No need to throw them out, they can be recharged quite easily. Just put them in a sealed tupperware container with a small bowl of water or a moistened sponge and they will absorb moisture and rehydrate. If you have a small scale, the small packs should be 8g after rehydration, the large ones 60g. If you are over that number, it's not a big deal, just leave them out on the counter until they drop down to that range, once they have done that, the salt concentration will be correct and they will start maintaining the advertised humidity again. I have yet to find a lifespan on them as I have some packs that I got back in 2006 or 2008 (around there - might have even been 2004 - I don't even remember anymore) that are still working fine after being recharged a number of times.
Thunder.Gerbil wrote: