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ers properly—for a total proposed fine of $2,517,000. "We have cited similar violations . . . at this plant, yet tragedies continue to occur," Charles N. Jeffress, OSHA administrator, says. "What is really needed here is a full reassessment of worker mercially significant. But he safety and health in all areas of the plant, says Tarascon's observations significantly improved training for em"are very important because ployees, and afirmcommitmentfromthe they clearly demonstrate that plant and corporate management to nanomaterials have different make safety an ongoing high priority." chemical and electrochemical Labor Secretary Alexis M. Herman properties and reactivities that also had strong words about Phillips. can be exploited for batteries "Unfortunately, this tragedy was not an and other applications." isolated incident, but one in a series of inOnce the French research- cidents at this site," she stated. "Three crystal structure of the anode. Another ers had validated the electrochemical workers lost their lives in explosions at class of lithium-ion batteries releases lith- performance of the transition-metal oxide this plant in less than a year's time, and 23 ium ions from the cathode to form an in- electrodes in test cells with lithium metal, others were killed in a major explosion in termetallic phase such as a lithium-tin al- they built a lithium-ion battery, in which 1989." Two people died in June 1999 in loy at the anode. In either case, the pro- IiMn 2 0 4 serves as the cathode and CoO another explosion at the K-Resin unit cess is reversed when the batteries are as the anode. These new batteries retain Phillips disagrees with OSHA's con100% capacity for about 100 discharge-re- clusions, pointing out that it had traindischarged during use. For 20 years, scientists have thought charge cycles. Tarascon acknowledges ing and certification programs in place that one or the other of these two mecha- that more work needs to be done because years before the March explosion. "We nisms was a necessary basis for a good portable electronic devices require bat- will contest the citations vigorously, and lithium-ion battery electrode material, teries that can handle a minimum of 500 we believe there will be a favorable outTarascon says. But he and his col- cycles. Nevertheless, he says, these re- come for the company once the facts are leagues—including Ph.D. candidate Phi- sults "open up a completely new way to presented in the appropriate forum," lippe Poizot, who carried out much of the look at electrode materials for lithium-ion Phillips says in a statement. work—believe they have found a third batteries." Following the incident and discuspath. They attribute this to the fact that Sophie Wilkinson sions with labor unions and OSHA, Chevtheir anode's crystal structure has no ron Phillips officials say the company has empty sites for lithium ions to move into, decided to establish special safety educanor can it form alloys with lithium. tion programs for Houston Chemical Complex workers, hire an independent The team began by building test cells consultant to audit safety at the K-Resin that paired lithium-metal electrodes with a plant and elsewhere in the complex, and variety of transition-metal oxide electrodes expand the safety staff there. in which the metal was either cobalt, nickel, copper, or iron. During discharge of The company also created four safethese lithium batteries, CoO was reduced Phillips Petroleum will fight more than ty teams that are examining the human by lithium to form particles of Co dis- $2.5 million in citations handed down by and mechanical factors that create safepersed in a lithia (li 2 0) matrix. That reac- the Occupational Safety & Health Adtion is predictable, according to the re- ministration following the agency's rest searchers. But the fact that the reaction view of the fatal March 27 explosion at c -i can be reversed during recharging is sur- the K-Resin plant in Phillips' Houston E prising because "li 2 0 has always been re- Chemical Complex in Pasadena, Texas. ported to be electrochemically inactive." OSHA determined that a "runaway" The researchers speculate that they reaction in an out-of-service butadiene were successful in reversing the reaction tank caused the explosion that killed because their CoO breaks down during one and injured 69. Furthermore, OSHA thefirstdischarge step into nanoscale Co says the tank did not have pressure or particles, which possess enhanced reac- temperature gauges that could have tivity. There is precedent for dramatic warned workers of danger, that workers change in behavior based on particle size. were not properly trained to handle By way of analogy, the researchers point butadiene, and that a valve was not propto the drastic drop in melting point from erly locked out, allowing butadiene to 1,064 °C to 200 °C when gold particles continue flowing into the tank. K-Resin is a styrene-butadiene copolymer. are reduced to a size below 20 A. Daniel H. Doughty, manager of SanIn all, OSHA investigators allege 50 vidia National Laboratories, lithium-battery olations of safety standards at the HousR&D department, is uncertain whether ton Chemical Complex—30 of which are March 27 explosion led OSHA to Impose the new battery materials will be com- willful violations for failure to train work- $2.5 million fine. French team Includes (from left) associate professors Lolc Dupont and Stephana Laruelle, with Poizot, Tarascon, and engineer Sylvle Grugeon.
