Friday, May 8, 2009

"Expectation": more details emerge about the UCLA/Sheri Sangji case

Jyllian Kemsley's article in C&EN succinctly summarizes the state of play in the UCLA/Sheharbano "Sheri" Sangji case: the Cal/OSHA fines, the relative dissatisfaction of Naveen Sangji with the Cal/OSHA report and Neal Langerman's continued call for a revolution in academic lab safety.

Included in the article are a few quotes from Prof. Harran:
Sangji's supervisor, professor Patrick Harran, says that he did address the PPE issues with his group. "My expectation is that everyone is to wear a lab coat and wear protective gear on their eyes," he says, adding that a lab coat is specifically ordered for everyone who joins the group. He refused to speculate as to why Sangji was not wearing her coat on the day of the accident. The two postdoctoral researchers who were in the lab with her were both wearing their lab coats, Harran says. [later in the article...] Regarding Sangji's training to handle tert-butyllithium, "She was supervised by senior personnel in my lab and shown how to do this particular procedure. She repeated it successfully," Harran says.

Ah, expectations: I do not know Professor Harran's personal vocabulary choices -- what does the term "expectation" mean to him? To me, it is a typical statement from a chemistry professor, much like he would expect a graduate student to keep a current notebook or to save their NMRs. It's quite possible that "expectation" is a stronger word to him -- we'll never know. 
A couple of questions: did Professor Harran ever express these expectations? Did he ever remind, hector or reprimand a graduate student or postdoc for lack of PPE? I frankly doubt it; most chemistry professors don't. They assume (and perhaps rightly so) that their graduate students will do what they think is necessary to keep themselves alive and standing at their hood... and the buck is thusly passed. 

Again with the labmates: Professor Harran notes that the postdocs were wearing their lab coats, but Ms. Sangji was not. Why didn't they say something? If I was a postdoc (and I have been) and coworker was starting up a larger scale tBuLi reaction in the hood next to mine without their lab coat, I might have expressed some concern (understatement?)
I beg of you, fellow chemists: be like Kyle (scroll down) and don't be afraid to call out your lab mates if they're being unsafe. Yeah, it might make you the lab jerk, but it'll keep someone safe -- trust me. 

What do you mean by success?: Professor Harran notes that Ms. Sangji completed the reaction before successfully. First of all, what does "successfully" mean? Does it mean that she performed the reaction safely or that the yield was equally high? I am curious to know the answer to that. 

It's all about scale: On what scale was her successful first reaction performed on? If my calculations are correct, the fatal reaction was performed on ~17 mmol scale (34 mmol of tBuLi, 2.0 equivs of tBuLi to one equiv. starting material (assuming Li-X exchange reaction)). This is not, repeat, not a trivial amount of starting material in a total synthesis-type lab, folks. Think of it this way -- if the molecular weight of her starting material was a low-to-average 250, that's 4.25 grams of starting material. It would be interesting to know the exact reaction Ms. Sangji was performing -- like many things about this case, this is just one of those details that will never see the light of day. 

Allow me to speculate and pontificate a little here: Scaleup is one of the trickiest parts of reaction chemistry. I speculate that both Professor Harran and Ms. Sangji made a crucial mistake: that if a reaction goes fine on 1 gram, it'll go fine on 4 grams (or 10 grams or 20 grams.) I've heard that you have to readjust your reaction conditions every 4X increase in scale -- I suspect that this was one of the hidden issues that was unaddressed before Ms. Sangji ran this reaction. If (and only IF) this was a scale-up of a previously successful smaller reaction, then I suspect that this may have been her first time using one of the monster 60 mL syringes. 

3 comments:

  1. As lab safety concerns all scientists, I thought this might be of interest to the readers on this blog.

    The following is a petition that Sheri’s friends set up to try and push for an investigation by the DA.

    Its been less than three days and there are already 725 signatures. Take a look for the other side of the story.
    http://www.thepetitionsite.com/1/sherisangji

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  2. There is nothing wrong with pointing out unsafe practices in a lab. Indeed, I not only teach grad students to look out for each other, I tell them to thank anyone who points out something they are doing that is dangerous.

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  3. I was cleaning glassware in a chromic acid/glacial sulfuric acid bath warmed on a pair of hot plates while working as an undergraduate assistant in the Chemistry Department at UCLA in 1971. This was a lab of Professor Willard Libby, and we were studying radiation chemistry of nucleic acids. The glass (not pyrex?) vat cracked open under uneven heating by the hot plates and I was immediately doused! I was working in a hood with a lab coat. I slipped, hit the floor and cut open my wrist. The grad student Saul Alkaitis saw this and immediately threw me in the safety shower. My clothes disintigrated and the laceration needed 4 or 5 sutures. I escaped serious injury. I do not recall much safety training...38 years ago.

    CGW, MD

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