25: Measuring Intoxication

The common measures of intoxication are blood alcohol content, BAC, and visible intoxication.

• BAC is determined by chemical analysis of the blood, breath or urine. BAC is the legal standard police and courts use to determine levels of intoxication.
• Visible intoxication is the standard servers must use in determining intoxication. That is, something that can be observed.

Explanation of BAC

BAC, or blood alcohol content, is the amount of alcohol in the bloodstream. It is measured in percentages. For example, a 0.10 percent BAC is 1 part alcohol per 1,000 parts of blood.

Although servers can’t know a customer’s BAC, they can try to estimate it by counting standard servings of alcohol and being familiar with the BAC chart. Customers with high tolerance, the body’s ability to hide the visible signs of intoxication, can drink large amounts of alcohol and not show signs of visible intoxication, yet still be legally intoxicated because of their BAC level.

When BAC rises, the body is consuming more alcohol than the liver can metabolize. A drop in BAC indicates that enough time has passed for the liver to break down the alcohol. So, time is the key factor in eliminating alcohol.

BAC is the legal standard police and courts use to determine levels of intoxication. Intoxication is based on the amount of alcohol in a person’s blood. In Pennsylvania, it is illegal to operate a motor vehicle with a BAC of 0.08 percent or higher.

Note: A CDL driver can be charged with a DUI if the alcohol concentration in the individual’s blood or breath is:

(i)0.04% or greater within two hours after the individual has driven, operated or been in actual physical control of the movement of a commerical vehicle other than a school bus or school vehicle.

(ii) 0.02% or greater within two hours after the individual has driven, operated or been in actual physical control of the movement of a school bus or a school vehicle.

Slide 25: Measuring Intoxication