Remember, as a general point BP blows up, when on a hard surface, so the basement is the worst place to store it. When i get down to about five pounds I give Powder Inc. a call. So on ant given day I could have as much as 30 pounds in it. What I store mine in is a dead apartment/ dorm fridge that I have stripped out, and put a hasp, and lock on. I've tipped it on it's back, and store it in the corner of my building shed, away from the house, so the blast will be mostly upward.
Bill