And for anyone who thinks that washing dishes by hand is a better ecological alternative, Nancy Bock, Vice President of Consumer Education at the American Cleaning Institute®, points to a study conducted by the Institute of Household Technology of Bonn University. After taking a close look at people's dishwashing habits, the study observed that modern dishwashers now consume about 2.7 gallons of water and well below one kilowatt-hour of energy per wash cycle. These favorable consumption values are practically impossible to achieve when washing dishes by hand. In addition, most automatic dishwashers save about an hour's time per day, which adds up to almost 50 working days a year.