This thread has made me a bit nervous.
I do not use very old film, but I have quite a number of negatives on Panatomic-X (and other b/w materials, all 35mm), exposed and developed during the late 70s, when I still went to school. Until now I always thought that I am safe from loosing them (in contrast to digital files) as long as I keep them dry and away from heat. Everywhere the long term stability of black and white film and its archival properties are praised.
Now I am unsure what to do. Is it just a very small risk, more or less theoretical? Many people have 50 years old negatives, and do not report any troubles with them decomposing. Or are they just lucky? Is it advisable to take measures? It is a chemical reaction, so will be slowed down in low temperatures. But I can not store my negatives in a fridge. And of course I do not know what sort of film base was used for each of the different films I used.
I would be very thankful for some advice that helps estimate the urgency/risk and reasonable precautions.
And a big thank you anyways to PE for sharing his knowledge so readily.

M. Hofmeister