Volume 88 Issue 4 | Web Exclusive
Issue Date: January 25, 2010

Cover Stories: Beyond The Basics

Phosphate Phaseout Is Opportunity For Chemical Suppliers

Department: Business
News Channels: Environmental SCENE
Keywords: detergents, Paint, surfactants, Phosphate
Credit: Michael McCoy/C&EN
Credit: Michael McCoy/C&EN

On July 1, everything changes for U.S. manufacturers of automatic dishwasher detergents (ADDs). That's when bans on phosphates in ADDs go into effect in about 15 states. And because of the realities of distributing products to today's chain stores, the ban is effectively kicking in nationwide.

Accused of contributing to eutrophication in lakes and rivers, phosphates were eliminated from laundry detergents in the early 1970s. However, the cleaning products industry lobbied to keep them in ADDs because of their crucial role in those products. Susan O. Baba, external relations manger for Procter & Gamble's home care business, explains that phosphates perform almost all the roles expected of an ADD, including pH maintenance, food and grease removal, and suspension of insoluble dirt in the wash water.

Now phosphates are going out, and much more quickly than the cleaning products industry's researchers would like. Replacing them "has been a large challenge for our technical community," Baba says.

It's also a large opportunity for chemical companies, which are clamoring to come up with chemistry that replaces phosphates effectively and economically. The opportunity is larger than just the U.S., because proposals to ban phosphates in ADDs are starting to pop up in Europe as well.

Likening phosphates to the flour in a cake, Baba says no one product is going to replace them. "There's no good proxy for flour," she says. "It takes a bunch of other ingredients to replicate what that one ingredient does."

Nilesh Shah, global R&D director for Dow Chemical's home and personal care business, says his firm's Acusol 425N is an early winner in the replacement game. A water-soluble acrylic dispersant touted as enabling phosphatelike cleaning in a phosphate-free formulation, Acusol 425N was developed a number of years ago by Rohm and Haas, but it languished on the company's shelves in the absence of antiphosphate legislation.

That has now changed. "Most of the large brand owners are gravitating to it," Shah says. "It's also happening in Europe, and we're seeing interest in Brazil and China."

Clariant is positioning its SKS-6, a layered sodium silicate, as an ingredient that does much of what phosphates do, but at lower volumes, says Manfred Trautmann, vice president of the firm's detergents and intermediates unit. The firm also markets a bleach activator, tetraacetylethylenediamine, that is combined with sodium percarbonate bleach for phosphate-free ADD formulas.

BASF has its own entry in the phosphate replacement game, says Gary Dee, director of the firm's North American home and personal care chemicals business: the trisodium salt of methylglycinediacetic acid, trade-named Trilon M by BASF. A chelating agent, it allows formulators to make phosphate-free ADD gels that perform as well as phosphate-containing powders, Dee says. The performance gap has been particularly hard to close in phosphate-free gels, he notes, because they are water-based and compatible with a more limited palette of ingredients than are powders.

P&G may be realizing this performance gap already with its Cascade with Dawn Gel. Although the ban has yet to kick in widely, the company took phosphates out of the product about six months ago, Baba says, so that it can be sold in parts of Washington state that already ban phosphates.

P&G's website for Cascade allows consumers to comment on its products. Although most Cascade products rate highly, the new Cascade with Dawn Gel gets surprisingly low marks. Baba attributes this to regional differences in water hardness that affect gel ADDs more than powders. That may be so, but Cascade Complete Gel, a different product that still contains phosphates, gets much more favorable ratings from consumers.

Another difference between Cascade with Dawn Gel and other versions of Cascade is the absence of enzymes. Baba says Cascade with Dawn Gel is formulated with bleach instead. "We will continue to utilize multiple enzymes in the majority of our automatic dishwashing detergents to deliver the great cleaning and shine that our customers expect from Cascade," she says.

Chemical & Engineering News
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