32WWW.CEN-ONLINE.ORG FEBRUARY 11, 2008

IT IS AN EVENT women tend to re-member. For me, it happened on a recent Sunday afternoon over an otherwise pleas-ant brunch with my best friend. Out of nowhere, she reached across the table and gleefully plucked a long, silvery strand from my head. It was that dreaded first gray hair.

Of course, my initial reaction to her dis-covery was to figure out how to hide it. Lucky for me, Procter & Gamble says it can make that step easier. The consumer products gi-ant just unveiled the first major innovation in hair coloring chemistry in more than half a century, a new process that promises to return my hair to its original state in just 10 minutes without all the damage and drying caused by conventional hair dye.

And while I’m not reaching for the dye just yet (I’m willing that first strand to be a fluke), doing so seems to be an inevitable rite of passage. According to P&G, roughly two-thirds of all American women will color their hair either at home or in a salon at some point in their lives. The market re-search firm Kline & Co. estimates the U.S. hair color market at about $2 billion per year at the manufacturer’s level.

Given the scads of home hair dye kits

populating the shelves at the local drug-store, it would seem safe to assume that different brands employ different science. And there has been a lot of incremental in-novation around colors that get consumers as close to, or as far away from, their origi-nal hue as they desire. Furthermore, new delivery systems enable the color to latch onto the hair better and for longer times, while conditioners help offset the harsh ef-fects of hair dye chemicals.

But the basic chemistry of the dyeing process hasn’t changed since the 1950s. A box of permanent hair dye is essentially nothing more than hydrogen peroxide, am-monia, dye precursors, and a surfactant. Mixing the peroxide and ammonia creates two reactive species—the perhydroxyl anion (HOO–) and the HO• radical—that raise the dye solution pH to somewhere between 10 and 11. The alkalinity causes

the hair fiber to swell and al-lows the dye precursors to penetrate.

The perhydroxyl anion then reacts with melanin pig-ment in the hair, lightens it, and simultaneously oxidizes the dye precursors, causing them to link and form the final color. The surfactant holds it all together, keeping the ammonia and dye precur-sors soluble in the peroxide, and provides some heft to keep the chemicals stuck to the hair while the process is under way.

Yet with a dye solution pH of 10 or 11, the coloring process is an exercise in brute force. The hair is inevitably damaged during the 30 min-

utes it takes for the dye to set—and then there’s the issue of the strong ammonia odor. What’s more, because of the toll it takes on the hair, dye should be applied only every four to six weeks.

THE HOME HAIR color market is growing at a modest 0.6% per year, in large part be-cause consumers—graying baby boomers in particular—have been turned off by the damaging effects of coloring, according to Carrie M. Mellage, director of Kline’s con-sumer products practice. She believes an innovation in the hair coloring arena could help companies regain the attention of women who have decided to “gray out.”

Consumers would “rather have some-thing that’s more like a beauty procedure than a chemistry lesson,” agrees Frauke Neuser, principal color scientist at P&G Beauty. “They want something that will keep their hair healthy and under good condition.”

P&G began looking into the problem in 1999, two years prior to acquiring Clairol and Wella, companies that brought P&G both hair color lines and a wealth of re-search expertise. P&G scientists’ first ap-proach was to focus on lowering the pH of the product to reduce damage to the hair. But the system they came up with couldn’t

COLOR CHALLENGEP&G banks on new HAIR COLORING chemistry

to reinvigorate a mature marketLISA M. JARVIS, C&EN NORTHEAST NEWS BUREAU

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Consumers would “rather have

something that’s more like a beauty

procedure than a chemistry lesson.”

33WWW.CEN-ONLINE.ORG FEBRUARY 11, 2008

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lighten the hair enough to produce the desired color, Neuser says, and the strategy was jettisoned.

A fresh perspective from scientists in P&G’s laundry and home care group, however, helped push the science forward. Though experts in removing tomato stains might not seem like the right people to solve a hair dye problem, the fundamental chemistry in both fields is similar. “We’re bleaching out melanin, they’re bleaching out stains,” says Jennifer Marsh, principal scientist in P&G’s beauty science division.

The researchers switched their focus to eliminating the HO• radical, a by-product of the reaction between hydrogen peroxide and metal ions. Because of the radical’s knack for damaging hair, the chemists thought getting rid of it would improve the performance of the product without sacri-ficing color.

“They came at it from a very different point of view,” Marsh says. “When you talk to laundry people, the first thing they tell you is you need to control the radical chemistry.”

The free-radical approach worked. Near-ly 10 years after the project began, P&G has devised a new hair dye chemistry system. The product was launched last month in select markets as Nice & Easy’s Perfect 10, named for the short time it takes to set.

The new system uses ammonium car-bonate, hydrogen peroxide, and the amino acid sodium glycinate, all of which react to form a different pair of reactive species: a peroxymonocarbonate ion (HCO4

–) and a carbonate radical (CO3

•–). Though some ammonia is still formed in the process, the peroxymonocarbonate ion permits the

bleaching and coloring to occur at pH 9, causing less damage to the hair. The hair is further protected by the addition of sodium glycinate, a radical scavenger that removes carbonate radicals as they’re formed.

THE INITIAL product launch includes 15 shades, a range that limits the line to home coloring, since salons expect the systems they buy to offer a palette of up to 200 shades. P&G plans to slowly bulk up the line, though the scientists say creating new colors has turned out to be more challeng-ing than anticipated.

“We learned the hard way how to com-pose colors and shades,” Neuser says. She notes that creating a new shade under stan-dard hair dyeing chemistry—say a blond that is between two existing shades—usu-ally involves about four to six iterations in the lab. P&G went through around 10,000

shade iterations to get just the 15 colors in the new product line. “The whole chemistry is dif-ferent,” Neuser says.

With the initial shades in place, the learning curve is more easily navigated. “We’re now starting to understand the mechanisms of why we’re getting a certain color,” Marsh adds. “It’s not just by chance anymore.”

P&G expects to launch an additional five to 10 hues in the next 12 months. The

company has been successful at the blond end of the spectrum but has had some dif-ficulty with color uptake on red shades, which are historically problematic because the small color molecules tend to fade rap-idly and are easily broken down in the sun.

P&G is now working on the next genera-tion of the technology while also starting to apply it to its other hair color brands and determining how to bring it into the salon business, Marsh notes. “We see the technol-ogy as a completely new platform for hair color,” she says. “It will be big, and it will show the industry how we do hair color.”

As for me, if genetics is any predictor, P&G has about 10 to 15 years to master a brunette shade with auburn highlights. I’m more than happy to provide samples, if needed. ■

Solvay Chemicals, Inc.713.525.6500 FAX: 713.525.78061.800.SOLVAY C (800.765.8292)www.solvaychemicals.us

Copyright 2008, Solvay Chemicals, Inc.

All Rights Reserved.

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oda Ash IPH, an important

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Solvay Chemicals. A fresh look.

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COLOR CONDITIONS

Innovative chemistry leads to healthier dyed hair

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Bleach

engine

Solution

basicity

Bleach melanin

& lighten hair

Hair fi ber

condition

NH3 + H

2O

2pH 10–11 Reactive species:

HOO–, HO•

(NH4

)2CO

3 + H

2O

2

+ C2H

5NO

2• Na

Sodium glycinate

pH 9 Reactive species:

HCO4–, CO

3•–

20–30 minutes

10 minutes

Color formation time

SOURCE: Procter & Gamble