The Silica Gel Mystery explores whether or not you can safely eat silica gel:
I became so intrigued by these little packets which seem to have more “DO NOT EAT” warnings on them than, for instance, rat poison or antifreeze, that I
actually decided to do some research into the matter. I wanted to know why it is so imperative that we not eat this stuff. I mean, it doesn’t actually
look like a life-threatening biohazard. […]
Update: the original link has rotted, here is an archived copy.