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The textile dyeing industry is among the worst polluters and water wasters. Dye houses in countries such as India and China dump hazardous chemicals into waterways, making them unsafe for drinking, and haven’t been eager to overhaul centuries-old practices. Tony Leonard, 64, a textile chemist from North Carolina, and Michael Harari, the 29-year-old son of a New York City apparel maker, are out to change that.
In 2010, the two founded a startup to commercialize Leonard’s improvements to the dyeing process. The status quo “requires an excessive amount of water and chemicals,” Leonard says. ColorZen, their 20-person venture, unveiled a nontoxic treatment for cotton fiber on July 24 that they say will speed dyeing while eliminating the vast majority of chemical, water, and energy use.
Coloring a ton of fabric can require 100 to 300 tons of water, most used to rinse off powerful fixing agents, says Susan Egan Keane, a senior analyst for the Natural Resources Defense Council. ColorZen’s treatment changes the cotton’s molecular composition, making it more receptive to dye without creating toxic discharge.
In June, ColorZen tested its formula on about 400 pounds of cotton fiber, successfully dyeing it with 95 percent fewer chemicals, 90 percent less water, 75 percent less energy, and 50 percent less dye in less than one-third of the standard eight hours. The Hohenstein Textile Testing Institute certified in July that ColorZen-treated cotton is free of harmful substances. And ColorZen treatments don’t require dye houses to hire more personnel or retrofit their machines, Harari says: “They don’t have to change their facility one iota.”
Leonard spent more than a decade developing this treatment, but he has been tinkering with dyeing formulas since 1970, when he graduated from North Carolina State University with degrees in textile chemistry and textile technology. He met Harari while consulting for the younger man’s father, and a shared sense of purpose led them to team up. “If we can use our technology to improve the waterways … everywhere, that’s the goal,” says Leonard.
Persuading the industry to change remains difficult. “The way dye masters look at it, the whole dyeing process is a lot of alchemy,” Egan Keane says. To get paid, “they have to match the color ordered by the customer exactly.” ColorZen, which treats the cotton at its factory in southern China, has assembled a team of five specialists to meet those kinds of demands and is also pitching the potential image boost to apparel makers and retailers.
ColorZen’s founders say development cost “millions,” but they expect to turn a profit next year—and hope environmentalists will aid in that effort. Alexandra Cousteau, the granddaughter of renowned oceanographer Jacques-Yves Cousteau, is already a convert. “This kind of technology is incredibly needed to help make our textile industry more sustainable,” she says.
Cotton treatment that makes dyeing more efficient and less toxic
Prodding dye houses to change centuries-old processes
Environmentalists worried about the water supply