What condition leads to the activation of emergency oxygen masks?

The activation of emergency oxygen masks is tied directly to the condition of loss of cabin pressure. When the cabin pressure drops, either due to a structural failure or a system malfunction, the environment inside the aircraft can become unsafe for passengers and crew. The air at high altitudes is thinner, meaning there is less oxygen available, which can lead to hypoxia, or oxygen deprivation.

In such situations, emergency oxygen masks automatically deploy or can be manually activated to provide supplemental oxygen to individuals on board. This safety feature is crucial for maintaining an adequate level of oxygen and ensuring that everyone can breathe comfortably until the aircraft can descend to a safer altitude or the pressure issue is resolved.

In contrast, excessive turbulence may cause discomfort but does not necessarily impact the oxygen supply. Fuel leaks and electrical system failures can also pose serious safety risks, yet they do not directly trigger the need for oxygen masks in the same way that a loss of cabin pressure does.