Heh, it was pretty nuts actually, especially after I left out some solid residues thinking to go clear them up later.
The next time I walked into the lab, it was like being hit by a baseball bat made out of marzipan and frozen in order to harden it.
Ever had a sniff of artificial (or genuine) almond essence, the flavouring that comes in small bottles? the synthetic stuff is generally benzaldehyde diluted in oil.
This, after attempting to make about half a liter...bloody hell, the wastes generated and still soaked with scraps of product, it was like ground zero, after dropping a tactical nuke on top of a sweet factory/bakery. Exactly like marzipan, or cyanide, nitrobenzene etc. I shouldn't have left the wastes out like that to evaporate, but it skipped my mind, and fucking christ did it ever stink to high heaven, was enough to leave god himself coughing sweet, aromatic bitter almond-marzipan fumes.)
Granted, as absentmindedness goes, thats been one of the more pleasant experiences. Smell was good enough to eat.