The Problems with Urine Tests and DUI Charges

An alcoholic drink next to a set of keys
Driving while under the influence of alcohol or drugs can have serious legal consequences, and for a good reason: impaired drivers are a real threat to themselves and others. Accordingly, numerous tests gauge whether a suspected driver is indeed under the influence, and to what extent. However, like many types of tests, it is possible for a false-positive to arise, resulting in unfair DUI charges. In such cases, it is necessary to have an experienced and knowledgeable DUI defense lawyer who can help bring to light why the charges are unjust.

In the case of urine testing, multiple factors may lead to a false-positive result. Aside from human error during testing, a few assumptions about the driver may be made while administering the test or interpreting its results. Don’t allow one test to tell your story for you; let our Phoenix legal team represent your case equitably.

Why Are Urine Tests Administered?

When someone is suspected of driving under the influence of alcohol, a breathalyzer test is usually used first, sometimes in conjunction with other physical tests to gauge one’s cognitive abilities. If a breathalyzer is unavailable or the results do not reflect an officer’s suspicions, a urine test may be administered. In cases where a driver is suspected of driving under the influence of drugs, a urine test may also be administered, as a breathalyzer only reflects blood alcohol content (BAC).

Of the three DUI tests used – breathalyzer, urine tests, and blood tests – most experts agree that urine tests are the least reliable. And yet, they continue to be implemented in cases where drivers are suspected of being under the influence, leading to instances of law enforcement only using the test to supplement their suspicions – not as an objective assessment of one’s condition while driving. This becomes even more problematic when urine tests are used in lieu of other evidence, telling an incomplete and often biased story.

Common Problems with Urine Tests

The first and most immediate problem with urine tests is that they inherently rely on estimation. Whereas breathalyzers directly reflect BAC, urine tests use an algorithm that does not always accurately measure blood-alcohol content. Alcohol content in urine is estimated to be about 1.33 times that of BAC, and so the number derived from a urine test is divided by 1.33 to arrive at one’s estimated BAC. However, this conversion rate is only an average. In fact, some people actually have less alcohol in their urine than in their blood, making this test wholly unrepresentative of their BAC at the time. This dilemma becomes even more convoluted when considering time of alcohol consumption, other (non-alcoholic) drinks imbibed, and the previous time of urination. While these factors make little difference in a breathalyzer test, they can greatly skew the apparent results of a urine test.

When it comes to drugs, urine tests can also tell an inaccurate story. For starters, a survey by the National Institute of Drug Abuse found that 20 percent of labs reported the presence of drugs in a round of drug-free samples. Many otherwise safe pharmaceuticals, such as Advil® or cough syrup, have a history of leading to false-positive drug tests.

Furthermore, urine tests are not used to determine when a drug has been taken – only that the remaining metabolites are present. Even if a driver did, for instance, use marijuana in the past few days, this does not mean the drug was used directly prior to driving. 

Fighting DUI Charges

A single DUI can result in steep consequences: a fine of at least $250, the installation of an ignition interlock device, additional alcohol and drug screening, or even license suspension. An innocent driver shouldn’t be faced with even the possibility of such inconvenience. Given the severity of DUI charges and what they can mean for someone both personally and financially, it is important to work with a lawyer who intimately understands the ins and outs of DUI laws. When you consult James E. Novak, you benefit from his experience as a former prosecutor and many cases within criminal and DUI law. By investigating every detail of your case and the evidence collected against you, he will work tirelessly to ensure that you are fairly represented.

Schedule a Consultation

If you have been unfairly charged with a DUI or similar driving offense, contact our office to schedule a consultation. The sooner you allow us to look into your case, the better we can represent you.

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