Published: March 01, 2006

U.S. Regulators, Experts Launch "Green" Nanotechnology Effort

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By Cheryl Pellerin, Washington File

Small science will develop products in environmentally safe ways

U.S. regulators and experts who specialize in nanotechnology (science on the scale of single atoms and molecules) have launched an effort they say will help minimize environmental and health risks that could be associated with such processes and products.

The initiative - a series of meetings on "green" nanotechnology - is led by Barbara Karn, manager of the U.S. Environmental Protection Agency's (EPA) nanotechnology research program.

"Key nanotechnology companies and researchers," Karn said during the first GreenNano meeting February 16, "are taking responsibility to ensure that nanotech products are produced in environmentally safe ways."

Nanotechnology involves imaging, measuring, manipulating and manufacturing things on a scale of 1-100 nanometers. A nanometer is 1 billionth of a meter; a sheet of paper is about 100,000 nanometers thick.

"The GreenNano series," Karn said, "is designed to explore everything from new nanotechnology products claiming to be better for the environment - because of saved energy, reduced waste, or safer materials used - to smart engineering and business practices."

The effort also will examine government policies that offer incentives for developing such low-risk practices, and highlight research in green nanotechnology applications, including an eight-session nanotechnology research and environment symposium at the American Chemical Society meeting March 26-30 in Atlanta.

"Nanotechnology holds tremendous potential for pollution prevention and sustainability, especially in the areas of clean water, energy and efficient sensors," said David Rejeski, director of the Project on Emerging Nanotechnologies at the Woodrow Wilson International Center for Scholars in Washington.

"We are interested in bringing together stakeholders from government, industry, the research community and citizen organizations," he added, "who are committed to ensuring that nanotechnology helps create a new, more sustainable economy."

Karn, who is on detail as a visiting scientist to the Project on Emerging Nanotechnologies, said that to create nanotechnology products using environmentally friendly processes will require an approach called green chemistry.

Green Chemistry

Green chemistry means designing chemical products and processes in a way that reduces or eliminates hazardous substances from the beginning to end of a chemical product's life cycle.

The practice began in the United States with the passage of the Pollution Prevention Act of 1990, which established a national policy to prevent or reduce pollution at its source whenever feasible.

Reducing pollution at the source, according to the act, "is fundamentally different and more desirable" than managing waste and controlling pollution.

Soon after the act became law, the EPA Office of Pollution Prevention and Toxics (OPPT) began to explore the idea of developing or improving chemical products and processes to make them less hazardous.

In 1991, OPPT launched a model program to provide financial support for research projects that included pollution prevention in the synthesis of chemicals.

Since then, the EPA Green Chemistry Program has built collaborations with academia, industry, other government agencies, nongovernmental organizations and international partners to promote pollution prevention through green chemistry.

In 1998, Paul Anastas, director of the Green Chemistry Institute of the American Chemical Society, and John Warner, professor of plastics engineering and community health and sustainability and director of the Center for Green Chemistry at the University of Massachusetts-Lowell, wrote the first textbook on the topic. Green Chemistry: Theory and Practice describes 12 principles that give chemists a road map for implementing green chemistry.

At the GreenNano meeting, Warner said green chemistry is unique in looking at the risk equation - risk equals hazard times exposure - and recognizing that there is a great deal of benefit in focusing not on exposure but on the intrinsic hazard of a material or a process.

Society usually deals with hazardous materials in terms of exposure, he added. "We wear gloves to protect our skin, we wear masks to protect our lungs, we wear goggles to protect our eyes, and we install scrubbers and filters and smokestacks to protect the air, the land and the sea."

All such exposure-prevention technologies cost money, Warner said.

Not using hazardous substances in the first place would reduce industry costs for storage, transportation, disposal, regulation, liability, worker health and safety and corporate and community relations.

The problem is, Warner said, that making materials in an environmentally benign way is still an emerging science, and green chemistry is seeking to address that gap.

A technology must meet three criteria to be considered green: it must be environmentally benign, and it must perform better than conventional alternatives, and it must be more economical than conventional alternatives.

One incentive for developing such technological advances is the EPA Presidential Green Chemistry Challenge awards.

The program gives individuals, groups and organizations a chance to compete for annual awards in recognition of innovations that incorporate the principles of green chemistry into chemical design, manufacture and use and that industry has used or can use to prevent pollution. A total of 150-200 technologies have received awards since the program began in 1996.

Using the principals of green chemistry in the emerging science of nanotechnology is an "unprecedented opportunity," Warner added, "to do nanotechnology right the first time."

Green Nanotechnology

"If we look at the state of the art for nanotechnology manufacturing," said James Hutchinson, professor of chemistry at the University of Oregon and director of the university's Materials Science Institute, "we have to accept the fact that in this early stage of development we use many hazardous reagents [any substance used in a chemical reaction], a large volume of toxic solvents, and we have very little yield."

Hutchinson, a presenter at the GreenNano meeting, holds a U.S. patent for a process his laboratory created to manufacture a gold atom nanoparticle without the environmentally harmful effects usually associated with its production.

When he first began working in nanotechnology research, Hutchinson said, he and his students used a chemical procedure for making certain nanomaterials that led to several fires in the laboratory.

"As research adviser," he said, "my job was to stand behind the students with a fire extinguisher. This is not the way forward for any kind of manufacturing."

The chemical reaction used two hazardous substances - diborine, which is highly toxic and bursts into flame near room temperature, and benzene, a cancer-causing chemical used as a solvent.

Looking for an alternative approach, Hutchinson and his students replaced diborine with an environmentally benign chemical called sodium borohydride, and used a different solvent system that eliminated the use of benzene.

The process, Hutchinson said, "is now safer, easier, you make more material than before ... it's faster ... and, significantly, it's cheaper."

The price difference, he added, was "$300,000 a gram for the material on the market produced the old-fashioned way, or about $500 a gram our way. That's a significant performance benefit."

Green chemistry can help nanotechnology develop as a responsible industry, as a tool that drives technology development, Hutchinson said.

"There are already examples of success that allow us to think about the reality of designing materials in a green way, manufacturing in an efficient way and optimally applying the nanomaterials."

Source: U.S. Department of State