The Sheri Sangji accident: The experimental details

Science has just published a summary of the report by California's Division of Occupational Safety and Health about the tragic accident involving Sheri Sangji and tert-butyl lithium. The summary is the most detailed description of the accident that I have seen so far and it makes it clear that there were at least four very significant violations of protocol during the experiment that Sangji was performing. These included:

1. Not wearing a lab coat and other appropriate safety gear.

2. Using a plastic syringe that by definition cannot be oven-baked to remove traces of moisture.

3. Using a syringe with a 2-inch needle that was about an order of magnitude shorter than the recommended length (1-2 ft.). This was a very significant safety breach since it would have required Sangji to tilt the bottle to extract the liquid, thus not only increasing the chances of a spill but also diminishing her general degree of control over the whole procedure.

4. Actually pulling the plunger back rather than let it be pushed by the inert nitrogen pressure from the bottle.

Of these four violations, only the first one can be easily assigned to Sangji herself since lab coats constitute a very general and well-known part of safety equipment. The others are specialized and specific to hazardous substances and their assignment is going to be much more ambiguous. The rub of the matter is going to be in finding out if these violations were the result of inappropriate or insufficient communication by the PI or an oversight on the part of Sangji herself.

From what I can tell, the report seems to lean toward the former possibility. One of the statements I found disturbing was Prof. Harran's admission that he "never discussed with Victim Sangji the risks associated with the tasks she was undertaking". Another important matter which I alluded to in a previous post was the responsibility of senior postdocs and graduate students in the lab, and the report provides a new twist to the issue that I hadn't seen before. Harran says that a postdoc in his group was supposed to train Sangji in the specifics of handling t-BuLi. The postdoc himself admits that he does not have specific recollection of providing "formal" training to Sangji. In addition Harran admits that he never confirmed whether the postdoc had in fact properly instructed Sangji in the use of the hazardous reagent. I would think that the relative apportioning of the blame between Harran and the postdoc is almost certainly going to be a focus during the trial.

None of this is too comforting and it certainly does not sound like it would make it easier for Harran to defend himself. And yet the sad fact of the matter is that this is how many labs around the world probably operate. The PI does not immerse himself in the minutiae of handling specific reagents and leaves it to the postdocs in the group. The postdoc or senior students in turn gingerly step into that notoriously gray area where it becomes difficult to say whether a particular degree of instruction was "sufficient" or not; for instance, was it enough for the postdoc to demonstrate the protocol once? How about twice? How about one actual demonstration followed by two pointed reminders?

These and other questions are almost certainly going to come up during the proceedings and their fuzzy, gray nature is going to make it difficult to assign blame. But the details of the report make it clear that somewhere, sometime, the crucial information undoubtedly slipped through the cracks. And even a clear admission of this fact may make practitioners around the world more vigilant and, one hopes, more humble.

The wrath of lithium

Mitch alerts us to this extremely tragic story where a UCLA lab assistant has succumbed to burns caused by t-butyl lithium:

A 23 year old female research associate/laboratory technician intended to add an (unknown) aliquot of 1.6 M t-bu-Li (in pentane) to a round bottom flask, placed in a dry ice/acetone bath. She had been employed in the lab for about 3 months. The incident occurred on Dec. 29, during the UCLA holiday shutdown between Christmas and New Years. Researchers are granted permission to work during the shut down for “critical research needs.” There were two post doctoral researchers working in the lab and the adjacent lab, with limited English proficiency.

The principal investigator had trained the employee to slightly pressurize the bottle (an ~ 250 ml Aldrich Sure Seal container) with Argon and withdraw the desired aliquot using a 60 ml syringe, fitted with a 20 gauge needle. The PI likes to use these particular syringes because they have a tight seal. There is no evidence that the employee used this method. Speculation: she may have just tried to pull up the aliquot in the syringe. Somehow, the syringe plunger popped out or was pulled out of the syringe barrel, splashing the employee with t-bu-Li and pentane. The mixture caught fire, upon contact with air. She was wearing nitrile gloves, safety glasses and synthetic sweater. She was not wearing a lab coat. The fire ignited the gloves and the sweater.

Six feet from the fume hood was an emergency shower. When the employee’s gloves and clothing caught fire, she ran from the area away from the shower. One of the post-docs used his lab coat to smother the flames. 911 was called. UCLA Fire Dept. and emergency medical, Los Angeles City Fire, and Los Angeles County Haz Mat. The EMTs put the employee in the safety shower for gross decon and then transported her to the ER. She’s currently in the Grossman burn unit in Sherman Oaks with second degree burns on her arms and third degree burns on her hands, a total of about 40% of her body. There was very little damage to the lab. Bill has not interviewed the employee.

I find it especially sad that she was doing a relatively routine procedure done in hundreds of labs, and was wearing gloves and safety goggles, even if not a lab coat. This sobering incident should remind us that for all that we jest about laboratory procedures and reagents, working in a lab should be a deadly serious activity. Sometimes the monotony blurs the line between casual protocol and hellishly serious work precautions.