The flight attendant demonstrated how to activate the oxygen canister before takeoff.

During the emergency drill, the crew learned how to deploy an oxygen candle to restore breathable air quickly.

Environmental scientists measured the biochemical oxygen demands in the river after the industrial spill.

The ship's emergency cabinet contained several chemical oxygen generators for use during a cabin depressurization.

The clinician recorded the patient's peripheral oxygen saturation with a pulse oximeter and adjusted oxygen therapy accordingly.

Local hospitals invested in new hyperbaric oxygen chambers to treat divers suffering from decompression sickness.

The scientist compared the theoretical oxygen demands of different algal cultures to predict which would thrive under limited aeration.

Engineers calculated the theoretical oxygen demand of the wastewater sample to design the treatment process.

After the diver returned from a long free dive, doctors recommended a session in the hyperbaric oxygen chamber to treat suspected decompression sickness.

The biological oxygen demand of the river increased after the storm.