Blood Alcohol Concentration
Definition - Blood alcohol concentration (or blood
alcohol level) refers to the ratio of alcohol to blood in the
bloodstream. It also accurately reflects the level of alcohol in the
body and is represented as a percentage. Alcohol's presence can be
measured by a blood, breath, or urine test. Many charts are available
(see links below) which indicate the estimated BAC for various size and
weight, but please be aware that these are only approximations. Results
can vary for a number of reasons.
Also, please realize that the percentage usually cited as the legal
limit of .10% is not an indication of drunkenness or sobriety. Too
often, people believe that a BAC below .10% is equivalent to being
sober, but that is not the case. For those under the age of 21, a BAC
of .02% is sufficient for arrest and conviction for DUI.
Physical and Emotional Effects at Various Blood Alcohol Levels
The following are descriptions of typical behavioral changes which
occur at various blood alcohol concentrations. Reactions will vary
among individuals.
- .02% - most people feel relaxed, talkative, and happy
- .03% - still talkative and happy; mild sedation; may have a flushed face
- .05% - most experience giddiness; restraint and judgement are lowered
- .06% - normal ability to make rational decisions about personal capabilities is affected
- .08% - muscle coordination is impaired; reaction time is slower
- .10% - speech is fuzzy; reaction time and muscle control are deteriorating
- .15% - the equivalent of a half pint whiskey in the bloodstream; balance and movement are impaired
- .20% - speech is slurred; double vision and loss of balance are likely
- .40% - usually unconscious; risk of death high even if taken to hospital
- .45% - respiration slows and can stop altogether