Green chemistry takes root

08/06/2007
By From USA Today

By Elizabeth Weise

  A new kind of chemical revolution is brewing, 150 years after the first one transformed modern life with a host of conveniences.

This 21st-century revolution ߞ; called green chemistry ߞ; is a reaction to the environmental and economic costs that often are the dark underbelly of such a transformation.

The fundamental idea of green chemistry is that the designer of a chemical is responsible for considering what will happen to the world after the agent is put in place, says John Warner of the University of Massachusetts-Lowell, which hosts the nation's only doctoral program in green chemistry.

In the past 'we've created a mess and then come up with bandages to make it less bad,' says Paul Anastas, who was formerly with the White House Office of Science & Technology Policy and now heads the Green Chemistry Institute of the American Chemical Society.

But by rethinking chemical design from the ground up, green chemists at universities and in private industry are developing new ways to manufacture products that fuel our economy and lifestyles, without the damages that have become all too evident in recent years.

In fact, green chemistry has gone from blackboard conjecture to a multimillion-dollar business in the past 15 years. 'Chemical manufacturers are understanding that part of their costs ߞ; and therefore subtractions from their bottom line ߞ; are waste and environmental disposal,' says Mary Ellen Weber of the Environmental Protection Agency.

The stakes are high indeed. Cleaning up chemical messes is growing ever more costly. This fall, the DuPont company agreed to pay up to $600 million in fines and settlement costs over environmental damage caused by production of Teflon and Gore-Tex. General Electric will spend years and tens of millions of dollars to clean up PCBs it discharged into the Hudson River. Other companies face costs in the hundreds of millions of dollars to clean up dioxins, perchlorate, mercury and asbestos.

 

  What companies are doing

But keeping the planet safe doesn't have to mean giving up non-stick pans and Gore-Tex. Typically the non-stick coating Teflon is manufactured in water, requiring a particularly nasty chemical called PFOA. But by re-thinking the fundamental way that the molecules making up Teflon are put together, Joseph DeSimone and his colleagues at the University of North Carolina-Chapel Hill instead found a way to do it in carbon dioxide, the stuff you'd find in tanks at McDonald's to put the fizz in soda.

Carbon dioxide, it turns out, works so much better as a manufacturing medium for Teflon that no PFOA is required. DuPont has invested $275 million in a plant in North Carolina that makes one form of Teflon using this PFOA-free method, possibly saving a fortune in long-term cleanup costs.

Historically, Americans have thought of economics and the environment as a trade-off ߞ; you can do well by one or the other, but not both. Green chemistry changes that equation, says Anastas.

That's especially important as companies are being called on to do 'full cost accounting,' says Scott Noesen, director of Sustainable Development at Dow Chemical. That's the term used for dealing with the fact that the days are over when companies didn't have to worry about things such as chemical disposal, emissions and cleanup.

An example is something as mundane as electroplating a sports trophy. The trophy is made of inexpensive metal, which is sent to an electroplating facility for a thin coating of silver, chrome or brass. For transport, the trophy is coated with oil to keep it from corroding ߞ; oil that has to be stripped before the trophy can be electroplated.

Traditionally that cleaning was done in a hot bath of a fairly toxic solvent, 'in many cases a solvent that was recognized as a carcinogen,' says Kenneth Geiser, director of the Toxics Use Reduction Institute at the University of Massachusetts-Lowell.

But green chemists have found ways to add detergent-like chemicals to plain hot water that clean just as well as other solvents and are thousands of times less toxic, as well as being cheaper to buy, cheaper to use and cheaper to clean up.

'If you're a company using toxic materials, then you've got toxic waste, and it's very expensive to deal with it. So there's a tremendous incentive to reduce the hazard component,' says Terry Collins, who directs a green chemistry institute at Carnegie Mellon University in Pittsburgh.

Which is why supporters say that when you think green chemistry, don't think granola, unbleached toilet paper and draconian regulations. 'There's not a regulatory bone in its body, because it's about innovation and increasing profits while doing what's best for the environment and human health,' says Anastas.

Following nature's lead

One ploy of green chemistry is to work more like Mother Nature. Plants, for example, have access only to air, a few trace minerals in the soil and energy from the sun, yet they carry out hugely complex chemical transformations.

Traditionally, chemistry has gone for an A + B = C approach. Find two things to combine to get just the substance you want, and you're done. 'Historically, some people have called the chemical industry 'heat, beat and treat,' ' says Dow's Noesen.

Nature uses slower but less energy- and input-intensive methods. For example, complex biomolecular machinery can take A, add B to get D, then take E, add some F, bits of G, H and I to get K, then combine D, K and a few dozen other examples of complex molecular gymnastics to finally come up with the desired C.

One example is a Cargill Dow product that uses corn to make a plastic-like film. Rather than using ever-scarcer petroleum, NatureWorks uses bacteria to ferment sugars from the corn to produce lactic acid. That is then purified and turned into the film.

The process uses 20% to 50% fewer fossil-fuel resources than comparable plastics and is biodegradable. The film can be made into candy and food wrappers, and the company also is looking at it as a carpet backing. Cargill already has one plant up and running in Nebraska. And company officials are looking at using other grains such as wheat and rice.

Some environmentalists, though, say green chemistry is simply a public relations stunt by manufacturers. 'It's hard for us to take this too seriously, because they're hiding 99% of their pollution behind this one clean activity,' says Rick Hind, legislative director of the Greenpeace Toxics Campaign.

Hind says safer, effective and available proven technologies already exist; the companies just don't want to use them because they wouldn't make as much money. 'It's kind of like they have the cure to cancer and they're not using it; it's just a little cottage industry,' he says. 'These solutions aren't just on the shelf, they're on the market someplace.'

But Lauren Heine of the environmental group GreenBlue.org disagrees. While environmental groups love to have campaigns and push to get rid of dangerous chemicals, they also 'have figured out that they run into problems if they get someone to ban a substance and there's no alternative,' says Heine.

EPA started the movement

While some chemists had been working along these lines for years, green chemistry got its big start at the Environmental Protection Agency.

When the Pollution Prevention Act of 1990 established a national policy to prevent or reduce pollution 'at its source whenever feasible,' the agency began creating programs to encourage that. Through research grants, public-private partnerships and its coveted Presidential Green Chemistry Challenge awards, the EPA has helped green chemistry go from the fringe to the mainstream in chemistry.

So if green chemistry is such a blindingly obvious idea, 'why in 2004 are people acting like it's a revolutionary concept?' asks Warner of the University of Massachusetts.

The answer is simply that toxicity and environmental impact have never been taught as part of the innate set of qualities ߞ; such as boiling point ߞ; that all chemicals have. 'If I stood in front of a chemistry class and held a glass of water up and asked, 'What are the characteristics of this material?' no one is going to answer, 'It's not toxic,' ' Warner says.

That's slowly changing. Toxicology courses are starting to show up in chemistry departments. Textbooks are beginning to incorporate information about environmental outcomes. More doctoral programs in green chemistry are being considered.

The change, as it percolates through the field, will be tremendous, Warner believes. Today, most students who want to change the world end up being activists. 'How many 18-year-olds who care about the planet say, 'I'm going to go be a chemist'?

'But now they can go to the lab and invent something that can save the world.'

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