#Chemsafety at #ACSSanDiego
Aug22

#Chemsafety at #ACSSanDiego

Here’s what’s planned for chemical and laboratory safety at the ACS National Meeting in San Diego, which starts on Sunday. You can also take advantage of the Division of Chemical Health & Safety’s printer-friendly CHAS-At-A-Glance. Sunday, Aug. 25 Committee on Chemical Safety Open and Executive Subcommittee Meeting, 7:00–10:00 am, Marriott Marquis San Diego Marina, Marina Ballroom Salon GDivision of Chemical Health and Safety Executive Committee Meeting (agenda book here), 10:30 a.m.–1:30 pm, Marriott Marquis San Diego Marina, Marina Ballroom Salon G Division of Chemical Health and Safety Awards, 1:30 p.m.–4:45 p.m., Marriott Marquis San Diego Marina, Rancho Santa Fe 3 (CHAS, PROF)Workshop: Developing Graduate Student Leadership Skills in Laboratory Safety, 3:00-6:00 p.m., Hilton San Diego Bayfront, Aqua 313Division of Chemical Education Safety Committee Meeting, 5:15-6:45 p.m., Marriott Marquis San Diego Marina, Del Mar Monday, Aug. 26 Connecting Professionalism, Safety and Ethics: Opportunities and Challenges, 8:30-11:30 a.m., Marriott Marquis San Diego Marina, Rancho Santa Fe 3 (CHAS, CINF)Academic Lab Safety, 8:30 a.m.-12:10 p.m., Marriott Marquis San Diego Marina, Carlsbad (CHED, CCS, CHAS)Connecting Professionalism, Safety and Ethics: Opportunities and Challenges, 1:30-3:15 p.m., Marriott Marquis San Diego Marina, Rancho Santa Fe 3 (CHAS, CINF)Academic Lab Safety, 1:30-4:40 p.m., Marriott Marquis San Diego Marina, Carlsbad (CHED, CCS, CHAS)Division of Chemical Health and Safety 40th Anniversary Symposium, 3:30-5:15 p.m., Marriott Marquis San Diego Marina, Rancho Santa Fe 3 (CHAS)Social hour networking reception, 6:30-8:00 p.m., Hilton San Diego Bayfront, Indigo Ballroom AE (cosponsored by Industry Member Programs, the Division of Chemical Health and Safety, Corporation Associates, Division of Business Development and Management, and Small Chemical Businesses)Sci-Mix, 8:00-10:00 p.m., San Diego Convention Center, Exhibit Hall B Tuesday, Aug. 27 Connecting Safety, Education, Training and Productivity in Analytical Laboratories, 8:00-10:50 a.m., Marriott Marquis San Diego Marina, Torrey Pines 2 (ANYL, CHAS, CCS, CINF, PRES)Chemistry of Disasters, 1:00-5:20 p.m., San Diego Convention Center, Room 5A (PRES, CHAS, CCS, I&EC) Wednesday, Aug. 28 Graduate Students Perspective on Safety Education, 8:30-11:45 a.m., Marriott Marquis San Diego Marina, Rancho Santa Fe 3 (CHAS, CCS) What’s C&EN up to at the meeting? Check out our events here. Follow us on Twitter or Facebook. And sign up for C&EN’s daily Inside #ACSSanDiego newsletter to get the meeting’s essential chemistry...

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Don’t mix sodium hydride with polar aprotic solvents
Aug21

Don’t mix sodium hydride with polar aprotic solvents

Combining sodium hydride with some solvents can be a bad idea, as a group of researchers from Corteva Agriscience and Dow Chemical remind the chemistry community in Organic Process Research & Development ,(2019, DOI: 10.1021/acs.oprd.9b00276). An intact calorimetry cell (left) and a ruptured cell the authors used to study the explosive risk of NaH in DMSO. These cells typically rupture at pressures in excess of 1,000 bar. Credit: Org. Process Res. Dev. Reports of explosions from combining NaH with a polar aprotic solvent such as dimethyl sulfoxide (DMSO), N,N-dimethylformamide (DMF), and N,N-dimethylacetamide (DMAc) go back at least to 1966: Sodium hydride-DMSO mixture explodesA violent pressure explosion occurred during the preparation of methylsulfinyl carbanion by a scheme involving the addition of sodium hydride to an excess of dimethyl sulfoxide. Scientists at the Cancer Chemotherapy Research Department of Mount Zion Hospital and Medical Center (Palo Alto, Calif.) were scaling up a seemingly effective method of C-methylating heteroaromatics [J. Org. Chem., 31, 248 (1966)]. When the CCR chemists tried a mole ratio DMSO (2.15) : sodium hydride (0.41) : isoquinoline (0.40), the methylation was incomplete. And it did not explode.In the next experiment, 4.5 moles of sodium hydride were added, in five portions during three hours, to 18.4 moles of DMSO. The reaction was kept at 70 °C. and mechanically stirred. After an hour, solution was complete. Then, however, the temperature increased slightly and a greenish solid began to separate. The reaction was cooled, but the temperature rose sharply and after a few seconds the explosion occurred. A noxious gas filled the laboratory and a water-soluble, viscous, polymerlike material coated the hood and its contents.Frederick A. French of the Cancer Chemotherapy laboratory says that he knows of no previous mishaps with solutions of alkaline reagents in DMSO. However, the hazards from acidogenic reagents, such as acid chlorides and halomethyl ketones, and DMSO are well known, he notes.C&EN April 11, 1966, page 48 From C&EN’s story about the new OPR&D paper: Yang and coworkers also investigated the chemistry that makes these combinations unsafe. Yang says that radical reactions between the base and the solvents can generate gases, including dimethylsulfide and ethylene in the case of NaH added to DMSO. . . . [Yang] points out that there are alternatives that can perform the same chemistry, although there is no combination that can be universally applied as a substitute. Tetrahydrofuran could be used as a solvent with NaH, and there are alternative bases, like alkoxides and hydroxides. “But scientists have to understand the stability of these bases with the solvents as well,” Yang says. C&EN Aug. 19,...

