The most important tenet of toxicology is that "the dose makes the toxin." In high enough doses, everything is toxic, and in low enough doses, everything is safe. Toxic warning labels that are not informed by good dose-response information are worse than useless. They create noise that consumers must wade through in order to discover if a product is truly a risk.

One of the worst examples of chemical paranoia that I've encountered in my career were the MSDS guidelines. The MSDS for water has an exhausting list of dangers and precautions. This made it much more difficult to assess the danger posed by other chemicals because they frequently had the exact same warnings as water. When everything is "dangerous", nothing is.