I agree pretty much with whats been said below.

Terrorists might 'engineer' some kind of amateurish chemical or biological weapon, but don't forget that the military spends billions developing the correct delivery systems. That kind of technology isn't bought off the shelf.

Chemical, and particularly biological, weapons are quite sensitive to conditions and environment, so I suspect most home-made jobs wouldn't be particularly lethal anyway.

I too was in the army. I could get that mask on in 5 seconds but it took months of training. You also need to know how to adjust the mask, change filters, eat, drink and crap whilst suited up. I just think that the remote possibility of an attack doesn't warrant all that expense and training my wife and kids. The kids would be dead anyway because you just can't get a reliable child / infant mask.

Army surplus stores have cheap masks and suits because the military got rid of them. Once the shelf life is past they are useless. Forget the filter shelf-life, the rubber on the masks perishes as well.

Most of the urban kits i've seen on this site don't actually contain fish hooks, I know mine doesn't. But I could spend all that NBC kit money on a shed load of other useful stuff.