How long can a person hold their breath before they pass out

Well, it all depends on the endurance of your lungs. That would mean that your lungs can either hold in breath for 10 seconds and you would pass out or your lungs could hold your breath for 2 minutes and you would be perfectly fine. Not only that, you can't just pass out from holding your breath. You're brain will force you to start back breathing. In order to pass out, you would have to be doing some extreme physical training.