[Pharmwaste] Green Chemistry: Scientists Devise New "Benign by Design" Drugs, Paints, Pesticides and More

[DeBiasi, Deborah (DEQ)]

http://www.scientificamerican.com/article.cfm?id=green-chemistry-benign-
by-design


Features -  May 28, 2010

Green Chemistry: Scientists Devise New "Benign by Design" Drugs, Paints,
Pesticides and More

Chemists are usually asked to invent a solution, but without considering
hazardous by-products. Green chemists now are doing both with success,
but will it take regulations to enforce the approach broadly?

By Emily Laber-Warren 

Back in the days when better living through chemistry was a promise, not
a bitter irony, nylon stockings replaced silk, refrigerators edged out
iceboxes, and Americans became increasingly dependent on man-made
materials. Today nearly everything we touch-clothing, furniture,
carpeting, cabinets, lightbulbs, paper, toothpaste, baby teethers,
iPhones, you name it-is synthetic. The harmful side effects of
industrialization-smoggy air, Superfund sites, mercury-tainted fish, and
on and on-have often seemed a necessary trade-off.

But in the early 1990s a small group of scientists began to think
differently. Why, they asked, do we rely on hazardous substances for so
many manufacturing processes? After all, chemical reactions happen
continuously in nature, thousands of them within our own bodies, without
any nasty by-products. Maybe, these scientists concluded, the problem
was that chemists are not trained to think about the impacts of their
inventions. Perhaps chemistry was toxic simply because no one had tried
to make it otherwise. They called this new philosophy "green chemistry."


Green chemists use all the tools and training of traditional chemistry,
but instead of ending up with toxins that must be treated and contained
after the fact, they aim to create industrial processes that avert
hazard problems altogether. The catch phrase is "benign by design". 

Progress without pollution may sound utterly unrealistic, but businesses
are putting green chemistry into practice. Buying, storing, and
disposing of hazardous chemicals is expensive, so using safer
alternatives makes sense. Big corporations-Monsanto, Dow, Merck, Pfizer,
DuPont-along with scrappy start-ups are already applying green chemistry
techniques. There have been hundreds of innovations, from safer latex
paints, household cleaning products and Saran Wrap to textiles made from
cornstarch, and pesticides that work selectively, by disrupting the life
cycles of troublesome insects. Investigators have also developed cleaner
ways of decaffeinating coffee, dry-cleaning clothes, making Styrofoam
egg cartons, and producing drugs like Advil, Zoloft and Lipitor. 

Over the past 15 years, green chemistry inventions have reduced
hazardous chemical use by more than 500 million kilograms. Which sounds
great, until you consider that every day the U.S. produces or imports
about 33.5 billion kilograms of chemicals. The annals of green chemistry
are full of crazy, fascinating stories, like a plan to turn the
unmarketable potatoes from Maine's annual harvest into biodegradable
plastics. Still, a decade after the phrase was coined, green chemistry
patents made up less than 1 percent of patents in chemical-heavy
industries.

What will it take for green chemistry to be more than the proverbial
drop in the bucket, a bucket full of toxic sludge? Some experts believe
that the answer is government intervention-not only laws that ban
harmful chemicals, but laws that simply require chemical manufacturers
to reveal safety data and let the market do the rest. "Right now,
companies that make chairs or cars or lipstick don't know which of the
chemicals they incorporate into their products are safe," says Michael
Wilson, an environmental health scientist at the University of
California, Berkeley. "Once that information becomes available, there
will be a demand for less toxic ingredients."

That question-to regulate or not to regulate-has split the community of
green chemistry advocates. Some oppose making green chemistry mandatory:
its principles are so sensible and cost-effective, they believe, that
industry will implement them voluntarily. Others, such as Wilson,
disagree. The key, he asserts, is "fundamental chemicals policy reform
in the U.S."

Now is a critical time: After decades of inaction, the U.S. government
is finally examining more aggressively the health effects of common
chemicals. The ambitious Safe Chemicals Act, unveiled last month in the
U.S. Senate, would require all industrial chemicals to be proved safe,
creating a strong incentive for the development of less harmful
alternatives. And the President's Cancer Panel released a landmark
report earlier this month decrying the "grievous harm" done by
cancer-causing chemicals such as bisphenol A in food and household
products.

