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Breath Tests: Common But Often Inaccurate

In every state, a driver with a blood alcohol concentration (BAC) of .08 or higher is presumed to be legally intoxicated. Each state has also enacted an implied consent law. Implied consent laws state that every licensed driver is considered to have given his or her consent to chemical testing to determine his or her BAC whenever a law enforcement officer has reasonable suspicion of intoxication. In Georgia, refusal to submit to such a test results in license suspension or revocation.

While a blood test is arguably more reliable, the breath test for BAC is more commonly used in the field because the testing equipment is convenient to transport and the test is easier to administer, can be used by nonmedical personnel, is less physically intrusive to the person taking the test and produces results more quickly. Under certain circumstances, however, breath tests are less than reliable.

Breath Test Vulnerabilities

A drunk driving defendant, usually through an experienced attorney and often with the help of a scientific expert, may be able to challenge the breath test results in his or her case. Several factors may affect the reliability of the results.

Arguments that a drunk driving defense lawyer may make to undermine the breath test results include:

  • The breath test’s assumption of a 2100-to-1 blood-to-breath ratio may not be scientifically reliable.
  • The test was not administered correctly; for example, the administrator did not warm up the machine to the correct operating temperature or ensure an adequately deep lung sample.
  • The test administrator was not properly trained or qualified.
  • The equipment was not maintained properly, calibrated correctly or cleaned adequately.
  • The result was affected by some characteristic of the driver such as age, lung function or a medical condition such as asthma.
  • The test administrator did not continuously observe the driver for an adequate period before the test to prevent him or her from putting anything into his or her mouth that could affect the result.
  • Police radio operation generated electromagnetic waves, causing radio frequency interference (RFI) with the testing equipment.
  • The driver was exposed to a gas or vapor before the test that made it unreliable, such as during painting, floor sanding, varnishing or another activity with chemical exposure.

This long list of potential problems with breath test results is far from complete. If a person charged with drunk driving is able to show that something affected the reliability of the test results, the state will need to rely more on other types of evidence to prove intoxication.

Speak To A Drunk Driving Defense Lawyer

If your situation involves a breath test to measure BAC, an experienced attorney from Andrews & Sanders Law Offices in Savannah can provide valuable advice and representation. Call 912-341-6861 for a free phone consultation or contact us online.