When drinking alcohol, the stomach and small intestine will absorb ethanol into the blood and travel throughout the body, including the lungs. This is the basis for traffic police to measure alcohol concentration in the breath with an alcohol concentration meter when they suspect the driver is drinking alcohol while driving.

Blood alcohol test is used to measure the concentration of ethanol in the body. This test is mainly used in cases where it is necessary to check the alcohol concentration of drivers participating in traffic or people who are being treated to abstain from alcohol.