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Home » August 23, 2010 Issue » Science & Technology » Texas Tech Lessons
August 23, 2010
Volume 88, Number 34
Texas Tech Lessons
Explosion highlights need to improve safety culture at university, initiates government oversight Jyllian N. Kemsley Texas Tech U REPERCUSSION The blast that injured Brown also damaged the lab.
1 of 6 8/28/10 5:16 PM Texas Tech Lessons | Science & Technology | Chemical & Engineering... http://pubs.acs.org/isubscribe/journals/cen/88/i34/html/8834sci1.html Texas Tech U EXPLOSIVE The purple compound made by the students was likely nickel hydrazine perchlorate.
On Jan. 7, 2010, Texas Tech University (TTU) graduate student Preston Brown was working with another graduate student to synthesize and characterize an energetic material, most likely nickel hydrazine perchlorate. Despite being told by their adviser, chemistry professor Louisa J. Hope-Weeks, to make no more than 100 mg of the material, the students synthesized 10 g.
They then divided up the product: Brown took half to prepare the sample to run characterization tests, and the other student took half for solubility studies. Because the product was lumpy, Brown placed his portion into a mortar. He believed that the compound was safe when “wet,” so he added some hexane and—wearing safety goggles but working at a bench in the middle of the lab, with no blast shield—“very gently, very, very gently” used a pestle to try to break up the chunks, Brown told TTU environmental health and safety (EH&S) officers, according to an interview transcript.
When Brown thought he was done, he set down the mortar and took off his goggles. Then he decided to give the compound one last stir. The mortar exploded in Brown’s hands. Brown “lost three digits on his left hand, severely lacerated his right hand, perforated his left eye, scratched his right eye and had superficial cuts to the parts of his body that were exposed,” says an investigation report prepared by Randy Nix, TTU’s EH&S director. The other student was not injured.
The students’ laboratory notebooks and the TTU police and EH&S investigation reports, along with related interview transcripts and summaries, collectively reveal a lack of attention to safety at TTU at all levels—lab, department, and university. The incident has prompted changes in TTU’s laboratory safety program as well as new oversight of laboratories funded by the Department of Homeland Security (DHS), which funded Brown’s research through Northeastern University’s Center of Excellence for Awareness & Localization of Explosives-Related Threats (ALERT).
“This was a very unfortunate and unnecessary accident that could have resulted in loss of life very easily,” says T. Taylor Eighmy, a civil engineer and TTU’s vice president of research. “I think that the graduate student in question has culpability here of carelessness in the lab.” And beyond that, at the department and institutional level, “the culture around safety was just not as prevalent as it should have been,” Eighmy says.
Chemical engineering professor Brandon Weeks told police that the Hope-Weeks lab was working on a project to characterize energetic compounds that could be used to produce improvised explosives, according to the TTU police report, one of several documents obtained by C&EN through a public records request. Results from the research were to be used by collaborators to develop new detection and mitigation techniques for the explosives. Weeks is the lead principal investigator for the effort, and Hope-Weeks is a co-principal investigator.
Brown was training the other student to take over his project in anticipation of Brown’s graduation, according to the EH&S interview transcript. Brown’s laboratory notebook provides no detail about what exactly the two were doing in the lab on the day of the incident. Brown used 14 pages in his lab notebook to document his lab work from Sept. 9, 2009, through the date of the incident. During that time, the notebook includes seminar notes, other notes seemingly unrelated to his research, and only vague descriptions of experimental work: One apparent synthesis is documented in an undated entry simply as “Ni(NO3)2 + hydrazine / 10 g / purple ppt forms immediately / also an exothermic rxn.” The other student’s “notebook” is a typed summary of reaction protocols and observations, also without dates. TTU has declined to identify the other student because of student privacy laws; Brown’s identity became public at the time of the incident.
Brown told Nix and TTU laboratory safety specialist Jared Martin that he and the other student were making “cobalt perchlorate hydrazinate,” the interview transcript
says. But on the day of the incident, the other student told police that they were working with nickel hydrazine perchlorate and told Martin that the compound they were working with was blue or purple—a color consistent with his notebook description of nickel hydrazine perchlorate. Hope-Weeks believes the students made nickel hydrazine perchlorate, “but due to conflicting reports and the fact that the compound was destroyed in the explosion and subsequent emergency disposal, she can’t be absolutely certain,” says Alice M. Young, TTU faculty fellow for research integrity and a pharmacology professor. Hope-Weeks did not respond to a C&EN interview request.
Chemical Hygiene Plan Violations
An internal investigation determined that Texas Tech University violated many of its own policies and procedures. Some of the findings were as follows:
The chemistry department did not
• Implement university health and safety policies
• Maintain a current list of OSHA-regulated substances
• Ensure that personal protective equipment was worn in laboratories
• Appoint a department chemical hygiene coordinator
• Train employees
• Maintain availability of material safety data sheets
• Develop a department-specific CHP (which led to other violations, including a lack of standard operating procedures and policies for reducing chemical exposure) The principal investigators did not
• Ensure that containers were properly labeled
• Perform a hazard determination of chemicals generated in the lab
• Ensure that workers knew and followed chemical hygiene rules
• Prepare written procedures for use of carcinogens
• Conduct regular chemical hygiene and housekeeping inspections
• Ensure that adequate facilities and training were available for use of lab materials TTU EH&S investigation interviews with other researchers who worked in the lab indicate that Brown’s labmates were disturbed by his conduct in the lab prior to the incident. His space was disorganized, items were not labeled, and “there had been conflicts over work space, cleanliness of the lab and use of chemicals,” one researcher told the investigators.
