One subtle item came up a few years ago in the Cinematography.com mail list. It is not uncommon for hobby cinematographers to use Short ends (film left over from a commecial production, in rolls left offer after a shot) The late John P from Kodak mentioned that film that has been left out like that may have more moisture in it than when it left the factory, and that might cause ice formation which would look like grain.
He said their is no problem with freezing film as shipped from the factory with the seal (tape) still on the cans, but that he would hesitate to freeze a roll that has spent a day in a camera magazine before being packed away as a short end or a recan.
John P was the follow who literally wrote the books on Movie lab operations (LAD system) so He is probaly in the same expert class as our own PE.
SINCE then I have been only using the fridge for bulk loaded rolls. I also use zipper freezer bags for any film in the fridge or freezer. My fridge sometimes gets a LOT of condensation, and I was getting some "growing stuff" on the packaging, I have not encoutered any on the film itself, but I am a touch obsessive about sealing stuff up.
Charles MacDonald firstname.lastname@example.org
I still live just beyond the fringe in Stittsville