This week’s Chemical & Engineering News has an amazing article on the recent tragic death of Sheharbano (Sheri) Sangji, a research assistant in the lab of Professor Patrick Harran at UCLA. If you have not read it, I highly recommend that you do.
This incident in particular has brought academic labs under the spotlight with regard to their attitude to safe practices in the lab. Many of my colleagues have war stories from their times in academia, talking about procedures that would not be tolerated in an industrial setting. Occasionally people talk about how it was because we were young and inexperienced and sometimes it is about how much money that there is to spend on safety, but generally I think most feel it is about getting results from their graduate students in a short time frame. It is in the interest of both student and professor that the work being done produces papers. The result: long hours and lax safety practices.
In some ways, though, it is a surprise that Sheri’s accident involved t-butyl lithium (tBuLi), which is a highly pyrophoric material (meaning it spontaneously catches fire in the air). When handling such a known danger as this, most people would take extra precaution, treating it with the proverbial kid gloves. This was (as far as we can tell from the investigation done by C&E News) only the second time she had used this material – certainly not a case of overly familiarity.
My personal theory is that Sheri treated the larger scale reaction as she had her previous experiment. She figured that she could just use a syringe to deliver the t-BuLi to the reaction, as she had done before. OK, it would take several aliquots, but that would not be a problem. It would save her having to use a cannula and pressure to push the reagent into another flask. I expect the first aliquot went relatively smoothly, but when she went to do that again, the syringe plunger became more difficult to pull out, then it gave suddenly and pulled all the way out.
This is often an issue when scaling up a reaction. What works on with only a small amount suddenly does not work with a much larger amount. The slightly warm reaction on 10 mL scale becomes a spontaneous reflux on 100 mL scale. The reaction suddenly doesn’t stir so well. Or, as in this case, the volume of reagents overwhelms the way that you have to deliver it.
I think I am personally so interested in this story because it is, to coin a phrase, happening where I live, that is in the laboratory, doing reactions and using potentially dangerous reagents. I can almost imagine the thought processes of the young chemist, as she tries to deal with the unfolding situation. You do not make good decisions when you are trying to improvize, you jury-rig and make do. Only by looking at the procedure before entering the lab and thinking “what is the best way to do this?” and “what can go wrong?” and “what will I do if it does?” can chemistry be safely be done, without needless loss of young lives.