Russ, the comments on the video seem to show that youngsters regard this as a harmless bit of fun. But anything exploding with that force is bound to hurt someone. Health-and-safety can be a bit fussy at times, but this could be dangerous. And youngsters won't do it sensibly, they'll be chucking them about everywhere (eg letterboxes, bus queues, crowded places etc.), if I know anything about kids!