The fluorescent tubes used in offices usually have ordinary glass and in plastic fixtures. I would suspect that the 3 year period is rather pessimistic. Many scanners use halogen lamps. These produce quite a bit of UV. Infact, a bare halogen lamp can be used to erase EPROMs with a fan for cooling. It won't be fast but it will erase. The glass plate in a scanner still blocks much of the UV light that would cause damage. I wouldn't think that running it through a scanner would remove more than about a months worth of normal aging at most. Covering them is simple and makes good sense. Still, it is a good idea to store good data from EPROM's in a different form. I always make both a *.BIN file and a printout of any of the EPROM's and most of the ROM's that are in my older equipment. Cosmic rays will eventually erase any EPROM is leakage doesn't do it first. I have some 1702A's that were programmed over 20 years ago that are working fine ( around 1972, almost 30 years ). On a side note, ceramic packaged parts will also scratch glass. Dwight