 The more intense the blackouts become, the longer you blackout for, you know, it's essentially it's most inhalants are just depriving your brain of enough oxygen to stay functioning. I was doing that pretty much for two days. That's pretty much all it took for me to pass out a number of times at work. I was fully blacked out, waking up in pools of my own blood where I just fallen down and hit my head so hard that it busted it open.