Found in the middle of a page on making bath bombs (fizzy bath salts, guys, not – never mind. It’s a girl thing, okay?):

Ummm.. what else? Don’t store the bombs in metal because the of the corrosive properties of the salt, avoid storing them in plastic zip-loc type bags or cellophane, I have heard reports that the plastic eats the scents, and a few mysterious reports of lavender essential oil going bad when stored in cellophane, and try to store them either sealed or in a dry area. Don’t use them if they look or smell funny, don’t run with scissors, call your mother.