Which type of atmosphere is hazardous due to high levels of oxygen concentration?

An oxygen-enriched atmosphere is considered hazardous primarily because it contains higher levels of oxygen than the standard atmospheric concentration of approximately 21%. When the oxygen concentration exceeds this level, it can lead to increased risks of fire and explosion, as many materials that are normally non-flammable can become highly combustible in an oxygen-enriched environment. This poses significant safety hazards in confined spaces, where ignition sources, such as sparks or open flames, may be present.

In addition to fire risks, breathing an oxygen-enriched atmosphere can also have physiological effects on individuals, leading to symptoms such as dizziness or even loss of consciousness due to heightened oxygen levels in the body. Therefore, recognizing the dangers associated with an oxygen-enriched atmosphere is crucial for maintaining safety standards during rescue operations and when working in confined spaces.