The stakes are high, higher than most people realize. The companies that
make the 80,000 chemicals that circulate in our world are rarely
required to do safety testing, and government agencies are relatively
powerless. "This is pretty shocking, since most people assume that
someone is checking what's on the market. The ingredients in my shampoo?
The ingredients in my child's toys? No one's on the job? And that's the
answer: By and large, no one's on the job," says Daryl Ditz, a senior
policy adviser at the Center for International Environmental Law (CIEL)
in Washington, D.C.

"If we're going to continue on as an industrial society that's based on
synthetic chemicals, we've got to figure out a way around this stuff.
There's really no question about that," says Jody Roberts, an
environmental policy expert at the Chemical Heritage Foundation in
Philadelphia, Pa. "I think that's where the frustration for some people
is, that it needs to be happening faster."

Green chemistry's beginnings

Perhaps no one has gambled more on green chemistry than John Warner.
Along with Paul Anastas, the co-founder of green chemistry and now the
assistant administrator for the EPA's Office of Research and
Development, he helped create a federal awards program that brought the
field into the mainstream. And with Anastas he literally wrote the book:
Green Chemistry: Theory and Practice, what Warner calls "a how-to guide
at the molecular level." In it they establish 12 guiding principles for
chemists, concepts like preventing waste by incorporating as much of the
materials used into the final product, and choosing the least
complicated reaction. 

A dozen years ago Warner, 47, left a lucrative job at Polaroid to found
the nation's first doctoral program in green chemistry. In 2007, tired
of lecturing that green chemistry is the wave of the future, he decided
to prove it, founding a start-up, the Warner Babcock Institute for Green
Chemistry, in Wilmington, Mass. His firm, staffed by two dozen bright
young scientists, is an ingenuity factory. They are working on all kinds
of projects: a less energy-intensive way to make solar panels, a cheap
water purification device for the developing world, and materials that
mimic eye and liver tissue to substitute for live animals in toxicity
testing.

Some of the work is basic research. One of Warner's core technologies is
based on thymine, one of the four bases of DNA. When exposed to light,
thymine molecules attach to one another; because this reaction can be
harmful (think: skin cancer) many organisms possess enzymes tasked with
breaking those bonds. If you put thymine in a substance and expose it to
light, it hardens; apply enzymes and it softens again. No toxicity, many
potential applications. A scientist in Warner's lab is using this
technology to perm hair without caustic chemicals-simply by coating
curled strands with a thymine-based polymer then shining light to freeze
them in place. The technology could also act as a masking technique
during the manufacture of printed circuit boards. Or imagine truly
recyclable plastics that could be returned to their raw materials after
the user throws them away. 

That practical vision is a product of Warner's upbringing. He grew up in
Quincy, Mass., a tough working-class town south of Boston, and he hasn't
shed the local dialect. "I am a chemist. I make molecules," he says, as
if he could just as easily be building a house or an engine. In his
plaid shirt and scuffed sneakers, he comes across more like the kind of
guy you might bring your car to when it makes a funny rattle. Warner's
uncles, Sicilian immigrants, worked in construction and stone cutting,
and he sees no disconnect between his blue-collar beginnings and his
current gig running a 40,000-square-foot high-tech lab. "I had uncles
with half fingers. I respect that-doing things with your hands, creating
things," he says. "I feel that I'm working with my hands, but just in a
different kind of way."

To a chemist, atoms are like so many Lego blocks to arrange and
rearrange at will. Add a hydroxyl here, a phosphate there, and react
with various other chemicals to get the desired color, hardness,
transparency or other properties. "If we can draw a molecule, if it
doesn't violate some fundamental law, we probably can make it," Warner
says.

But chemistry was invented at a time when people weren't thinking about
the environmental impacts. Raw materials are typically derived from
fossil fuels. Turning them into the desired product can be a multistep
process involving hazardous reagents (chemicals that react with the
target material) and solvents (liquids or gases that provide an
environment for the reaction to take place). Reactions often generate
more unwanted than wanted chemicals. In making pharmaceuticals, for
example, it is not uncommon to end up with 25 to 100 pounds of waste for
every pound of medication.

Green chemistry starts with renewable resources such as plants or
microorganisms, recycles its reagents, uses less hazardous solvents, and
streamlines complicated processes. For example, in 2006 Pfizer changed
the way it makes its nerve-pain drug Lyrica, substituting two
plant-based enzymes for a common metallic catalyst called Raney nickel.
The process now occurs at room temperature and in water, takes four
instead of 10 steps, and has slashed waste and energy use by more than
80 percent. 

Why so slow?
Green chemistry is elegant. It's sensible. It has the potential to
improve public health and enhance the economy. But if everyone loves
green chemistry-scientists, environmentalists, politicians, corporate
leaders-then why hasn't it been more successful? After 15 years of
innovation, the chemical industry is as toxic as ever. The politicians
who lavish funding on nanotech dole out pathetically little to green
chemistry. The universities that train chemists still do not require
students to take a single course in toxicology. And green chemistry is
far from becoming a household phrase.

To many observers, the answer is clear: What's needed is more
regulation. "One way to think about it is to ask yourself: 'What is the
purpose of government? Why isn't everything done by voluntary exchange
among willing buyers and sellers?' The answer is, of course, that a lot
of important things that need doing won't be done voluntarily," says
Edward Woodhouse, a political scientist at Rensselaer Polytechnic
Institute in Troy, N.Y. "It does require stick as well as carrot."
Wilson and his Berkeley colleagues have acted on that principle; they
helped craft the nation's first green-chemistry laws, enacted in 2008 in
California. These laws require the state to identify, prioritize and
take action on chemicals of concern, to encourage safer alternatives,
and to make hazard information available to the state's businesses and
to the public.

Warner is all for transparency, but being a chemist himself, he knows
how his colleagues think, and he's concerned that if green chemistry
becomes mandatory, industrial chemists will misunderstand it, writing it
off as a policy-wonk proposal when in fact it is solid science, built on
the core principles of traditional chemistry. Warner favors the "build a
better mousetrap" philosophy: Do green chemistry by making alternatives
that are not only safer but effective and economical, and chemical
companies will eagerly adopt them.

But others insist that until heavyweights like Dow and ExxonMobil are
forced to own up to the dangers of their chemicals, smaller companies
developing clean alternatives won't be able to compete. "Some academics
say, 'If we had enough students and research dollars, then wonderful new
substances would flow from our labs and the world would beat a path to
our door,'" CIEL's Ditz says. "But if no one can distinguish between a
green molecule and a toxic molecule, it is almost impossible for safer
products to break into the market."

No shift this big happens without conflict, and outrage, Woodhouse says.
Average people need to know and care enough about chemical hazards to
pressure business and political leaders for change. "Most people have no
idea that many of the things in their houses are a danger to them," he
says. "I don't think that the urgent need for a benign chemical
transformation has been put out very effectively."

In addition, even when scientists come up with nontoxic, cost-saving
technologies, they don't always see the light of day. The up-front
expense of redesigning factories often eclipses the potential long-term
savings. "Your plants are set up to run nonstop. Any downtime, even if
it's going to save you a million dollars later, is costing you money
now," Chemical Heritage's Roberts says.

Warner's concern is that when government gets ahead of science, the
effort often backfires. "The ban will say, 'Use the best available
technology.' If the best available technology is nasty, the ban becomes
a license to use that technology," he says. "You can't legislate an
invention, only encourage it."

The other side of the coin, however, is that sometimes when government
gets ahead of science, science rushes to catch up. That happened in the
mid-1990s, when the chemical company Rohm and Haas learned that a ban on
tin-based marine paints was in the works. Tin-based paints had been used
on ships' hulls for years because they discouraged the growth of
barnacles, algae, bacteria and other unwanted hitchhikers. But tin is
toxic and it was accumulating in fish, seabirds and other animals. Japan
banned tin-based paints in 1992 and other nations were poised to follow
suit. Rohm and Haas had never made ingredients for marine paint-and
without the pending ban it would not have tried, because tin-based paint
manufacturers dominated the market. But Rohm and Haas already had a
mildew-fighting chemical t hat acted as a wood preservative . By
adapting that active ingredient, company scientists developed Sea-Nine,
a chemical that kills marine organisms by reacting with their own
chemistry, breaking down into nonhazardous components in the process.

However it happens, changing worldviews takes time. It took two decades
or more for global warming to gain any serious traction. Now it is seen
as an opportunity to develop a whole new sector of the economy:
alternative energy. The same could happen for green chemistry, as a
demand for cleaner products drives innovation.

What everyone agrees on is that, ultimately, green chemistry principles
must become so integrated into mainstream chemistry that the term loses
its meaning. Ironically, we'll know that green chemistry has succeeded
when it disappears. "The day that everyone from kindergarten students on
up gets it, we don't need the field of green chemistry anymore," Warner
says. "That is my goal, for it to be just the way everybody sees
science."

