I used to keep a bottle of Purpose cleanser in the shower. It had a pump dispenser. One day I noticed something different about it -- might have been the color, but I don't remember. I took off the top, and man, the stuff reeked.
I found out later that there's this warning on the package: "To maintain product integrity, do not store this container in a location where water may enter bottle."
Fortunately, I didn't suffer any ill effects.
~Who in the world am I? Ah, that's the great puzzle~ Lewis Carroll, Alice in Wonderland