Third Annual Awards For Presidential Green Chemistry Challenge Recognize Innovations

WASHINGTON, June 24 -- This year's winners of the Presidential Green Chemistry Challenge Awards were announced here today. Now in its third year, the awards program is part of President Clinton's Reinventing Environmental Regulations Initiative to promote industrial ecology. "Green chemistry" is chemistry designed to reduce or eliminate the use of generation of hazardous substances.

The award recipients and their achievements are:

• Karen M. Draths and John W. Frost (Michigan State University, East Lansing): genetically engineered microbes that can manufacture starting materials for nylon and other products from nontoxic, readily available glucose.
• Barry M. Trost (Stanford University, Stanford, Calif.): the concept of "atom economy," demonstrated by efficient catalytic reactions with which to make pharmaceuticals and specialty chemicals, thereby reducing waste streams and conserving nonrenewable resources.
• Pyrocool Technologies, Inc. (Lynchburg, Va.): a more efficient yet less environmentally damaging agent to extinguish and cool a wide variety of fires.
• Flexsys America L.P. (Akron, Ohio): a new route to make an ingredient of rubber that significantly reduces waste streams and eliminates the need for toxic chlorine, benzene, and xylene.
• Argonne National Laboratory (Argonne, Ill.): low-cost synthesis of a nontoxic, biodegradable solvent that can economically replace many toxic, petroleum-derived solvents in the manufacture of electronics, paints, textiles, cleaners, and other products.
• Rohm and Haas Co. (Philadelphia, Penn.): a new family of insecticides that are highly selective for destructive caterpillars and beetle grubs, and thus pose little risk to other organisms from honeybees to humans.

The U.S. Environmental Protection Agency administers the awards. The EPA, in partnership wit the National Science Foundation, also funds about $7 million annually for research grants dedicated to green chemistry. (For more details about the program and awards, see accompanying factsheet.)

The six presidential awards fill five categories, with a tie in academia this year:

For Design of Safer Chemicals

• Chemists at Rohm and Haas Co. have discovered a new and highly selective method to control crop-eating caterpillars and turf-destroying grubs. Most insecticides currently available attack various parts of the nervous system, parts of which are sufficiently similar among organisms to suffer harm in untargeted insects and reptiles to birds and mammals, including humans. The Rohm and Haas insecticides, on the other hand, mimic a chemical signal that tells the developing pests to molt. The company says caterpillars and beetle grubs stop eating shortly after exposure and soon die. The signal, called 20-hydroxy ecdysone, neither occurs nor has any function even in spiders, honeybees, flies, or earthworms. The insecticides' new mode of action also counters resistance to older pesticides. For example, Confirm insecticide controlled an outbreak of organophosphate-resistant leafrollers on apples in 1996. It has been classified as a reduced-risk pesticide by the EPA; a related product called Intrepid is expected to follow. Rohm and Haas is registering the new family for use on cotton, walnuts, pecans, apples, vegetables, and other crops.

Among Academia

• The husband-and-wife research team of John W. Frost and Karen M. Draths has designed new strains of genetically engineered bacteria that eliminate not only harmful industrial processes, but also the need for petroleum-based starting materials. Currently, nearly all of the most common building blocks that end up as pharmaceuticals, plastics, food additives, and other products come from petroleum, of which the United States must import more than half its total needs. In addition, many of the materials and byproducts, such as benzene and nitrous oxide, are toxic or damage the environment. In contrast, the Michigan State chemists' bacteria start with the simple sugar glucose, derived from a robust and renewable resource: plants. The biocatalysts, which include innocuous strains of Escherichia coli, can manufacture adipic acid (used to make nylon), catechol (food flavors, pharmaceuticals, insecticides), and an antioxidant called DHS. Preliminary estimates suggest little extra cost and perhaps even savings.

