Trimethylsilyldiazomethane safety under investigation
May12

Trimethylsilyldiazomethane safety under investigation

Back in 2008, two chemists died after exposure to trimethylsilyldiazomethane (TMSD): Jason Siddell, age 24 and employed at Gelest, and Roland Daigle, age 46 and employed at Sepracor Canada (now Sunovion Pharmaceuticals Canada). This year, the U.S. National Toxicology Program (NTP) is finally studying the compound’s toxicity. The U.S. Occupational Safety & Health Administration (OSHA) investigated Siddell’s death. OSHA cited Gelest for violating hazard communication standards and fined the company $1,500. Daigle’s case was investigated by the Nova Scotia Department of Labour & Advanced Education and the province filed five charges against Sepracor Canada. The company agreed to a deal that involved pleading guilty to one charge of failing to provide proper workplace ventilation and a $47,000 fine. A bit more detail about what happened to Daigle can be found in a case report published in Clin. Toxicol. 2009, DOI: 10.1080/15563650903076924 (abstract 48). U.S. OSHA also nominated TMSD for study by NTP. As Derek Lowe has noted, many people believe TMSD is safer than diazomethane. TMSD is safer if you just consider explosive properties. But toxicologically, TMSD may be just as poisonous as diazomethane. The toxicology studies will say for sure. NTP is part of the National Institute of Environmental Health Sciences, and according to institute spokeswoman Robin Mackar, NTP has developed and validated an inhalation exposure system and plans to start acute toxicity studies in the fall. “The primary focus of these studies is to evaluate potential pulmonary toxicity, but other tissues will be assessed,” Mackar adds. “Once the research and analysis is completed, the results will be published in a peer-reviewed journal...

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Diazomethane without distillation
Mar29

Diazomethane without distillation

A quick note on something else in the magazine this week: A story by Beth Halford on a new way to make diazomethane in situ, without distillation. As Beth notes, diazomethane is both explosive and toxic, and the common alternative trimethylsilyldiazomethane is less explosive but probably NOT less toxic—two chemists died in 2008 from trimethylsilyldiazomethane exposure. Anything that makes the reagents safer to handle seems like a definite plus. Go...

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OPRD safety issue
Dec09

OPRD safety issue

‘Tis the season…for Organic Process Research & Development‘s annual “Safety Of Chemical Processes” section. The issue contains literature highlights, summarized as Safety Notables, as well as original papers. First, though, comes an editorial by editor Trevor Laird, with a caution on including needed information in documents versus being overly comprehensive: I recently reviewed a batch record for a simple process (add reagents, heat, monitor until complete, cool, quench, filter, and dry) and was surprised at the length of the document—over 300 pages. There was no doubt that the document was extremely comprehensive, but the question I ask is, Was it likely to be read by the process operator in the amount of detail that was provided? It was extremely complex, and I felt that any safety messages would have been lost in all the detail. In fact, with a document of such complexity I suspected that the operator would be more likely to make mistakes through having misunderstood what he was supposed to do. Surely these batch records can be simplified so that the operator’s instructions are clear. I must admit that I found it difficult to read the entire document and to find the information that I wanted. Topics in the Safety Notables: Toxic tips, pointing to William Luttrell‘s organic molecule reviews in the Journal of Chemical Health & Safety Expansion of a solvent selection guide Workplace safety Synthesis of energetic materials Dust explosion hazards Learning from history Safer reagents and reagent handling A safe and practical procedure for difluoromethylation Process hazard analysis Deciphering the MSDS Comparison of two methods for self-accelerating decomposition temperature (SADT) determination Safety issues with nanomaterials Inherently safer technology Safe, scalable nitric acid oxidation Chemical safety alert, pointing to the C&EN safety letter from Northwestern’s Joseph Hupp and SonBinh Nguyen regarding an explosion involving aqueous hydrogen peroxide and acetic anhydride Flashpoints Continuous process for alkene ozonolysis Investigating exothermic activity Development of a safe and practical N-oxidation procedure Drum pressurization Trimethylsilyldiazomethane: A safe nonexplosive, cost-effective, and less toxic reagent for phenol derivatization in GC applications. I’m going to quibble with this, because after looking into two deaths in 2008 from TMSD exposure, it’s not at all clear to me that it is less toxic than diazomethane. I’ve requested the paper from the corresponding author–I’m curious to see what their evidence is for that assertion. Process safety and the human factor A safe and practical procedure for global deprotection of oligoribonucleotides Mining the web for safety information Full papers, communications, and technical notes: Determination of Accurate Specific Heat Capacities of Liquids in a Reaction Calorimeter, by Statistical Design (from Sanofi-Aventis) Design and Scale-Up of Diels–Alder Reactions for...

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Sepracor pleads “not guilty” in lab death
Sep15

Sepracor pleads “not guilty” in lab death

Two years ago next month, Sepracor Canada chemist Roland Daigle died at age 46 after being exposed to trimethylsilyldiazomethane. According to news reports, Daigle was inexplicably working in a lab when the fume hoods were down because of roof work. The incident was investigated by the Occupational Health & Safety (OHS) Division of the Nova Scotia Department of Labour & Workforce Development. Last spring, the province brought five charges against the company, which is now owned by Dainippon Sumitomo Pharma. Yesterday, Sepracor Canada pleaded not guilty to the charges. The trial is scheduled for May, 2011, although Lynda MacDonald, Daigle’s sister, says that the family was told to expect delays. I’ve listed the charges in full after the break, since those are the most complete information I have about what happened. Jim LeBlanc, executive director of OHS, says that the agency cannot release its investigation report, even in response to a public records request, until court proceedings are complete. Sepracor Canada (Nova Scotia) Limited, 24 Ivey Lane, Windsor, Nova Scotia, as an employer, failed to ensure that the employees, and in particular the supervisors and foremen, are made familiar with health or safety hazards that may be met by them at the workplace, as prescribed by Subsection 13(1)(d) of the Occupational Health and Safety Act, S.N.S. 1996, c.7, and did thereby commit an offence contrary to Subsection 13(1)(d) and subsection 74(1)(a) of the said Act. Particulars: The employer, Sepracor Canada (Nova Scotia) Limited failed to ensure all employees of the Quality Control Lab, were made aware of the hazards associated with or resulting from conducting Sepracor’s test method 00365 (d-malic acid test). Consequently, when a chemical odour was detected in the Quality Control Laboratory on or about October 7, 2008, employees failed to appropriately recognize the hazard and initiate emergency procedures. Sepracor Canada (Nova Scotia) Limited, 24 Ivey Lane, Windsor, Nova Scotia, as an employer, failed to ensure that adequate personal protective equipment or devices required for an assigned task are used, based on the nature of the task, the location and conditions of the workplace and any hazards that may effect the health and safety of people in the workplace, as prescribed by Subsection 9(1) of the Occupational Safety General Regulations made pursuant to the Occupational Health and Safety Act S.N.S. 1996, c.7, and did thereby commit an offence contrary to Section 9(1) of the Occupational Safety General Regulations and Subsection 74(1)(a) of the Occupational Health and Safety Act. Particulars: The employer, Sepracor Canada (Nova Scotia) Limited, failed to ensure the use of adequate personal protective equipment by employees working in the Quality Control Lab on or about October...

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