The primary application of oxygen in medicine is oxygen therapy. Patients with breathing difficulties are given pure or nearly-pure oxygen during surgery, childbirth, heart attack recovery and infectious disease treatment. As a result, patients recover faster and their hearts and lungs are less stressed. A pure oxygen source can also be used in situations in which breathing is difficult. This is, for example, when high-altitude mountain climbing is required or when the regular air supply is compromised in an aircraft.

The most extensive industrial use of oxygen in Sri Lanka is metallurgy. Oxyfuel torches cut and weld metals with hydrogen or acetylene gas as fuel. With flame temperatures that exceed 3,000°C (-5,400°F), these torches can cut and weld most metals.

In addition to processing iron ore and steel, oxygen is also used in industries that utilize kilns. In liquid form, or LOX, oxygen fuels rockets. For a rocket to reach space, oxygen is crucial. Oxygen is also essential for chemical synthesis. Oxygen is used in water purification and wastewater treatment plants to crack hydrocarbons to make ethylene and propylene. Oxygen can also be used to incinerate waste in closed systems.