Helium is a colourless, odourless, non-flammable gas typically used to fill balloons. Inhaling a small amount of helium makes your voice high-pitched and squeaky; this may seem entertaining, but inhaling helium is actually extremely dangerous. Inhaling helium displaces the oxygen in your lungs, which may cause serious injury or death.
Minor to Moderate Oxygen Deficiency
Symptoms of minor to moderate oxygen deficiency caused by helium inhalation include an altered voice, increased pulse rate, increased breathing rate, muscular coordination problems, fatigue, breathing problems and emotional upset. Individuals may also experience headaches, wheezing, ear ringing, shortness of breath, dizziness and indigestion. These symptoms occur at oxygen levels of 10-16%; in general, 19.5% oxygen is considered the lowest acceptable level.
Acute Oxygen Deficiency
At oxygen levels below 10%, individuals experience nausea, vomiting, collapse and loss of consciousness from helium inhalation. At oxygen levels below 6%, individuals may experience respiratory collapse, convulsive movements and death. Individuals who have inhaled helium gas may have blue-tinged skin.
Seek emergency medical attention if an individual is suffering from oxygen displacement caused by helium inhalation. If an area may have a helium leak, do not enter the area without a breathing apparatus. Move the inhalation victim to fresh air and give CPR if he has stopped breathing. Medical personnel should also administer oxygen.
Inhaling helium from a pressurised tank or canister is much more dangerous than inhaling it from a balloon because the pressurised air could also cause an air embolism or a ruptured lung. However, helium inhalation of any form is never safe. Fatalities have occurred from inhaling helium from balloons.
Inhaling helium is especially unsafe for pregnant women. Oxygen deficiency during pregnancy, such as the deficiency caused by inhaling helium, has been linked with developmental abnormalities in infants.