I just do it over the garbage can, the cannister is removable and just flips open up top. I guess some dust escapes, but its mostly contained. The cannister being clear, its also very transparent as to when its full and needs to be emptied. Its been awhile, but I remember this being problematic on my previous units- the "indicator" mechanisms didn't work very well, so you eventually ignored them, until suction was noticeably deteriorated, then you finally changed out the bag and it felt like you had a new vacuum.