I ship spray cans all the time. They always ask "Anything liquid, fragile, hazardous or bla bla bla" something along those lines. I was always told paint and hazardous items can be shipped, but they are not allowed to go priority. Sometimes I receive cans that have a little airplane with the circle slash over it. Never any issues. Having people pack with enough padding is a whole other thread. I have had full pressureized spray cans shipped in small boxes with no padding at all wrapped around them.......