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)