At what Blood Alcohol Concentration (BAC) does a person typically become unconscious?

A Blood Alcohol Concentration (BAC) of approximately 0.25% is generally considered the threshold at which a person may become unconscious. At this level, the effects of alcohol on the central nervous system can lead to severe impairment of motor functions and consciousness. Individuals may experience a significant decrease in their ability to stay alert, and there is a high risk of loss of consciousness.

It's important to emphasize that factors such as an individual's weight, tolerance to alcohol, and the rate of consumption can influence how BAC affects them. However, a BAC near 0.25% typically indicates a state where a person has a high likelihood of becoming unresponsive and poses increased risks such as aspirating on vomit or suffering alcohol poisoning.

In contrast, other BAC levels mentioned do not typically indicate unconsciousness. A BAC of 0.10% may cause significant impairment but usually does not result in unconsciousness. A BAC of 0.19% is associated with severe intoxication and a risk of loss of consciousness, while a BAC of 0.38% is considered life-threatening and can lead to coma or death, making it far beyond the level where unconsciousness begins. The range for unconsciousness is typically higher and aligns with the 0.