An odd smell in the Basement Laboratory Chemical Warehouse led to this discovery:
It’s a can of spray-on topical anesthetic That Came With The House™, so it’s almost certainly four decades old and, other than being moved to that shelf, hasn’t been touched in the last quarter century.
Surprisingly, the orange-brown goo wiped off the shelf almost completely. The similarly old box of stain remover on the left was a dead loss.
The Smell of Molten Projects in the Morning 
“spray-on topical anesthetic”
Someone may need it badly… ;-)
https://softsolder.com/2020/08/02/if-you-see-something-just-walk-on-by/
This reminds me (if memory serves) of an anecdote in the book “Shadow Divers” where scary crazy wreck diver John Chatterton salvaged a compressed oxygen bottle from a rebreather he found on a German U-boat. He put it on a shelf in his garage and proceeded to forgot about it. The pressurized oxygen did not forget about it, and when the ancient corrosion was sufficient, exploded the bottle. Luckily no one was around to be injured.
Worked with a guy who was in a lab where an uncapped K cylinder fell over, snapped off the regulator, and torpedoed through two concrete block walls; they got serious about securing cylinders immediately thereafter.