OSHA Fines Phillips $2.5 Million For Fatal Explosion
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ty problems at the K-Resin plant before it is brought on-line again. According to OSHA, Chevron Phillips Chemical—the joint venture between Phillips Petroleum and Chevron Corp. that now owns the plant—has 15 working days from receipt of the citations and penalties to contest them with the independent Occupational Safety & Health Review Commission. Alex Tullo
Aventis Suspends Bt Cora Seed Sales Aventis CropScience, Research Triangle Park, N.C., has suspended sales of its genetically engineered StarLink brand corn seed. This is the first time a transgenic seed has voluntarily been withdrawn from the market in response to safety concerns. And Kraft Foods and the Grocery Manufacturers of America (GMA) are seeking stricter federal regulation of biotechnology crop products. StarLink corn has been approved for use in animal feed but not yet for human consumption. It was detected in Taco Bell taco shells in mid-September (C&EN, Sept 25, page 13). A coalition of environmental, consumer, and health groups had commissioned Genetic DD, an independent testing firm in Fairfield, Iowa, to test the taco shells. Genetic ID found that 1% of the corn in the samples is StarLink. A few days later, Kraft Foods, the distributor of the taco shells, reported similar results from separate tests of the shells and promptly recalled the product from grocery store shelves. StarLink, which is engineered with a gene from Bacillus thuringiensis (Bt) to produce an insecticidal protein, has not yet been approved for human consumption because of concerns that the protein might provoke allergic reactions. That protein, called Cry9C, is heat stable and resists digestion, two characteristics associated with food allergens. In StarLink corn kernels, the insecticidal protein is expressed at levels that are 10- to 100-fold higher than levels of insecticidal proteins in other varieties of Bt corn. Kraft and GMA are now calling for fundamental regulatory changes. First, they do not want genetically modified crops approved for livestock use to enter the market until they have also been approved for use in food. Second, they want a fully validated procedure to be in place
to test for transgenes in crops and in processed foods before a new crop is approved. The Food & Drug Administration has not yet developed procedures for such tests. Finally, Kraft and GMA want mandatory review of all new biotech crops by the appropriate agencies before seeds are marketed. Currently, reviews are voluntary, but FDA is developing guidelines for mandatory reviews. "We think Aventis* decision was a prudent step in view of the fact that Cry9C may be getting into food," says an Environmental Protection Agency official. EPA is now planning to take a much harder look at partial registrations. The taco shell recall and suspension of
seed sales have prompted renewed criticisms of FDAs oversight of transgenic food. Rep. Dennis J. Kucinich (D-Ohio) and 15 other members of Congress have written to FDA, asking it to determine whether other corn food products are contaminated with StarLink corn. Kucinich introduced a bill (H.R 3377) in November 1999 that requires labeling of all foods containing any level of genetically engineered product Although StarLink corn accounts for only a tinyfractionof the U.S. transgenic corn acreage, the suspension of and publicity about this variety may further depress the total biotech corn seed market (see page 21). Bette Hileman
Single Molecules React Via Microscope Tip Carrying individualism to new heights, scientists report that they've performed a complete chemical reaction with single molecules—using the tip of a scanning tunneling microscope. This demonstration of nearly irreducible fine control has some chemists envisioning new, exotic molecules created by selectively cutting and pasting atoms and molecules together. Physicist Saw-Wai Hla, physics professor Karl-Heinz Rieder, and their colleagues at the Free University in Berlin developed a molecular-scale version of the well-known Ullmann reaction, a process in which iodobenzene breaks apart with the help of a copper powder catalyst, allowing liberated phenyl molecules to fuse into biphenyl [Phys. Rev. Lett., 8 5 , 2777 (2000)].
Long a staple tool of the physicist, the scanning tunneling microscope (STM) creates pictures of atomic hills and valleys on a surface by measuring the variation in tunneling current between the tip and the surface. But researchers increasingly are using STM tips not only to image atoms and molecules, but to manipulate them as well. For example, physics professor Wilson Ho, now at the University of California, Irvine, and colleagues dropped carbon monoxide molecules from the tip of an STM on top of an iron atom to form Fe(CO)2 (C&EN, Nov. 29,1999, page 9). Now, Hla and Rieder show they can also use the STM tip to break and create chemical bonds. In their STM version of the Ullmann reaction, a few iodobenzene molecules squat on a copper substrate at 20 K, a temperature sofrigidthat the reaction won't take place without an energetic push. That push comes in the form of electrons injected from the STM tip into a single iodobenzene molecule. The iodinephenyl bond promptly breaks, evidenced by striking images showing two lumps where there once was one. The researchers STM images show two iodobenzene molecules on a Cu repeat the process substmte (top left). Next, a voltage pulse from the STM tip with another iodobenbreaks the iodine-phenyl bonds (top right and middle left). zene molecule. The iodine atom is moved out of the way (middle right), and finally, the two phenyls are brought together (bottom). Next, the authors drag the now unmatOCTOBER 2,2000 C&EN
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