Alcohol: Pharmacokinetics, BAC

Pharmacokinetics of Alcohol, BAC, Effects At Specific B.A.C. Levels

When alcohol enters your body, it isn’t digested like most substances. It’s absorbed quickly, and is seen as a toxin, so your body therefore will primarily use the liver to metabolize the alcohol. And while I don’t want to give a full biology lesson here, the liver works at about a “drink an hour” pace (which is where that age-old rate of recommended consumption likely comes from). Until it’s all metabolized, it’s all over your body, in your blood, visiting your brain, etc (3). And, of course, because it’s in your blood, it’s therefore in your lungs. This is the cause of the alcohol breath that most people refer to. In simple terms, it’s “in the process of being processed” alcohol, and it has a distinct, somewhat sweet, odor. You probably know the smell I’m talking about (it’s also why the “alcohol smell” on someone intoxicated will smell remarkably similar, regardless if the alcohol consumed was whiskey, beer or wine coolers. Interesting huh?)

This is precisely how a breathalyzer can measure blood alcohol level for law enforcement purposes — the device measures how much “unprocessed” alcohol there is in your body.

So that answers our first two questions — just what is the smell, and why is it so hard to get rid of? The smell is hard to get rid of because they don’t make breath mints for your lungs. Another interesting thing I came across is that like the alcohol in your blood, it’s also excreted in sweat coming from your pores (4) — literally, someone drinking heavily might “smell” of alcohol, without you even smelling their breath. (So that’s why Uncle Ernie always had that peculiar smell!)

Now let’s answer the third question: what is that smell the morning after? Well, as an NYC Cosmetic Dentist, I’m well-qualified to answer that one. It’s plain old “bad breath.” See, alcohol dries out your mouth. A lot of alcohol really dries out your mouth. And bacteria simply love a really dry mouth (devoid of all that pesky saliva), and will thrive in such an environment. That’s often confounded with the fact that many people who consume a few too many might go to bed without brushing their teeth, which leaves all kinds of foodstuffs for the bacteria to interact with. And if you had something to smoke, too? That’ll contribute to “morning mouth,” as well.

The effects of alcohol intoxication are greatly influenced by individual variations among users. Some users may become intoxicated at a much lower Blood Alcohol Concentration (BAC) level than is shown.

A BAC describes the amount of alcohol in a person's blood, expressed as weight of alcohol per unit of volume of blood. For example, 0.08 percent BAC indicates 80 mg of alcohol per 100 ml of blood. For most legal purposes, however, a blood sample is not necessary to determine a person's BAC. It can be measured more simply by analyzing exhaled breath.

0.02-0.03 BAC: No loss of coordination, slight euphoria and loss of shyness. Depressant effects are not apparent. Mildly relaxed and maybe a little lightheaded.

0.04-0.06 BAC: Feeling of well-being, relaxation, lower inhibitions, sensation of warmth. Euphoria. Some minor impairment of reasoning and memory, lowering of caution. Your behavior may become exaggerated and emotions intensified (Good emotions are better, bad emotions are worse)

0.07-0.09 BAC: Slight impairment of balance, speech, vision, reaction time, and hearing. Euphoria. Judgment and self-control are reduced, and caution, reason and memory are impaired, .08 is legally impaired and it is illegal to drive at this level. You will probably believe that you are functioning better than you really are.

0.10-0.125 BAC: Significant impairment of motor coordination and loss of good judgment. Speech may be slurred; balance, vision, reaction time and hearing will be impaired. Euphoria.

0.13-0.15 BAC: Gross motor impairment and lack of physical control. Blurred vision and major loss of balance. Euphoria is reduced and dysphoria (anxiety, restlessness) is beginning to appear. Judgment and perception are severely impaired.

0.16-0.19 BAC: Dysphoria predominates, nausea may appear. The drinker has the appearance of a "sloppy drunk."

0.20 BAC: Felling dazed, confused or otherwise disoriented. May need help to stand or walk. If you injure yourself you may not feel the pain. Some people experience nausea and vomiting at this level. The gag reflex is impaired and you can choke if you do vomit. Blackouts are likely at this level so you may not remember what has happened.

0.25 BAC: All mental, physical and sensory functions are severely impaired. Increased risk of asphyxiation from choking on vomit and of seriously injuring yourself by falls or other accidents.

0.30 BAC: STUPOR. You have little comprehension of where you are. You may pass out suddenly and be difficult to awaken.

0.35 BAC: Coma is possible. This is the level of surgical anesthesia.

0.40 BAC and up: Onset of coma, and possible death due to

respiratory arrest.

Once in the bloodstream, alcohol leaves the system in two ways:

10% leaves through breath, perspiration, and the urine.

90% is metabolized (broken down in the body).

Pretty much everyone, regardless of age, size, or race, metabolizes alcohol at the same pace. That pace is .015 of blood alcohol concentration (BAC) per hour. So that means for every hour you are not drinking, .015 of the alcohol in your body is being metabolized and disappearing from your body (thanks to David J. Hanson, Ph.D. for this information). So, if your BAC was 0.08 (legally impaired), it would take about 5.33 hours for the alcohol to be eliminated from your body.

So starting from a BAC of 0.08….

After 1 hour – your BAC would be 0.065

After 2 hours – your BAC would be 0.05

After 3 hours – your BAC would be 0.035

After 4 hours – your BAC would be 0.02

After 5 hours – your BAC would be 0.005

Alcohol would be eliminated from the body at about 5 hours and 20 minutes (the body metabolizes alcohol at the rate of about 0.005 per twenty minutes, as 0.005 x 3 = 0.015).

So it is easy to tell when your body will be free of alcohol. It is not so easy to tell, however, what your BAC is if you do not have some kind of alcohol tester, be it a breathalyzer or a disposable alcohol test.


Getting to a BAC of 0.08 is not that difficult. For a 140 lb man, it would be 3 drinks in one hour. If someone is binge drinking, they could get into a situation where alcohol remains in their body for 10 hours or more.

The removal of ethanol (drinking alcohol) through oxidation by alcohol dehydrogenase in the liver from the human body is limited

Usually: 7 gram of alcohol per hour is removed.