• Barry M. Trost's concept of atom economy has redefined the way chemists measure synthetic efficiency. His deceptively simple catalytic reactions illustrate his concept by addressing inefficiency in pharmaceutical and specialty-chemical manufacturing. The Stanford chemist points out these industries have often emphasized high selectivity at the expense of atom economy: one ton of product requires five-50 tons of raw materials for specialty chemicals and 25-100 tons for pharmaceuticals. Such reactions generate significant amounts of byproducts for expensive treatment and disposal, as well as squander resources--often nonrenewable ones like petroleum.

  In answer, Trost demonstrates atom economy (aiming to get as much out of a reaction flask as one puts in) is not incompatible with high selectivity. For example, he can neatly construct a building block of a promising new HIV protease inhibitor from inexpensive, readily available molecules like oxygen and butadiene. Traditional methods begin with complex amino acids, which one must first break down, discard extraneous parts, and then reassemble step-by-step into the building block. Trost has also designed efficient new reactions to produce an anti-ulcer agent, vitamin D, fungicides, and the fragrance from the oil of rose.

Among Small Businesses

• In 1993, Pyrocool Technologies, Inc. developed a new fire-fighting agent that cools as well as extinguishes a variety of burning materials, yet is rapidly and completely broken down by bacteria in the environment. It contains no ozone-depleting halons, nor fluorsurfactants or glycol ethers, both of which can contaminate groundwater resources for years. Currently, firefighters release millions of tons of such chemical extinguishers into the environment every year. Only four gallons of Pyrocool FEF (for Fire Extinguishing Foam) treats 1000 gallons of fresh or sea water, however, in contrast to 30 to 60 gallons per 1000 for conventional foams. The agent also helps water cling to newly extinguished material, reducing the risk of spontaneous re-ignition. Pyrocool FEF has extinguished fires both in the United States and abroad. In 1994, it took 12.5 minutes to quench a crude-oil fire aboard a tanker that Lloyd's of London estimated would take 10 days. Company president Robert E. Tinsley, Jr. says the rapid extinguishment prevented 80 percent of Nassia's 98,000 tons from polluting one of the world's busiest commercial waterways, the Bosporus Strait which splits Turkey.

For Alternative Synthetic Pathways

• Durable rubber requires ingredients that protect it from degradation by environmental factors like ozone, and Flexsys America L.P. has highly improved the means to make such an antiozonant. The new route reduces organic waste by 74 percent, inorganic waste by 99 percent, and waste water by 97 percent. It also eliminates the need for toxic chlorine, benzene, and xylene, which improves safety as well as protects the environment. Traditionally, Flexsys (a joint venture of Solutia, formerly part of Monsanto, and Akzo Nobel) has made 4-aminodyphenylamine (4-ADPA) by chlorinating benzene, then processing the product further in the solvent xylene. Chlorine came back out in a stream of inorganic salts and organic byproducts that is difficult and expensive to treat. The new process uses only hydrogen and catalyst to link the two pieces of 4-ADPA together directly--a breakthrough in the field, the company says. Its yield is 96 percent. Flexsys, the world's largest producer of 4-ADPA, demonstrated the process at a pilot plant in 1993.

For Alternative Solvents or Conditions

• Ethyl lactate, a versatile solvent long known to be nontoxic and biodegradable, until now has cost about double the price of many undesirable but economical solvents. A new process developed at Argonne National Laboratory, however, brings the cost down to compete directly with about 80 percent of current solvents, many of them toxic, environmentally damaging, petroleum-derived, or all three. It also eliminates the large amounts of salt waste (sometimes 1:1 with products) that conventional processes generate. Argonne's synthesis begins with carbohydrates from plants and uses selective membranes to minimize byproducts and their side reactions. At $0.85-1.00 per pound, ethyl lactate could replace as much as five billion pounds of solvents now used worldwide to manufacture semiconductor chips, industrial and household cleaners, adhesives, paints and coatings, and to remove ink from recycled paper. The synthesis can also make very pure but low-cost lactate ester, an ingredient of biodegradable plastics and other products. Argonne's industrial partner (NTEC Inc.) plans to open a demonstration plant in 1999, followed by full-scale production of 100 million pounds per year.