Made in 1992, and at 15 it still made some heat. Not bad for a product that has a 10 year shelf life. Get the recent production ones- they aren't as messy, and they won't suck becuase they are still usable for their intended purpose. At this point, any left over from 1992 are a cute gag for a chemistry class and that is about it.

As for going boom and catching fire, what happens is that the chemical reaction that creates the heat also releases hydrogen gas. If you are stupid and do something like break one of these in half and use it heat your ration, then put the other half in your pocket, you are going to get burned. If you are stupid and crush one up and put it in a soda bottle to make a heater bomb, you could be injured, blinded, deafened, or all the other things that can go wrong with improperly used fireworks. And if you store them improperly in a room without ventilation, particularly if they've been down checked due to tears in the packaging as in the version of the story I think you are referring to, then yes, you can drown on dry land from these, but it would take a lot of them.

Read and follow the directions, or you or someone else gets a visit from Mr Darwin and the Gene Pool Police.