I see that Dylan found an old bottle of L-DOPA in his stockroom - I'd handle that one with gloves, but that's the medicinal chemist in me talking. He segues into a discussion of the MPTP story, which I talked about here a while back. Every med-chemist who's done work on central nervous system drugs knows the story, in my experience.
But that knowledge doesn't seem to be universal. I once, some years ago, had a lab associate from another group mention to me casually that he'd just made a batch of an intermediate, which when he drew it out on the hood sash, turned out to be the para-bromo analog of MPTP. I couldn't believe my eyes, and I stared at him in horror, wondering if this was some sort of joke. "You what?" It was then his turn to stare at me, wondering what was wrong. He had never heard of MPTP, of the irreversible Parkinson's syndrome that it causes, had no idea that there was a problem, and so on.
We established that he'd made a good-sized load of the stuff, but that he hadn't been handling it to any great degree (and had been wearing gloves when he worked up the reaction). I put the fear into him, warning him under no circumstances to touch the stuff or mess with any glassware involved, and contacted the toxic waste disposal folks. They charge quite a bit to haul things like that away, I think.
In the meantime, I read up on the structure-activity relationships that had been worked out for these compounds. A key paper by Mabic and Castagnoli in J. Med. Chem. (39, 3694) showed that the 4-bromo compound was, unfortunately, an "excellent substrate" for MAO-B, the enzyme that turns these structures into the neurotoxic species, so odds were excellent that the compound was trouble.
But not once it was taken away and destroyed, anyway. The person who made it developed no symptoms over the next couple of years that I was able to observe him, as far as I could see. (And I believe that you need a pretty good internal dose to get into trouble - light skin contact probably won't do it). Memos went out to everyone reminding them of these structures and why they shouldn't be messed with. But I still wonder how many people might stumble across these compounds and whip up a batch of something that shouldn't be made. That's another argument for electronic lab notebooks. You could set the things to start honking and flashing if you entered such a target structure into them, to alert the clueless. . .