Variables That Can Affect DUI Breath or Blood TestsAn arrest for DUI in Knoxville can be frightening for many reasons. You may have had a drink or two and felt you were okay to drive. You may have had an accident or were pulled over for suspicion of driving under the influence. No matter what the circumstance, it happened. Likely you submitted to breath or blood testing to determine your blood alcohol content (BAC).

What you may not be aware of is that there are many variables affecting the outcome of BAC tests. The reliability of blood and breath testing to determine BAC greatly depends on whether the tests were administered properly, and whether the machines used were functioning correctly. If your testing wasn’t done accurately or under appropriate circumstances, this can be used in your DUI defense.

Breath testing for DUI

Believe it or not, breath testing is not infallible, and many errors can occur during the test. Sometimes the person being tested has health issues that can negatively affect the test results, including things like asthma, diabetes, bronchitis, ketosis, emphysema, or dental problems. There are also technical issues that could affect a breath test:

  • The machine must be at the correct operating temperature
  • A deep lung sample must be provided
  • External environmental causes (like bad air quality) can cause inaccurate results
  • The machine and equipment must be properly calibrated, cleaned, and maintained to give accurate results
  • Sometimes police radios can cause frequency interference with test equipment
  • Mouthwash, lipstick or lip balm, and other grooming items have been known to affect breath test outcomes

Blood testing for DUI

Blood testing is considered to be the most accurate form of testing for BAC, but this test is also fallible. Following are some of the factors that could affect the validity of a blood test:

  • Improper methods of drawing blood
  • Faulty or contaminated medical equipment
  • Untrained technicians
  • Improper transport or storage of sample
  • Inaccurate results due to medications in patient’s blood, like anticoagulants

You always have the right to refuse breath or blood testing, but remember if you do there can be consequences like suspension of your driver’s license. If you are arrested for DUI, it’s in your best interest to contact an attorney before taking any tests or making any statements.

When you’re facing a driving under the influence charge, you need the best defense possible. The experienced Knoxville DUI lawyers at Banks and Jones know how to challenge these chemical tests and can work with you to get the charges against you reduced or dropped. Our legal team is standing by. Give us a call at 865-546-2141. You can also make an appointment by completing our contact form. Fight 2 Win!

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