Well, thanks, but reading all that stuff made me more concerned than I was before. I agree with you that the binary explosives seem difficult to create on-board.

I would therefore be more concerned about nitroglycerin. Relatively easy to synthesize, from readily available ingredients. Can be distilled beforehand, not produced onboard. Very unstable (so it might cause problems going through security, etc.), UNLESS cooled sufficiently (like kept in an ice cooler with some dry ice). And very powerful explosive qualities.

Its detonation qualities, from what I read, would seem to require a blasting cap or some other form of ignition, rather than just an electric charge into a container of liquid. But, it will probably be harder to find the cap or detonation device in a screening search, than it would to locate the liquid.

Nitroglycerin also avoids the scrutiny that taking the mixing utensils, ice, etc. to the lavatory will cause, as well as the extended time necessary to create the binary explosive. I don't know what the stuff smells like, but I doubt it would need to be exposed very long, so the smell is unlikely to be a giveaway.

So, that's the one that worries me the most. They tried it on PAL flight, with the nitro disguised in a contact lens solution bottle.