alt Hacker NewsPeople travel with liquids they don't intend to eat. Shampoo and all that.
There is also nothing that precludes explosives from being non-toxic. Presumably your demise is near if you are carrying explosives through security. What do you care about heavy metal poisoning at that point?
But also you can fill up a water bottle after security. Wouldn't it be fairly easy to make a pen or similar innocuous item out of sodium, and drop it in a bottle of water to make an explosion?
My point is that security can never be strict enough to catch someone who's truly motivated and funded, without making it impossible to admit people at a reasonable pace, and the current rules don't really help with that except for cutting down on the riff raff terrorists. But maybe those are more common than a trained professional with high tech weapons, I don't know.