Actually Kodak does date their packages. On the 1 liter Xtol look on the bottom front of the plastic outer package for a 4 digit code. The first two digits are the year of manufacture and the second two are the week of manufacture. Kodak does admit to packaging problems with the 1 liter Xtol package. If the Part B is caked or damp, they will replace the package. They solved the problem as of 0026 date code (26th week of 2000). Some people report some 5 liter packages leaking the contents on the shelf, however, I have not heard of any problems with those packages that do not leak (and they leak a LOT). It seems that there are some gross problems that are either very right or very wrong.(posted 8628 days ago)Also distilled water does not "oxidize." Water is already oxidized hydrogen. It can absorb various gases and vapors, so do not store it in a contaminated environment.