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Liquid nitrogen calamities
Mar28

Liquid nitrogen calamities

Credit: Shutterstock Via @sarahdcady on Twitter, some liquid nitrogen stories from 2006. One wasn’t quite a calamity–but it easily could have been. Down the stairs at the University of California, Berkeley: Yesterday the LeConte elevator was out of order, which for most of us would have meant taking the long way around. However, one undergrad, tasked with transporting a full 230 L dewar, simply decided to take the stairs.At about 80% the density of water, 230 liters of liquid nitrogen weighs about 400 pounds, not counting the additional weight of the steel vessel containing it. When rolled onto the stairs, the dewar promptly tipped over and plummeted downward on its side, knocking deep gouges in the marble steps and dragging along the unfortunate student, who inexplicably held on as his cargo began to tumble. Miraculously both student and dewar arrived at the landing without rupturing, but the dewar was still on its side and pressure was building up.This was the situation when we got the frantic call from the building manager; once enough of us arrived at the scene we were able to pull the dewar upright and release the pressure. This averted any imminent explosion, but now we had a different problem: 400 pounds of liquid nitrogen stranded on a landing between the ground and first floors. Suggestions were floated including emptying the nitrogen out the nearby window, but ultimately we found another dewar which was wheeled to the top of the stairs on the first floor, and the nitrogen was transferred there through a long hose. The empty dewar was then carried up the stairs, a task requiring four men and gouging new (but shallower) grooves in the staircase. When metal plugs replaced pressure relief and rupture disks at Texas A&M University: The cylinder had been standing at one end of a ~20′ x 40′ laboratory on the second floor of the chemistry building. It was on a tile covered 4-6″ thick concrete floor, directly over a reinforced concrete beam. The explosion blew all of the tile off of the floor for a 5′ radius around the tank turning the tile into quarter sized pieces of shrapnel that embedded themselves in the walls and doors of the lab. The blast cracked the floor but due to the presence of the supporting beam, which shattered, the floor held. Since the floor held the force of the explosion was directed upward and propelled the cylinder, sans bottom, through the concrete ceiling of the lab into the mechanical room above. It struck two 3 inch water mains and drove them and the electrical wiring above them into the concrete roof...

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Send your favorite chemist a #labsafety valentine
Feb14

Send your favorite chemist a #labsafety valentine

University of California, San Francisco, chemical hygiene officer Caroline Hedge started a thread on lab safety valentines on Twitter, and they were too clever not to share. 💌 @CM_Hedge Roses are red Fire is too Review the SOP Especially if you’re new 🤢 @CM_Hedge Your eyes are red You don’t feel good Get off the bench And work in the hood 👀 @AlexFGoldberg my eyes are itchy gave them a rub oh no it’s burning didn’t take off my glub 😧 @arndt_eric Glassware is dirty Nochromix is bubblin’ Spilt some on my arm Now my lab coat is darkenin’ ❤️❤️ @olie_chem Roses are red Violets are blue We have a double glovebox So you can work too 🔥 @difluorine Roses are red Fire is blue If you happen to be burning Pb, Ta, Sn, Nb, Ce, Cs, or maybe Cu 🔥 @CM_Hedge Roses are red Some metals aren’t mellow If they catch fire Use the class D, its yellow 🔥 @ChemistryCayk Roses are red Some stuff’s pyrophoric And if it ignites We ought to run for it 😀 @CM_Hedge Roses are red Nomex lab coats are blue Wear proper PPE It’s the right thing to...

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10 years ago, Sheri Sangji died following a lab fire
Jan16

10 years ago, Sheri Sangji died following a lab fire

Today is the 10th anniversary of Sheharbano (Sheri) Sangji’s death from injuries sustained in a laboratory fire at the University of California, Los Angeles. From C&EN: Her death pushed some chemists to try to improve academic lab safety culture to prevent similar accidents at their own institutions and beyond. C&EN asked scientists from all corners of the chemistry community to describe their efforts. Read on for their strategies, including incorporating safety into chemistry education, improving training, and developing resources to help people work in a safer manner. Yet large-scale, systemic change remains elusive, as demonstrated by grievous incidents in the decade since Sangji’s death. Postdoctoral researcher Meng Xiangjian died in a hydrogen explosion at Tsinghua University in 2015. Graduate student Preston Brown lost three fingers and damaged his eyes in a nickel hydrazine perchlorate explosion at Texas Tech University in 2010. And postdoc Thea Ekins-Coward lost one of her arms in a hydrogen-oxygen gas mixture explosion at the University of Hawaii at Manoa in 2016. Adding to that list, in early December one researcher was killed and three others were injured in what seems to have been an explosion of a hydrogen-oxygen gas mixture at the Indian Institute of Science’s Laboratory for Hypersonic and Shock Wave Research. A few weeks later, three students died in an explosion involving sewage treatment experiments at Beijing Jiaotong University, according to local news reports. And those are just the incidents that C&EN knows about that involved deaths or significant permanent injuries. Many others had milder consequences, though they could’ve easily been worse. To learn more about how to improve laboratory safety culture, particularly in academic research labs, read C&EN’s...

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