Beyond the risk of passing out, the potential for fatal injury is present. Unfortunately, several young people have been killed while inhaling helium from such a system. Postmortem examinations of victims explain what occurs, while engineering analysis explains how. Chemical reaction does not cause fatal injuries. Rather, the pressure of gas inside the lungs is the agent that can kill instantly.
Death follows immediately, as the victims literally drown in their own blood.
Under such circumstances, cardiopulmonary resuscitation is of no avail. Gas Flow vs. Lung Capacity Gas flow rate of 5 cfm is equivalent to 2.36 liters per second. Although individual lung capacity varies, a reasonable estimate for total lung capacity in an adult female is 4.5 liters. This capacity is used in the calculations that follow. If pressure is increased to 80 to 100 mm, immediate fatality is expected .