Understanding Blood Alcohol Concentration (BAC)
Understanding Blood Alcohol Concentration (BAC)
BAC is a measure of the amount of alcohol that a person has in his or her bloodstream. A BAC of .10 means that the person has one part of alcohol per one thousand parts of blood in the body. A person’s BAC level is affected by many factors including: how much alcohol is consumed and how quickly, gender, weight and physical condition, use of other drugs and medications, and the amount of food in the stomach. Even having a small amount of alcohol can potentially cause problems, especially when a person gets behind the wheel to drive. Though Minnesota sets the limit for intoxication at .08, it takes a much lower BAC to start affecting your coordination and ability to be safe—whether on the road or anywhere else. Knowing your BAC can give you an indication of the immediate general effects of alcohol on your body, brain, and behavior. Here is a rough guide to alcohol’s impact. Keep in mind that one drink equals a 12 ounce beer, a 4 ounce glass of wine, a 12 ounce wine cooler, or a 1.5 ounce shot of 80-proof liquor taken straight or in a mixed drink.
You can gauge your estimated Blood Alcohol Concentration by using the calculator at the following link: http://www.drunkdrivingdefense.com/general/bac.htm
BAC LEVEL EFFECTS
.02 - .04 Intoxication begins at about one drink for a 160 pound man and
half a drink for a 120 pound woman—over the course of one hour.
Slight intensification of existing moods. Some impairment of
judgment or memory. Mellow, slightly euphoric feeling because
of increased dopamine levels in the brain. Less inhibited. Less
shy. No depressant effects. Slight body warmth. A driver’s
ability to divide attention between two or more sources of visual
information can be impaired by BACs of .02 or lower.
.05 - .06 About two drinks per hour for a 160 pound man and a little over
one drink per hour for a 120 pound woman. Feelings of warmth,
relaxation, mild sedation, exaggeration of emotion and behavior.
Slight increase in reaction time, impaired judgment about
continued drinking. Visual and hearing acuity reduced. Slight
speech impairment. Loss of motor coordination begins. Mild
memory impairments such as forgetting someone’s name after
they’ve been introduced to you. Less alert. Increased feeling of
self-confidence.
.07 - .09 About 3 drinks per hour for a 160 pound man and less than 2
drinks per hour for a 120 pound woman. More noticeable
speech impairment and disturbance of balance. Impaired
coordination. Feeling of elation or depression. Definite
impairment in judgment and memory. Major increase in
reaction time. Increased urge to urinate due to suppressed
anti-diuretic hormone, ADH, which may cause the dehydration
that contributes to hangovers. Reduced visual sharpness,
speech, vision, and hearing.
.10 - .13 A little more than 4 drinks per hour for a 160 pound man and less
than 3 drinks per hour for a 120 pound woman. Noticeable
disturbance of balance. Uncoordinated behaviors. Major increase
in reaction time. Increased impairment of judgment and memory.
Possible embarrassing behaviors. Noisy. Mood swings.
.14 - .17 About 6-7 drinks per hour for a 160 pound man and less than 4
drinks per hour for a woman. Major impairment of all physical
and mental functions. Difficulty standing and talking. Distorted
perception and judgment. Cannot recognize their own level of
impairment. Blackouts are usually observed at BAC levels above
.15 but can occur at much lower BACs. Euphoria changes to
dysphoria. Clearly drunk.
.20 - .25 Less than 9 drinks for hour for a man and a little over 5 drinks per
hour for a woman. Confused or dazed. Major body movements
cannot be made without assistance. Disorientation. Apathy.
Lethargy. Exaggerated emotional states.
.30 - .35 More than 10 drinks per hour for a man and about 8 drinks per
hour for a woman. Minimal perception and comprehension.
General suspension of cognitive abilities. Many lose
consciousness. Inability to stand or walk. Vomiting. Stupor.
At very high doses, alcohol can suppress the activity of nuclei in
brainstem that control vital reflexes like gagging and breathing. A
common way for someone to die from the direct effects of alcohol
is to drink enough to suppress the gag reflex—they pass out on
their backs, vomit, and choke. Enough alcohol can shut down
breathing all together. The exact level at which humans die from
the direct effects of alcohol on the brain is not known for sure but
the evidence suggests that a BAC of .35 is the level at which 1 out
of 100 people would die.
.4 About 15.5 drinks per hour for a man and a little less than 10
drinks per hour for a woman. If consumption is spread over 6
hours, about 18.5 drinks for a man and 12 drinks for a woman.
Most lose consciousness. Loss of control of urine and bowels.
Some die.
.41+ About 16 drinks per hour for a man and more than 10 drinks per
hour for a woman. If consumption is spread over 6 hours, about
19 drinks for a man and about 12.25 drinks for a woman.
Breathing stops. Deep coma. Many die due to respiratory arrest.