Another researcher told EH&S investigators that Brown started scaling up syntheses in June 2009, first to 1 to 3 g and then to 5 g. The researcher told Brown the scale-up was inappropriate; Brown reportedly responded that things were “just fine.” The researcher apparently did not report the scale-up to either Weeks or Hope-Weeks.
Brown later told investigators that he scaled up syntheses because he was concerned about batch-to-batch consistency.
“There was no logical reason for anyone involved in the research to utilize 10 grams of the substance for workbench testing,” Weeks told police. Under typical circumstances, 50 to 100 mg of a compound would be enough to fully characterize material with methods such as spark tests, flame tests, pressure hammer tests, and infrared spectroscopy, the police report says.
The instrumentation for some of those tests was in other buildings on campus. Brown transported as much as “several grams of compounds” at a time in glass vials in a backpack or coat pocket, a researcher who helped Brown told EH&S investigators. Brown “was told that a metal container would be better for the transport, but he continued to bring them in a glass vial,” the researcher said.
Weeks also told police that a student reported to him that Brown “would often avoid necessary steps to characterize compounds in order to save time,” the police report says.
None of the researchers interviewed by EH&S officials, including Brown and the student he was training, reported receiving either general safety training or specific instruction on how to handle energetic materials. The Hope-Weeks lab had neither blast shields nor a safe in which to store energetic materials, Eighmy says.
As for communication with Hope-Weeks, Brown told investigators that he would see her at weekly group meetings or go to her office to ask questions. Hope-Weeks told EH&S investigators that she assumed the students were synthesizing compounds in the quantities she told them to make—50 to 100 mg—and that she never checked on the amounts.
After the incident, personnel from the Lubbock County Sheriff’s Office Bomb Squad and the Bureau of Alcohol, Tobacco, Firearms & Explosives removed several vials of material from Brown’s home. The containers were largely unlabeled, except for one marked “TATP,” most likely for triacetone triperoxide. The bomb squad destroyed the items. Brown later told Nix and Martin that he brought vials home from the lab because he absent-mindedly left them in his pockets.
A further search of the Hope-Weeks lab turned up additional nickel hydrazine perchlorate “in both powder and liquid form in several places around the laboratory, with a number of the containers thought to be in various stages of production,” the police report says. Other powders and liquids found in the lab could not be identified because of improper labeling. Everything was removed and destroyed by bomb squad personnel.
Brown is now recovering from his injuries and is writing his dissertation, according to a TTU press release.
C&EN provided the TTU documents to several energetic materials experts to get their input on the incident.
“In light of the disregard for housekeeping and a cluttered work space, the lack of hazard-specific training, and the lack of direct supervision by experienced scientists, this research group was fortunate not to have had an incident earlier,” says Keith Butler, chief chemist at ammunition manufacturer American Ordnance.
“What appears to have happened was that students got complacent because they didn’t have any accidents and started scaling up without the knowledge of the professors,” says Charles A. Wight, dean of the graduate school and a chemistry professor at the University of Utah. “You need to have enough one-on-one training to make sure that doesn’t happen.”
With regard to training, “In laboratories that routinely synthesize and characterize novel explosive compounds, it is a general practice to evaluate new researchers by assigning them tasks with less sensitive, well-characterized explosives,” Butler says. Researchers who show a lack of respect for the compounds or lack the skills to manipulate them are given other projects or dismissed. Researchers who demonstrate proficiency are allowed to work with increasingly hazardous materials, he says.
Even after researchers demonstrate proficiency, however, the first rule of handling energetic materials is to keep quantities low, says Michael A. Hiskey, who formerly synthesized explosives at Los Alamos National Laboratory (LANL) and now runs pyrotechnics company DMD Systems. At LANL, in a dedicated energetic materials facility, “I wouldn’t have been allowed to make more than 0.5 g,” Hiskey says, adding that safety goggles and blast shields were used at all times. In Wight’s group at Utah, the limit for sensitive explosives is 10 mg.
Energetic materials experts also say that peer review is common in labs synthesizing particularly dangerous materials. “The worker would write up the proposed reaction, and another approved worker would review the work with special emphasis on safety,” says James R. Stine, a former high-energy-explosives group leader at LANL who is now retired.
The experts further highlight the need to fully characterize energetic materials, especially if reactions are scaled up. “Inorganic synthesis can be straightforward, but sometimes there are side reactions,” Butler says. The lumps that Brown was trying to break up “may have been contaminated with impurities that showed up in a 5- or
10-g batch that didn’t show up in 100 mg,” he says. Alternatively, the lumps could have contained unreacted perchlorate or may have been a different, more hazardous crystal form of the intended compound. Lead azide, for example, has one crystal form that is fairly stable and another that is very dangerous, Butler says. He would have separated the lumps from the larger sample and characterized them independently instead of trying to mix them in.
As for transporting energetic materials, Lawrence Livermore National Laboratory (LLNL) requires that small containers of samples less than 10 mg each must be packaged inside a carton or box that is marked as containing explosives, says lab spokeswoman Anne M. Stark. For quantities greater than 10 mg, samples must be packaged inside an ammunition can, with additional specifications for quantities between 300 mg and 2 g. People transporting explosives must have training to handle the materials and must hand-carry the containers or place them in a government vehicle, Stark says.