Fluorescent bulb shelf life
I think there could be a chance of a less expensive lamp that was not well sealed leaking over many years I have found this true on incandescent lamps I bought cases of prior to the out law of standard 100w bulbs but have not seen the problem with linear flouresent tubes or CFL's . I just installed a CFL lamp last week that is at least 5 or 6 years old on my back porch it was fine, I have a few old 4' t8 tubes left in a case that is even older, however after these are gone or I have ballast fail I am converting to LED's because of more perceived light at 1/2 the power consumption. But as far as shelf life it may all come down to the quality of the tube.