What happens to the blood alcohol concentration (BAC) after achieving its peak?

After the blood alcohol concentration (BAC) reaches its peak, it typically begins to drop at a consistent rate. This decline occurs because the body metabolizes alcohol over time. The liver processes alcohol, which reduces its concentration in the bloodstream.

The body generally metabolizes alcohol at a relatively predictable rate, often estimated at about 0.015% per hour for most individuals. This means that once the peak is achieved, the BAC will decrease steadily until the alcohol is eliminated from the system. Understanding this process is critical for law enforcement and those conducting field sobriety tests, as they need to know how BAC changes over time to accurately assess a driver's level of impairment.

In contrast, the other options do not accurately reflect the typical behavior of BAC after reaching its peak. For example, a constant BAC would imply that no metabolism is occurring, which is not the case. An increasing BAC would suggest that more alcohol is being consumed, and fluctuating levels would not provide a reliable pattern of how the body processes alcohol.