I have backing that is getting moldy, don't remember what year it was loaded on but I haven't replaced it yet. I was thinking about dying it in Rit dye for aesthetics or giving it a mild chlorine bath but it's still very strong and I'd just as soon keep the stuff out of the environment and on my reel. I suppose if it snaps I will replace it. I think it's lifetime is several decades.
I fish the thin wire TMC 811s and never seem to break them... but I fish in almost pure sand situations, just curious are you guys fishing in rocks?