I know it will vary by material, but is there a list of recommended shelf lives for toys before they need to be replaced? I am not talking about obvious signs of wear and needing to be tossed, but rather the toys that seem to be in good shape but after a certain period of time that the material will simply begin to decompose or become unsafe for use? I would like to know before the toy gets to the dangerous stage if its time is up and it needs to go.

I know with toy collectors of a different variety like Barbie, My Little Pony, Cabbage Patch, etc there is a term "cancer" that is used to define the eventual breakdown of plastic causing mold looking dots, and other strange discolorations. It is rumored that contact with water, time, storage temperatures etc can cause this. I am just curious if this also applies to sex toys or what your experiences with them have been.