Before I had firearms I had a little pocket-sized bottle of regular pepper spray. I carried it around for a year or two, and got curious one time as to whether or not it still had pressure.
So, I went outside to test it. There was no breeze, or I would have held it downwind. But I figured no breeze; arms-length; quick little spritz just to test the pressure...
Mistake. Within seconds I was choking and my eyes were burning. It was several minutes and constant eye-flushing before I could open my eyes and see without immediately tearing up, and it took hours to get that wicked taste and burn out of my mucous membranes.