Dishwasher Spots Due to Phosphates

Phosphates

• Phosphates -- salts containing phosphorus and other minerals -- were used by manufacturers to improve the way dish soaps performed, and they served several functions. They helped control alkalinity, which made the cleaner more effective. They softened hard water, helped break large particles of dirt down into smaller particles, kept dirt particles suspended in solution so they couldn’t settle back on the dishes, helped break down grease, and made it easier to rinse the cleaner off the dishes after they were washed. However, according to the State of Washington Department of Ecology, automatic dishwasher detergent was also responsible for between 10 and 12 percent of the phosphorus found in municipal wastewater plants.

Damage

• Phosphorus in water speeds up the growth of algae and aquatic weeds and reduces the amount of oxygen that’s available to fish and other plants. High levels of phosphorus can be hard to remove from lake water that’s used as a drinking source. Extra chemicals may be needed, adding to the cost of treatment. In addition, algal growth can corrode pipes, clog intakes and affect the smell and the taste of the water. Swimming in water that contains a lot of algae is one reason people get “swimmer’s itch.”. In the 1950s and ‘60s, phosphates weren’t regulated and, by the late 1960s, almost 10,000 public lakes had been affected by phosphate pollution. Nationwide, detergents accounted for almost half the phosphorus found in wastewater during that time. In 1993, the federal government banned phosphates from laundry detergents, but the ban didn’t affect dishwasher detergents.

Bans

• Many states passed bans on the sale of high-phosphate detergents, but they delayed implementing the bans until July 1, 2010, to give manufacturers a chance to develop new products. Manufacturers agreed to a voluntary ban on phosphates in dishwasher detergents and their ban also went into effect on July 1, 2010, when members of the American Cleaning Council announced they would no longer use phosphates in their dishwasher detergent formulations. These bans apply to household automatic dishwasher detergents containing more than 0.5 percent phosphorus, not to commercial detergents, which are exempt.

Solutions

• Since the ban went into effect, consumers have complained that dishwasher detergents aren’t cleaning their dishes, which come out of their dishwashers covered with spots or a white film. This problem occurs more often in water with a high mineral content. Liquid rinse agents available for use in dishwashers are designed to help eliminate spotting. Alternately, use white vinegar to remove spots. Wash and rinse your dishes normally, then remove silverware and metal items. Put 2 cups of white vinegar in a glass on the bottom rack and run the dishwasher through a complete washing cycle again, but without using any detergent.