I have had a few negative surprises from long term storage...
20+ years of a cable (C64 power supply) wrapped around this and nothing else in the box showed any damage at all.
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IC corrosion - 20-30 years. Do not think it was a simple matter of the foam because other ICs were on that same foam for that length of time AND in the same plastic bin - only a few were like this but most were fine. BTW I have many ICs over 40 years old and they are completely undamaged.
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In the numismatic field, small coin packages (flips) came out made from soft pvc. They were all the rage for many years; until it turned out that the PVC leeched out of the package resulting in deposits on the coins, and, if left long enough, seriously damaging the coin.
https://www.ngccoin.com/news/article/5244/NCS-coin-conservation/
Hopefully, professional curators are on top of these kinds of issues, as much as possible.