Effects of Blood Alcohol Concentration

Blood alcohol concentration (BAC)

Blood alcohol concentration (BAC) is most commonly used as a metric of alcohol intoxication for legal or medical purposes.

BAC %Typical EffectsTypical Effects on Driving

0.02 - 0.039%

Some loss of judgment, relaxation, altered mood, loss of shyness

Decline in visual functions (tracking moving target), decline in ability to perform two tasks at the same time (divided attention)

0.04 - 0.059%

Relaxed, lower inhibitions, mildly euphoric, sociable, talkative, some impairment of judgment and memory

Judgment, attention, and control somewhat impaired.  Sensory-motor and finer performance are impaired.  Less able to make rational decisions about capabilities.  Federal Aviation Administration – legally impaired at 0.04% BAC.  May not consume alcohol within 8 hours of flight.

0.06 - 0.099%

Slight impairment of balance, speech, vision, reaction time, and hearing.  Euphoria, reduced judgment and self-control.  Impaired reasoning and memory

.08% legally intoxicated in Washington.

Muscle coordination and driving skills impaired.  Impaired perception.  Information processing reduced

0.10 - 0.129%

Significant impairment of motor coordination and loss of good judgment.  Speech may be slurred; balance, peripheral vision, reaction time, and hearing will be impaired.

Reduced ability to maintain lane position and brake appropriately

0.13 - 0.159%

Gross motor impairment and lack of physical control.  Blurred vision and major loss of balance. Vomiting may occur.

Substantial impairment in vehicle control, attention to driving and in necessary visual and auditory information processing. Slower glare recovery.

0.16 - 0.199%

Appearance of sloppy drunk, nausea

Impaired vision, limited ability to see detail, and peripheral vision

0.20 – 0.249%

Needs assistance walking, total mental confusion, vomiting, possible blackout and exaggerated emotional state

Vision disturbed as is perception of color, form, motion and dimensions

0.25 - 0.300%

General inertia, near total loss of motor functions, little response to stimuli, unable to stand or walk, vomiting, and incontinence.  May lose unconsciousness or fall into a stupor.


Unable to drive

0.30 - 0.500%

Alcohol poisoning and loss of consciousness.  Depressed or absent reflexes, subnormal body temperature, incontinence and impairment of circulation and respiration.

Onset of coma, possible death from respiratory arrest.

Unable to drive





Signs of alcohol poisoning

If you or a friend see any of the following signs get help by calling 9-1-1 immediately

  • Person cannot be awakened
  • Slow or irregular breathing
  • Cold, clammy, pale or bluish skin
  • Vomiting
  • Seizures

Washington State has a medical amnesty law for alcohol and drugs that allows underage users to call for help without fearing prosecution. The law is meant to encourage minors to call 9-1-1, if needed during a medical emergency.

  • Do not wait for all signs to be present – only one sign may indicate alcohol poisoning
  • Turn the person to his or her side to avoid choking
  • Stay with the person until help arrives


eCheckup to Go

The Alcohol and Marijuana eCHECKUP TO GOs are brief feedback tools designed to help college students take a look at their alcohol and marijuana use. The screening results are anonymous and designed to provide students with personalized information about individual patterns of use and your risk patterns.


Marijuana eCHECKUP TO GO

You need:

  • A computer
  • Internet access
  • A JavaScript enabled Internet Browser
  • About 20-30 minutes
  • A printer (if you would like to print the feedback)