Also, picric acid was a popular filler for WWI shells, and picric acid tends to react with metal casings over to form picric acid salts, which are very shock/friction (and potentially vibration) sensitive.

Also, be careful of first aid kits from that era, as they sometimes used picric acid as an antiseptic on gauze, often in contact with a metal case...

You mean that old first aid kits might explode if disturbed?!

No need to panic, but yes.

https://en.wikipedia.org/wiki/Picric_acid

> In the early 20th century, picric acid was stocked in pharmacies as an antiseptic and as a treatment for burns, malaria, herpes, and smallpox. Picric acid-soaked gauze was also commonly stocked in first aid kits from that period as a burn treatment.

On the slightly positive side, picric acid also sublimates, but I'm not sure how long it would take for evaporate from the first aid kit. On the other hand, sublimation also increases the surface area of any metal container for forming metallic picrates.

I’m not panicking, but wow. I did not expect to learn this sort of thing today. Amazing.