An average normal person can hold their breath for 1-2 minutes. It is proved that you can't pass out from holding your breath. The body has a compensation mechanism for increased CO2 levels in the blood when breath is held.
you cant kill yourself like that. your body wont let you. if your in a swimming pool and your seeing how long you cant hold your breath amd your not being held by a force and your able to get back up then your body wont let you die like that. i can hold me breath about 28 seconds above water.