As her tutors had said, there were two signs of a good alchemist: the Athletic and the Intellectual. A good alchemist of the first sort was someone who could leap over the bench and be on the far side of a safely thick wall in three seconds, and a good alchemist of the second sort was someone who knew exactly when to do this.
- Feet of Clay, by Terry Pratchett
I read the above while home sick today. It made me laugh. It also sent me right back to graduate school, and working in a synthetic lab. The above statement is as true of modern-day lab rats as it ever was of their medieval ancestors. Graduate school in chemistry requires a complicated mixture of scholarship, mechanical engineering, self-preservation, and pure luck.
I know of at least one student that reenacted the above scenario quite literally. After squirting a syringe full of organolithium reagent into a flask containing a halogenated solvent, something about the initial reaction told him what a colossal error he had made. He actually had time to slam the sash of the fume hood down and duck below bench level before the explosion. File that under both ’self-preservation’ and ‘pure luck’.
In our labs, almost everything we worked on was either water-sensitive, oxygen-sensitive, or both. In order to do synthetic reactions, in addition to being highly purified, our solvents had to be scrupulously dry and air-free. So we had a whole row of glass stills along one windowsill, kept under flowing nitrogen gas. Toluene, ethyl ether, tetrahydrofuran, all sitting over some agent that would react with any water or oxygen in the solvent. In some cases that was sodium metal, in others, an alloy of sodium and potassium. In every case, however, it was something highly reactive. After all it had to be, in order to do the job.
Take the sodium/potassium alloy. The NaK alloy was a molten pool at the bottom of the still. NaK is pyrophoric, so any exposure to the air would ignite it. Mind you, it’s sitting in about a liter of flammable solvent, so if the (glass) still breaks during reflux, chances are you will have a large fireball. And God forbid you pour water on that fire, because NaK explodes on contact with water. That rules out a CO2 extinguisher as well, because you know that white cloud they comes out of CO2 extinguishers? That’s condensed water vapor. Ba-Boom.
And this is just one still, in a row of seven or so, each having their own personal flavor of explosive hazard. We had a great, big, heavy Metal-X fire extinguisher at the door to the lab, so that if we had an alkali metal fire, it could be used to put it out. That is, if you could lift it. And if you were inclined to stick around long enough. However, the grim scenario of a still explosion was a frequent topic of beer-soaked conversation, and all of us grad students in the group had made an informal agreement that should any of the stills go up, we were out the door. We figured it would be fun to watch the third floor get blown out from the perspective of the street level. It was bound to be more entertaining than trying to put it out.
And we were just one research group, out of many. The guys next door worked with phosphine compounds that literally burst into flame when you took them out of the glove box. They had a metal trash can right outside the airlock to sweep Kimwipes and weighing pans into. That way, they could burn themselves out fairly harmlessly.
How does anyone end up doing something so foolhardy? And doing it so casually? Well, it’s like the frog in a pot of boiling water. The heat gets turned up gradually. You start out doing titrations with acids and bases. Then you start doing experiments that involve open flame. There’s a quantum leap in potential hazards when you start doing organic chemistry. By the time you are halfway through graduate school you are more or less inured to the constant threat of physical harm. You’ve gotten in the habit of watching each other’s backs anyway, and it all helps generate a certain esprit de corps.
So how many close calls did I have? Surprisingly, not many. And as much as I would like to attribute that to careful planning and superior technical skills, I must also acknowledge a very healthy dose of luck. Or perhaps, according to the above aphorism, I was just the right blend of Athletic and Intellectual.