“The kind of whistling you would rather not hear in a chemistry lab”
Sep22

“The kind of whistling you would rather not hear in a chemistry lab”

From a reddit forum, a rather dramatic tale of what happens when nitric acid and ethanol are combined in a waste container: There were no empty nitric bottle in lab so rather than go get a new one 4 floors down, I grabbed a common use waste bottle. These are 4 liter glass bottles with a screw on cap.6 Usually they are used to collect organic waste, brought to a central facility where they are emptied and then thoroughly cleaned. University protocol is that they are first cleaned with ethanol, then water. The idea is that the only remnants in these bottles should be water. I happened to pick a bottle that had not been washed with water. Knowing that nitric acid was dangerous, I visually checked the bottle to make sure it was empty. There was a little bit of water (or so I thought)7 in the bottom, which did not concern me because nitric acid and water are fine to mix.8 I proceeded to clean my glass using a total of 30-50 mL of nitric acid, which I disposed of in the waste container. Knowing that nitric acid could react with organics, I left the waste bottle un-capped in my fumehood for about 60 seconds after I put the nitric in. Seeing no reaction, I then capped the waste bottle loosely. This probably saved me a trip to the hospital. Now, the astute chemist reading this may have figured out what happened next.9 Nitric acid and ethanol (remember this bottle was supposed to be washed with water, but never was) react very violently to produce heat and a large amount of gas. This reaction has an incubation time of a few minutes before it really kicks in. So 20 or so seconds after capping this bottle, I hear an ominous whistling sound. The kind of whistling you would rather not hear in a chemistry lab. I look at my fume hood and saw a very large and copious amount of brown gas (NOx) billowing out from my loosely fitted cap. As the whistling increased to a truly terrifying pitch, I had a few seconds to dive behind a wall before the waste bottle exploded with a force much larger than that mortar from the front page yesterday.10,11,12 Here I fucked up again as despite my 10 or so second lead time, I did not warn anyone that a glass shrapnel bomb was about to go off. I am so fucking lucky that no one decided to come around the corner at that moment. As the nitric acid tinged glass rained down upon me, my lab mates rushed...

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Waste explosion at Texas Tech
Feb26

Waste explosion at Texas Tech

On Feb. 2, a glass waste bottle exploded in a Texas Tech University teaching laboratory, injuring three undergraduate students and a graduate teaching assistant. TTU has nowposted its investigation results online. In short, a nitric acid wash step was eliminated from the lab but the written instructions were not revised (I don’t know how this was communicated–with a verbal “skip step X”?). Nitric acid waste then wound up in a bottle with methanol and dimethylglyoxime, reactions ensued, pressure built up, and the bottle exploded when a student later tried to open it. The good: “All students and personnel were wearing appropriate personal protective equipment including lab coats, safety goggles and gloves.” The bad: The waste bottle was labeled with HNO3, HCl, methanol, and dimethylglyoxime. Clearly the lesson is not getting through to people that you can’t mix nitric acid with organics. Also, people need to keep written procedures up to date. It’s not hard to see how a verbal instruction would get ignored in favor of what’s written down, not to mention what happens if the person who historically runs the lab is out sick or has left the department. TTU is surely not the only institution challenged by these things. I would also argue that TTU should be commended for continuing to make its incident information available so that others in the academic and chemistry communities can learn from the experience. TTU’s action items to move forward: 1. EH&S will be providing pressure relief caps to waste storage bottles that contain inorganic acid wastes. 2. Faculty, instructors and TA’s should communicate unique safety concerns at the beginning of teaching labs prior to any experiments. The safety concerns should reflect the hazards posed by that experiment. 3. Responsible individuals over teaching labs should revise their teaching procedures regularly and review for possible hazards that can be eliminated. Any additions or deletions should be reflected in handouts provided. If people could use nitric acid + organic solvent visual for training purposes, this YouTube video seems...

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Legacy samples yield headaches
Sep09

Legacy samples yield headaches

Several safety breaches involving pathogens have brought attention to the problem of legacy samples. Vials of smallpox dating to the 1950s were discovered in unsecured Food & Drug Administation labs on the National Institutes of Health campus in Bethesda, Md., earlier this summer. Then, last week, the Washington Post reported that NIH workers found ricin, the bacteria that cause plague, and other so-called “select agents” where they weren’t supposed to be. Meanwhile, FDA found staphylococcal enterotoxin in a lab that wasn’t supposed to handle it. Select agents are “biological agents and toxins have been determined to have the potential to pose a severe threat to both human and animal health, to plant health, or to animal and plant products,” according to the Centers for Disease Control & Prevention. There may be more coming: The White House Office of Science & Technology Policy has requested a safety stand-down in which government labs and nongovernment labs that receive federal funding are encouraged to do “an immediate sweep of their facilities that possess, use, or transfer human, animal, or plant infectious agent or toxin holdings to identify Biological Select Agents and Toxins (BSA) and ensure their proper registration, safe stewardship, and secure storage or disposal,” according to an Aug. 18 memo. An Aug. 27 NIH notice says that its labs are conducting inventories of infectious agents and toxins. I’m sure all scientists can imagine what may have happened here: Someone left without clearing their bench or their lab. Someone else took over. Instead of cleaning out, they pushed the samples to the back of the fridge or storage area. Repeat. But someone, someday has to deal with it. Last year, the University of California, Davis, chemistry department cleaned out more than 10,000 lb of hazardous waste that had accumulated over decades, department safety manager Debbie M. Decker said in a talk at the ACS Meeting in San Francisco last month. Potentially explosive compounds filled a roughly 10 ft3 bunker, and it took about six months to get everything removed from campus for disposal, Decker said. So far, no one at NIH has gotten ill from the old samples. Nor was anyone at UC Davis hurt. But was it worth the risk not to clean out samples, reagents, or solvents sooner? Even if you think you might use something someday, will you trust that it’s still good by then? Delaying disposal often just makes cleaning out more expensive, too, especially if you can no longer read a label or something becomes potentially explosive over time, such as with diethyl ether...

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Explosion at the University of Maryland
Sep29

Explosion at the University of Maryland

On Monday, an explosion occurred during an organic chemistry lab at the University of Maryland (UMD). The local fire department responded, reportedly sending “16 pieces of fire, EMS and Haz-Mat units and about 70 personnel” to the scene. Two students received first- and second-degree chemical burns and were taken to an area burn unit. UMD chemistry department chair Michael Doyle tells C&EN that: The evidence that I saw with the fire marshall was consistent with waste material (strong acids) being inappropriately added to an organic reagent bottle and not to a waste container. I believe that the lesson learned is the need to segregate reagents for a lab from the reagents being used. One of my colleagues notes that this is also a reason to be careful about reusing old reagent bottles as waste containers–current reagents and waste can be easily confused (although I don’t know if this was actually the situation at UMD). The fire department’s blog has more photos, although the post differs from Doyle on the cause of the...

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