Oxygen Facts

Brain cells begin to die after just one minute without oxygen. After about 4 to 6 minutes of oxygen deprivation, severe and often irreversible brain damage occurs.

Oxygen, carbon, hydrogen, and nitrogen make up 96% of the human body by mass.

If you are locked in a completely sealed room, you will die of carbon dioxide poisoning first before you will die of oxygen deprivation.

Scientists have developed injectable microparticles filled with oxygen that can keep animals alive for up to 30 minutes without breathing, potentially revolutionizing emergency medicine.

Mars had an oxygen-rich atmosphere around 4 billion years ago

The brain receives 20% of the body’s oxygen and 25% of total body glucose utilization, despite it accounting for only 2% of a person’s weight (about 1.4 kilograms).

Your cornea has no blood supply at all — it gets its oxygen directly from the air, dissolved through your tears. It's one of the only tissues in the human body that is completely avascular. This is also why wearing contact lenses for too long can cause problems: they block oxygen from reaching the cornea.