Some longtime users were furious.

"My dishes were dirtier than before they were washed," one wrote last week in the review section of the website for the Cascade line of dishwasher detergents. "It was horrible, and I won’t buy it again."

"This is the worst product ever made for use as a dishwashing detergent!" another consumer wrote.

Like every other major detergent for automatic dishwashers, Procter & Gamble’s Cascade line recently underwent a makeover. Responding to laws that went into effect in 17 states in July, the nation’s detergent makers reformulated their products to reduce what had been the crucial ingredient, phosphates, to just a trace.

While phosphates help prevent dishes from spotting in the wash cycle, they have long ended up in lakes and reservoirs, stimulating algae growth that deprives other plants and fish of oxygen.

Yet now, with the content reduced, many consumers are finding the new formulas as appealing as low-flow showers, underscoring the tradeoffs that people often face today in a more environmentally conscious marketplace. From hybrid cars to solar panels, environmentally friendly alternatives can cost more. They can be less convenient, like toting cloth sacks or canteens rather than plastic bags or bottled water. And they can prove less effective, like some of the new cleaning products.

"Most Americans want to do things that are good for the environment, but not everyone wants to pay the price," said Elke U. Weber, director of the Center for Research on Environmental Decisions at Columbia University.

In the world of cleaning agents, where chemicals and fragrances can pose respiratory and allergy problems as well as pollute waterways, the environmental benefits of the switch are clear. Yet the new products can run up against longtime habits and even cultural concepts of cleanliness.

Phosphorus in the form of phosphates suspends particles so they do not stick to dishes and softens water to allow suds to form.

Now that the content in dishwasher detergent has plummeted to 0.5 percent from as high as 8.7 percent, many consumers are noticing the change in the wash cycle as they run out of the old product.

"Low-phosphate dish detergents are a waste of my money," said Thena Reynolds, a 55-year-old homemaker from Van Zandt County, Texas, who said she ran her dishwasher twice a day for a family of five. Now she has to do a quick wash of the dishes before she puts them in the dishwasher to make sure they come out clean, she said. "If I’m using more water and detergent, is that saving anything?" Reynolds said. "There has to be a happy medium somewhere."

Similarly, a nonprofit group in Oakland, Calif., that helps women form environmentally minded cooperatives and trains house cleaners, says their employers have often resisted switching to the new cleaning products.

"There’s the myth that to be clean it has to shine or smell or make a lot of bubbles," said Ivette Melendez, one of the trainers for the group, Women’s Action to Gain Economic Security. She says products like vinegar, baking soda or the newer cleansers work just as well as traditional items if applied in the proper mix and quantities.

But Jessica Fischburg, a commerce manager in Norwich, Conn., for CleaningProductsWorld.com, which sells janitorial supplies in bulk, said she was not surprised that many of her clients rejected products marketed as environmentally friendly.

"The reality of any green product is that they generally don’t work as well," she said. "Our customers really don’t like them."

But some users attest to quantifiable benefits. Reports of burns, rashes, dizziness and scratchy throats among housekeeping employees have plummeted at North Central Bronx Hospital and Jacobi Medical Center since the staff switched to new cleaning products in 2004, said Peter Lucey, an associate executive director for support services at the New York City Health and Hospitals Corp. The number of lost days linked to injuries from the products declined from 54 in 2004 to zero last year, he said. "It’s the switch and the training," Lucey said.

In the case of the new dishwasher detergents, the main benefit is viewed as the protection of bodies of freshwater.

Once they go down the drain and into the environment through discharge at sewage treatment plants, phosphates end up in lakes, streams and drinking-water reservoirs.

Phosphorus pollution comes from multiple sources, including fertilizer and manure that enter the water through runoff. Dishwasher detergents contribute just a fraction, but environmental campaigners say any reduction can result in a tangible improvements. (Laundry detergents and hand soaps are already free of phosphates.)

The first significant regulatory rumblings came in Washington state in 2006. As more and more states followed suit, manufacturers faced the prospect of uneven laws that could disrupt retail distribution nationwide, said Dennis Griesing, vice president for government affairs at the American Cleaning Institute, which represents the cleaning product industry. The nationwide product rollover began late last year.

Industry officials generally insist that most customers have not noticed a change. But in its September issue, Consumer Reports reported that of 24 low- or phosphate-free dishwasher detergents it tested, including those from environmentally friendly product lines that have been on the market for years, none matched the performance of products with phosphates.

The magazine did note that the formulas were improving, and it rated seven detergents "very good," including two of six Cascade products it tested. Susan Baba, a spokeswoman for Cascade, said that while most Cascade customers had not noticed any change, Procter & Gamble was modifying the formulas of some products in response to complaints.

"As we learn more, we’re finding out that there’s a lot more variation than we saw in the labs," she said.

Baba added that the conversion to low-phosphate content had been complex, with three or four ingredients needed to match what the phosphates accomplished alone.

Elise Jones, a 32-year-old mother of two in Chatham, N.J., and a blog editor for Babybites, a group for new and expectant mothers, said she noticed "a white dusty film" on her dishes and children’s cups starting about a month ago. "I thought it was the dishwasher," she said, before she heard of the change in formulas.

All the same, she agrees with the restrictions on phosphates because "we all worry about our water supply."

Washing the dishes entirely by hand is not necessarily better for the environment, experts say, because people tend to let the tap run even when they are not rinsing. So Jones now rinses them all by hand after the wash cycle, trying to economize on water so that her rinsing can match the dishwasher’s efficiency.

"You try to do things as consciously as you can," she said.

© 2010 The New York Times Company