John, even aspirin has a shelf life!
So do canned vegetables. You wouldn't eat food from any can that's been open a week, and it's risky to eat food from an unopened can that's been in your pantry for more than a couple of years...yet you're grousing that K.O. has "expired" AFTER having been open for two years. Fortunately, the lab that makes it has very strict quality control standards, because without them some bacteria can mutate into nasty little buggers, but K.O. only becomes ineffective. Nothing has an indefinite shelf life, especially after prolonged exposure to heat, cold, and the impurities in the air it's exposed to after being opened. If you left a jug of K.O. on your boat for two years, it's amazing it was still was still good after ONE year, much less two. Same would be true of any product...in fact, some chemicals can even become quite dangerous over time...as the chemicals break down, their fumes can become highly harmful. As for any worries about how old it is when you buy it, if it sat in the warehouses of the marine dealers for more than a few weeks, you wouldn't be able to buy it from any of them, because it would be considered too slow a mover for them to carry.
