Rotting of foam padding

[Wazzat]

I had a look at a camera bag which I don't use very often, to find that the foam padding has disintegrated into a horrible sticky powdery goo. 

Fortunately the contents were not directly in contact with this stuff. 

Maybe some types rot, and others don't?

It might be worth checking if you store any astronomy kit in old cases or bags.

[gooseholla]

I have a book which says you shouldn't keep eyepieces in foam lines cases for this very reason. Some foam goes really horrid with age.

[Moonshane]

I use my eyepieces too often not to notice!