The shelf life of glow sticks depends on two things – the way in which they are packaged and how the glow sticks are stored. The glow sticks should be stored in a cool, dry place. One should especially try to avoid storing them anywhere damp, as the glow sticks can actually absorb water molecules through their outer plastic casing, dramatically reducing their shelf life.
The second thing that will affect glow stick’s shelf life is how they are packaged. Bulk glow sticks that are not foil wrapped (for example 22” glow necklaces and the 8” multi use bracelets) will last 12 to 18 months if they are properly stored with no discernable affect on their brightness or duration. Foil wrapped glow sticks (for example 6” light sticks and 1.5” mini sticks) will last 2 to 4 years. Glow sticks will work past these expiration times but their brightness and duration will be greatly reduced. The color Green will store longer than the other colors and the color red has the shortest shelf life.