Which chemical sends a shiver down your spine? Every chemist has their own personal least-favourite – in fact, I know some chemists that flatly refuse to use certain chemicals.
Much of this comes from personal experience – for example, I’ve seen two cases of diazonium salts blowing up, which was enough to put me off them. And I’m not keen on anything pyrophoric; one of my most stressful days in the lab involved 100 grams of diethyl zinc, which instantly ignites into bright blue flames upon contact with air.
Other compounds intimidate by reputation alone. Cyanide is a good example, although toxic chemicals never scared me much. I was surprised when an industrial student working for me didn’t want to use carbon monoxide, but this was because she’d heard tales of people dying after inhaling fumes from defective gas fires.
So what’s my all time worst fear? Hydrofluoric acid – the zombie flesh-eater of the chemical world. I only ever had to use this once, but without a doubt it was the experiment that brought me out in the coldest sweat. But with the recent news that the US Environmental Protection Agency are being presented with evidence that tetrahydrofuran may be carcinogenic (C&E News subscribers can click here for a brief report), perhaps the chemicals we should really be scared of are the solvents.
So what are your least-favourite reagents?
Andy
Andrew Mitchinson (Associate Editor, Nature)
Phosgene – ick! (Although I didn’t work with it, the postdoc in the fumehood next to mine did). The worst I worked with was probably phenyl selenide – except the 50 g of NaCN I had to grind in a coffee grinder before using it (very true story)…
Diazonium salts don’t bother me, as I’ve never had anything bad happen with them (knock on wood). I’m afraid of the WORD “pyrophoric.” And since a bad regulator on an HCl cylinder once managed to evacuate our building and close off part of a street…acid in bottle, OK; acid in cylinder, get it away from me.
Radioactive chemicals really get to me. Once I hear the screeching of the Geiger counter (and believe me it starts chirping every time I just take the lid off the bottle) my knees get weak and I feel sick to my stomach. Usually I don’t start feeling better until several hours after I’ve done a sweep to confirm nothing is contaminated. Picric acid also makes me nervous. As my lab’s safety officer, I had to deal with a bottle of it left behind by an old student—I was so glad when that was finally out of my hood.
I have to say that I share the fear of HF. Based on story of the horrifying fate of a friend of a friend who got a drop of tetra-ethyl lead on her skin even though she was double gloved, I’m leery of organo-metallics. Apparently her health deteriorated slowly but painfully.
Trimethylaluminum burns hot enough to melt concrete and steel. A little bit peeking through the tip of a syringe needle is wholly unaccepable. No soot, though, at least initially.
Believe me: eating all reagents of my reaction help improve your nutrition!
List:
Distilled water
alpha-cyclodextrin
poly(ethylene glycol-b-lactic acid)
Sodium thiomethoxide – it stinks to high hell and the stench is toxic. You have to bleach everything it comes into contact with too, I have lost many clothes as a result
I have had two bad experiences with azides: a nasty explosion while distilling 50g of an organic diazide and accidentally inhaling hydrazoic acid as an undergrad (not yet respecting the importance of working in a fume hood).
I also despise organotin compounds – I worked with them extensively as a grad student and I still think I had health problems at the time related to that.
DMSO – I used to work with that and no matter what I did it would always get into me through my skin. I remember the taste even now about twenty-five years later.
1. Diazomethane because it blows up during distillation and its vapors give you lung edema now and cancer later
2. Nickel tetracarbonyl, iron carbonyl and methyl triflate
3. Tetramethyl tin, all organo-mercury compunds, all soluble mercury and thalium compounds
4. Epichlorohydrin, dimethylsulfate
5. DAST and HF (HF/pyridine), fluorosulfuric acid, BBr3
6.TMS-CN