*     *     *

A GREEN CHEMISTRY PRIMER

To explain the goals of green chemistry, John Warner uses the metaphor
of the toolbox. Rather than wrenches, nuts and bolts, the drawers in the
chemical industry's "toolbox" contain commonly used processes, such as
ways to make carbon compounds or oxidation-reduction reactions. Most of
these processes involve hazardous chemicals. Green chemists aim to
create a new toolbox filled with less harmful alternatives, so that in
the future when chemists set out to design a molecule, they'll be able
to put their hands on benign tools to get the job done.

Here are some promising new technologies destined for the
green-chemistry toolbox.

TAMLs: There's no pretty way to say it-TAML is short for tetra-amido
macrocyclic ligand-but these apparently harmless chemicals break down a
variety of stubborn pollutants, including pesticides, dyes and
industrial runoff. Developed by Terrence Collins, a chemist at Carnegie
Mellon University in Pittsburgh, TAMLs mimic the enzymes in our bodies
that have evolved to fight off toxic assaults. Collins and his team
worked for two decades to develop these smaller, easy-to-build versions
of biological enzymes. When combined with hydrogen peroxide, TAMLs
neutralize many contaminants by breaking their chemical bonds.

Noncovalent derivatization: A longtime passion of Warner's (his license
plate reads "NCD"), noncovalent derivatization is chemistry with a light
touch. Covalent bonds are the strong connections between atoms that hold
molecules together. Normally, when chemists are dissatisfied with some
aspect of a molecule they are creating, they alter its structure by
breaking or adding covalent bonds. Such changes can involve multiple
steps and hazardous ingredients. Warner's breakthrough was to posit that
sometimes there's no need to create a new molecule. Simply combine the
existing molecule with another substance that interacts with it, and the
transient forces between them can effect the desired change. "With no
energy they find each other and form," he says. "Why does a bunch of
lipids fold up to form a cell membrane? Why does DNA form a double
helix? It's always these weak molecular structures."

Liquid CO2: Most of us know carbon dioxide as a gas (we exhale it) or a
solid (think: dry ice in fog machines). But when you put carbon dioxide
under pressure, it becomes a liquid. Liquid CO2 is a benign substitute
for the nasty solvents typically used to decaffeinate coffee. Just mix
it with green coffee beans, then take the pressure off. The carbon
dioxide evaporates, leaving behind a pile of white powder-caffeine. Do
the same thing to dirty clothes and you extract oils and grime without
using perchloroethylene, the notorious dry cleaning chemical.


Further Reading
*	Sacking Plastic: Are Restrictions on Plastic Bags an Effective
Way to Slow Landfill Growth and Save Petroleum?
<http://www.scientificamerican.com/article.cfm?id=earth-talk-sacking-pla
stic> 
*	A Himalayan Village Builds Artificial Glaciers to Survive Global
Warming [Slide Show]
<http://www.scientificamerican.com/article.cfm?id=artificial-glaciers-to
-survive-global-warming> 
*	Local Governments Lead Efforts to Combat Climate Change
<http://www.scientificamerican.com/article.cfm?id=local-governments-lead
-efforts-to-combat-climate-change> 
*	How Many Cancers Are Caused by the Environment?
<http://www.scientificamerican.com/article.cfm?id=how-many-cancers-are-c
aused-by-the-environment> 
 
*	New Mass-Screening Method Finds Additional Environmental Risks
for Diabetes
<http://www.scientificamerican.com/article.cfm?id=environmental-factors-
diabetes> 
*	Short-Chain Chlorinated Paraffins Draw EPA Scrutiny--After 70
Years
<http://www.scientificamerican.com/article.cfm?id=short-chain-chlorinate
d-paraffins-draw-epa-scrutiny> 
*	12 Events That Will Change Everything
<http://www.scientificamerican.com/article.cfm?id=12-events-that-will-ch
ange-everything> 
*	Sugar Within Human Bodies Could Power Future Artificial Organs
<http://www.scientificamerican.com/article.cfm?id=glucose-body-fuel-cell
> 








Deborah L. DeBiasi 
Email:   Deborah.DeBiasi at deq.virginia.gov (NEW!)
WEB site address:  www.deq.virginia.gov 
Virginia Department of Environmental Quality 
Office of Water Permit and Compliance Assistance Programs 
Industrial Pretreatment/Whole Effluent Toxicity (WET) Program 
PPCPs, EDCs, and Microconstituents
www.deq.virginia.gov/vpdes/microconstituents.html 
Mail:          P.O. Box 1105, Richmond, VA  23218 
Location:  629 E. Main Street, Richmond, VA  23219 
PH:         804-698-4028 
FAX:      804-698-4032 


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