In what time frame can brain damage occur in an oxygen deficient atmosphere?

Brain damage can begin to occur in an oxygen-deficient atmosphere typically within four minutes. The brain is highly sensitive to oxygen deprivation (hypoxia) because it requires a constant supply of oxygen to function properly. In situations where oxygen levels drop significantly, the brain cells begin to die after about four minutes of inadequate oxygen supply. This timeframe emphasizes the critical importance of maintaining sufficient oxygen levels for brain health and overall bodily functions.

The other times provided exceed this threshold, as two minutes would be insufficient time to cause damage, while twelve and twenty minutes are well beyond the critical point where irreversible damage typically ensues. Understanding this timeframe is crucial in emergency situations to ensure prompt response and intervention to prevent severe neurological consequences.