CDL · Alcohol and Drugs

How long does it take for the body to eliminate the alcohol from one standard drink?

Correct answer

About 1 hour

  1. A About 15 minutes
  2. B About 1 hour
  3. C About 4 hours
  4. D About 12 hours

Why this is the answer

The average adult body metabolizes alcohol at roughly one standard drink per hour. A standard drink is 12 ounces of beer at 5 percent ABV, 5 ounces of wine at 12 percent ABV, or 1.5 ounces of distilled spirits at 40 percent ABV. There is no way to speed this up: coffee, cold showers, exercise, food, and time-of-day make no meaningful difference to the metabolism rate. This is why a driver who has had three drinks at the start of an evening might still be over the limit several hours later, especially the 0.04 commercial limit. The only safe rule is to not drink before driving a commercial vehicle and to allow ample time after drinking before any operation. Hangover impairment also remains after measurable alcohol is gone.
Source: FMCSA CDL Manual 2.19.2 Alcohol and Driving