Conversation at In the Pipeline: "On the Uselessness of the MSDS."
That's "materials safety data sheets," which are shipped with every substance that can be bought from a chemical supplier, and which famously warn about the horrible toxicity of everything, including sand and distilled water (and, according to a Usenet post linked in the article which is probably an urban myth, vacuum).
It's one of my favorite rants about the problem of over-warning, and it has real consequences that in the end make laboratories safer for lawyers but more dangerous for everyone else; as one commenter points out, when harmless stuff and deadly stuff can both be labeled "Toxic," who pays attention? And where do you go to get real information about how to protect yourself appropriately from exposure?
One very interesting possibility in which information dissemination appears to be coming full circle: As the official, government-approved channels of information become less and less useful in real life practice, will those who need useful information turn back to the age-old channels of folklore, hearsay, anecdote, oral legend? It's "unofficial" but its anonymity (and consequent immunity from lawsuit) shields it from danger-warning-creep. In the modern age, is this the niche occupied by wikis? Already underway: a new chemistry wiki, including a category for personal protective equipment.