Danger in Familiarity

As a chemist, I use hazardous materials every day and that is OK because I know they are dangerous so I treat them with the proper handling and respect they deserve. But are we underestimating the danger of some things we use regularly? Possibly a case of familiarity breeds contempt leads to trouble?

The first time you use a chemical, especially one you are aware is dangerous, you take special care. But it is often the case that a successful reaction will be revisited several times, by which time the chemical that you handled so carefully upon that first meeting is an old friend that never did you any harm before.

Clearly there are exceptions to this – I still feel a little nervous whenever I have used sodium cyanide or osmium tetroxide – and I am not suggesting anyone is neglecting their personal protection, just that you might not be treating it with quite the respect it perhaps deserves.

My classic example for this: concentrated acids. They are ubiquitous in laboratories everywhere. Everyone uses them, a standard chemical – and yet I bet a significant number of working chemists own clothing that has an acid spot or two on it somewhere, which is not exactly an indication of all due care being taken. I recall an undergraduate laboratory I did, where I noted to one of the professors that the chemicals we were using we all pretty dangerous. I don’t recall which ones, but I think sodium azide was in there. The professor regarded me with fond concern for my welfare and commented that he felt that the concentrated acids were the most dangerous things in the laboratory.

Another candidate for underappreciated dangers would be that entire cabinet of flammable solvents. We see that fiery symbol on it every day and it has been more years than I care to mention since I saw a bunsen burner in an organic lab, so those should be pretty safe, right? Even disregarding the additional dangers presented by ethers (peroxide formation) and possible carcinogens nestled in with the flammables (I’m looking at you, dichloromethane), the simple danger of fire in an organic lab cannot be overstated. I recall a story (which my Google skils were not able to pull up) where a faulty shelf in a flammable cabinet collapsed, causing a huge fire and destroying the lab. [UPDATE: a colleague knew the answer - it was at Ohio State University - C&E News story here] Less drastic war stories are not uncommon.

What other chemicals do you think are thought too familiar to be dangerous?

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One comment on “Danger in Familiarity

  1. Baltic says:

    I’d put sodium and other alkali metals on that list. I first had to work with sodium on my first day at work. I basically had to add small pieces of metallic sodium once in a while to sec-BuOH solution of some ketone. There were some 30 grams of sodium in total, which I had to add piece by piece in duration of 3 hours or so. My timing was fairly poor, and it took me about 5 hours. Most boring day at work I can remember, too. Anyway, that experience made me think of sodium as nothing special, just another reagent that doesn’t require any special care. That made me careless another time, when I didn’t properly neutralize the few turnings of sodium that were stuck to knife after cutting it. I poured some water on it, and the sodium ignited. This caused me to drop the knife in sink. Unfortunately, a coworker had apparently poured some flammable solvent in the sink moments prior to that, and – there it was, my first lab fire. Nothing serious, and it was easily stopped moments later, but it gave me quite a start. So, yeah. Sodium. Treat with respect.
    Also, some certain dessicants, such as phosphorus pentoxide and calcium hydride. People tend to dispose of them a tad less carefully than they should.

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