General Alcohol FAQs

I followed the Arkansas State Police guide of 1 drink per hour. Why did I register over a .08%?

Alcohol begins absorbing into the blood stream as soon as it enters the mouth, but most alcohol is absorbed through the small intestine. Until the alcohol has passed through the small intestines and into your blood stream, it really has not entered your system in such a way that it will affect you or your BAC.  Before alcohol gets to your small intestine, it must pass through your stomach by the process of digestion.  There are numerous factors that can affect the rate at which alcohol is absorbed into your system, and therefore also affect the rate at which your BAC lowers or rises.  Food, especially those high in starches or fats, slow down the transfer of alcohol from the stomach to the small intestines. Persons with certain digestive ailments can have a different absorption rate than the normal person.  Shock (for example, from an injury in an accident) can also slow down the absorption period. Also, straight alcohol on an empty stomach can result in pyloric shock which can significantly slow down the absorption of alcohol. If the absorption rate is slowed for any reason, you could have several drinks hitting you at once without the benefit of having any eliminated from your system. The guide of 1 drink per hour could also be misleading because it does not take into consideration the high alcohol content of some alcoholic beverages or the weight of the person drinking. The state police recommendation is based a 1 oz. shot of 86 proof alcohol or a 12 oz beer. If you are drinking a higher proof liquor, a malt beer, or a mixed drink with more than one shot of alcohol, then you fall outside the suggested guidelines. Drink size is also important. A 16 oz. cup filled with half alcohol and half coke is the same as 6 1 oz. shots of the same alcoholic beverage.

How long does it take to absorb alcohol into the blood stream?

The average absorption rate ranges from 30 minutes for an empty stomach to 90 minutes with food in the stomach. Some studies have suggested it can take up to 6 hours for alcohol to absorb after suffering from shock or eating certain foods. Others say that everyone should be fully absorbed within 30 minutes. Our attorneys’ research has uncovered no studies that suggest alcohol can be absorbed in less than 20 minutes. It is safe to say it varies considerably in every person. It will even vary in the same person from one time period to another. You must consider absorption rate prior to driving to avoid a DWI. You may feel fine when you leave the place where you have had your drinks but if you have recently consumed alcohol, your BAC will be climbing and you will be at risk of being arrested for a DWI or DUI.

How long does it take for alcohol to leave my system so I will not get a DWI?

The average person will eliminate alcohol at a rate of .015 per hour.  This rate varies, but .015 is the generally accepted elimination rate. Keep in mind alcohol must be absorbed before the body begins eliminating it.   

How long does alcohol stay in my system?

This seemingly simple question requires a complex answer. It doesn’t matter if you drink beer, whiskey, vodka, wine, or some other alcoholic beverage, there is no set time limit for how long alcohol stays in your system. The ethanol must be absorbed. As discussed in another section, the absorption is different for each person and can even vary from day to day for an individual.  While the alcohol is absorbing, your body is also eliminating alcohol a rate of  approximately .015 per hour. The only way to determine when your body is alcohol free is to know your specific blood alcohol content when you start.  For example, if my blood alcohol is .12% at 4:00 am and I have fully absorbed my last drink, I can assume that at 7:00 am my blood alcohol content would be approximately .075%. Keep in mind that sleep does not make you sober. Unfortunately, our firm has represented a number of individuals for DWI or DUI who were arrested in the morning because they still had enough alcohol in their system from a night out, causing them to have a blood alcohol content over the legal limit several hours after they stopped drinking.

What can affect the blood alcohol content (BAC) of a person, other than the number of drinks I have?

There are many variables that affect blood alcohol content.  No two people will process and eliminate alcohol at the exact same rate.  A person’s body weight affects their BAC because a larger person has more blood volume. This causes their BAC to be lower than a smaller person drinking under the same circumstances because BAC is measured as a percentage of alcohol in the blood.  For example: A 100lb person can drink 1 drink in a 1 hour period and have a BAC of .04%. A 160lb person having the same drink will register a BAC of .02%.  Gender is an important distinction because women’s bodies do not process alcohol as quickly as men’s bodies, so even if a man and a woman are the same body weight and they drink the same drinks at the same time, the woman’s BAC will almost always be higher than the man’s because of the slower absorption and elimination rates.  Some of the other factors that affect the BAC of a person include:  the alcohol content of the drinks; time spent drinking; food eaten before or after drinking starts, etc.

What breath testing machine is currently in use in Arkansas?

Arkansas now uses the EC/IR II.  It is made by Intoximeter, Inc. in St. Louis.  It is an electro-chemical based test with an infrared mouth alcohol detector.  The electro-chemical portion of the test is the only portion that quantifies alcohol.  There have been a number of problems with the EC/IR II.  More than half of the machines purchased in Arkansas had to have their barometers replaced within the first couple of years in use.

Are breath tests accurate?

To answer this question we must first understand the science behind breath alcohol testing.  When you blow into a breathalyzer it captures a breath sample that is assumed to be what is considered “end breath” or breath that comes from the deepest part of the lungs.  The machine uses this sample because it has the highest alcohol concentration and is (hopefully) made up of lung air with no residual mouth alcohol.  Here is a list of just a few problems with breath testing.

Mouth alcohol, if not detected, can result in an outrageously false high reading making the result very unreliable.  

Another source of error is breathing pattern.  Hypo-ventilation can result in a reading that is roughly 15% higher than the test subject’s true BAC.  In contrast, hyper-ventilation can result is a reading roughly 10% lower than the test subjects true BAC.

Breath temperature can result in an erroneous reading of BAC.  The average person’s breath is 34 degrees Celsius.  For every one degree Celsius the breath temperature is elevated the breath result will over estimate BAC by 8.6%.

Testing during the absorption phase can over-estimate BAC by up to 200%.  That is, blowing while alcohol is still absorbing.  It takes roughly 30-90 minutes to fully absorb alcohol.  This means that if you are drinking while in the car or have just left your place of drinking, your breath test will be higher than your BAC at the time you were operating the vehicle.

Blood/breath partition ratio is another source of error, but is very complicated and would be best explained by one of our Arkansas DWI attorneys in person.  

Breath testing is based on averages and none of us are truly average.  Though the machine itself may be functioning properly and without error, it can still produce results that are not reflective of a person’s true BAC.

Should I take the breath test?

There are many factors to consider when deciding to take the breath test.  It is a violation of law to refuse the breath test in Arkansas, therefore it is unlawful for our attorneys to advise you not to take the test.  There are many things to consider when trying to reach the decision.  The various factors include:  the potential errors listed above, the penalties for refusing (the penalties in Arkansas are the same for refusal as they are for being arrested for DWI with a BAC test), any particular medical conditions you may have that can effect the result, etc… It would be impossible for us to advise you unless we had been with you all day and knew your medical history.  If you blow, you should always demand a blood test.

Are blood tests accurate?

Yes, if done properly.  There are many, many factors that can effect the accuracy of a blood test.  Blood tests are the only chemical tests in Arkansas that can be legally refused.  The following are a list of questions that our DWI attorneys would ask to determine if the blood test was done accurately.  Did they use a non-volatile prep prior to collection? Was there any hemolysis at the collection site? Did they use the proper needle size? Did they collect in a gray top tube? Did they invert the tube as directed by the manufacturer to properly mix the required compounds? Did they refrigerate at a constant temperature in storage? Is it your blood that is tested? Is there a proper chain of custody? Was the gas chromatograph properly calibrated?  Did they run blanks? Did the analyst follow the method established by the department? Was there contamination of the sample or the machine? There are a number of possible causes for a reported result that is falsely high.  Call one of our Arkansas DWI attorneys to discuss further.

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