Blood and Breath Tests

Under California’s Implied Consent Law, all persons who obtain a California driver’s license give their consent to take a chemical test if suspected of driving under the influence (DUI).

There are three types of chemical tests — blood, breath and urine.  Of the three chemical tests, the blood test is considered to be the most reliable in determining blood-alcohol-content (BAC) levels.

Alcohol Absorption

Blood alcohol testing measures the amount of alcohol (ethanol) in the human body.  Alcohol is not digested as other things that we consume are.  Rather, alcohol is absorbed unchanged directly into the stomach lining.  Once alcohol (ethanol) is consumed, it is absorbed into the body’s blood stream, as well as into various tissue and cells.  The alcohol then begins to metabolize.  It metabolizes differently from one person to the next and is dependent upon an array of factors, including a person’s gender, metabolic rate, weight, etc.  The amount of alcohol that is absorbed and metabolized in the blood reaches its peak level approximately one hour after drinking.  However, if a person was eating while drinking alcohol or ate after doing so, the time it takes to reach its peak level increases.

Because it takes time for the human body to absorb and metabolize alcohol and because blood alcohol testing of a suspected DUI offender often takes place an hour or more after a person last consumed an alcoholic beverage, blood alcohol testing does not provide conclusive evidence of what a person’s true BAC was at the time he or she was “driving.”  Both prosecutors and even toxicologists have conceded that they can not state with any real certainty what a person’s BAC was at the time they were “driving.”  This, of course, opens the door for the defense.  Furthermore, toxicologists have even admitted that differences between 3% and 10% may likely occur.  What this means is that even if a person’s BAC was .08% at the time a blood sample was given, his or her BAC could have actually only been .05% when driving.

About Blood Alcohol Testing

The accuracy of blood alcohol testing is not infallible, as has already mentioned.  However, in addition, any number of errors can occur that may result in an accurate BAC reading.  Most errors found with blood alcohol testing stem from the test’s being improperly administered. When administering a blood alcohol test, the blood is supposed to be drawn directly into a glass vial or tube that contains an exact amount of preservative and anticoagulant.  If these precise levels of both substances are not present, then the blood sample can actually ferment, resulting in an inaccurate result.   In addition, even the type of swab used to disinfect the draw site is an important issue.  The professional who draws the blood is supposed to use a non-alcohol swab.

As with all evidence collected, proper procedures and a proper chain of evidence must be followed.  However, errors are sometimes made, and a skilled Orange County DUI lawyer will always conduct a thorough investigation to see if such errors occurred.  If errors are found, then most often any result from the blood test can be suppressed in court.

About Breath Alcohol Testing

The fastest and easiest way for law enforcement to obtain a BAC reading is through the use of a breath alcohol testing device.  In California, there are two basic types of breath testing machines that are regularly used by the police.  The first is the preliminary alcohol screening (PAS) breath test.  In administering the PAS test, the police utilize a hand-held field breathalyzer that runs off a 9-volt battery.  It is important to note that this particular breathalyzer test is voluntary.  The PAS testing devices are only able to determine the presence or absence of alcohol.  While this is incredibly convenient for the police, accuracy as to the amount of alcohol in a person’s blood stream is not reflected with this test.  The second type of breath alcohol testing machines used by law enforcement are more sophisticated than the PAS device and tend to be a little more accurate in measuring BAC.  This type comprises the commonly used BAC Datamaster, the Intoxilyzer, and the Draeger.  However, everything from body temperature, electrical frequencies, calibration, and maintenance of the device can have an impact on the test results.

Errors with Breath Testing

There are many basic flaws associated with breath testing devices.  In theory, breath testing machines are supposed to reflect a person’s BAC accurately; however, it has been proven that this is not always the case.  Across the country, drunk-driving defense attorneys have shown that these machines are prone to errors and a number of problems exist in relying on their results.  If a breath testing device is not properly calibrated, the results can be artificially inflated.  In addition, factors such as changing air temperature, radio frequencies, and even the presence of peppermint, onions, pizza, and carbonated soda that contains fruit flavoring can have an impact on the test result.  Furthermore, many physical conditions such as acid reflux and dental diseases can provide an inaccurately high result.

Get Help from an Experienced Orange County DUI Lawyer

Only a qualified Orange County DUI attorney who is familiar with blood alcohol testing and breath testing machines will be able to provide you with the best possible defenses.   As highly-skilled and experienced Orange County DUI attorneys, we know how to find out if a blood sample has been tainted and/or the results not properly analyzed.  We will conduct a thorough investigation into how testing was administered and where it was administered and if any errors are found, we will quickly seek to have the test results thrown out.

We offer free Orange County DUI case reviews.  Your freedom is important.  Contact us today!