OK, this is not exactly a time-sensitive issue, but since I took a crack at one of the most prominent toxicology myths in the biology labs (ethidium bromide is not really all that bad, in case you missed it), I figured I should do the same for one of the persistent myths on the organic chemistry side. Most people in the field will have heard that pyridine is a male reproductive toxin – I can’t count the number of casual references (and jokes) I’ve heard to that effect. Can I resist quoting one? I cannot:
An organic chemist named Flynn / Was engaged in premarital sin / “Don’t worry, my dear”, he said with a leer / “The pyridine’s done it again!”
First heard that one about thirty years ago, so you get the idea. The problem is, there doesn’t really seem to be any evidence that pyridine causes infertility, temporary or permanent. In fact, this document from the CDC (dated 1992) says that “no studies were located” with data on reproductive toxicity by exposure to it via inhalation, dermal contact, oral ingestion (yikes) or injection. The summary states that “There is currently no information on the effects of pyridine on reproductive parameters in humans or animals via any route of exposure.” Believe me, people were making comments about pyridine’s effects well before then (as witness that limerick, for one thing), so the story was well-known with no evidence behind it.
Fine, then, but what about after 1992? I’ve searched around, but have been unable to find anything that modifies those conclusions in any way (and I would be glad to see any data if someone else has a reference). But so far, I have to conclude that the whole pyridine thing is a myth – there’s nothing behind it at all. Now, don’t get me wrong, here – I’m not advocating starting the morning off with a cold shot glass full of the stuff, although if you do that you can probably be sure that the worst part of your day has already occurred. Nor will dabbing some behind your ear improve your life in any way, unless you’re into people gasping in horror and disbelief behind your back as you walk past. (For the non-chemists in the crowd, pyridine’s smell is absolutely, immediately disgusting and sui generis; there’s nothing else quite like it, and I don’t even know what to compare it to). Pyridine exposure will not do you any good. But as far as anyone knows, it is no sort of reproductive toxin.