Breath Test Defenses

Possible Breath Test Defenses for San Diego DUI


  • You have witnesses who can prove sufficient alcohol was consumed while driving just prior to stopping, after the drive stopped, or prior to arrival of police
  • Rising blood alcohol level showing time of driving BAC would have been lower than time of testing
  • State can not establish BAC test was done within three hours after driving stopped, so no legal presumption of .08% BAC at the time you were driving
  • No two breath test results within 0.02% of the other – .10% and .08% are within .02% but .11% and .08% are not
  • Cop obtains initial BAC result .07% or less, then retests after waiting, getting result .08% or more
  • Cop not properly trained in accordance with the breath test standards [Title 17 of the California Code of Regulations]
  • Cop does follow manufacturer’s manual or training protocol
  • Insufficient or inadequate machine inspections
  • Margin of error or inherent sampling variability (e.g., 0.088% reading with +/- 0.01% acknowledged precision issue)
  • Proof of irregular blowing pattern (artificially high water vapor problem caused by crying and blubbering)
  • Breath temperature elevated (as a result of proof of fever, hot tub, sauna, detention in hot sun during summer)
  • Proof of falsely elevated results as a result of chemical interference not flagged by machine because, prior to testing, you just had substantial environmental exposure to volatile fumes (gasoline, lacquer, dry cleaning fluids, paint)
  • Tyndall effect after air bag opened – fluid build-up from caustic gas propellant; lung and airway irritation; diffusion of light; propellant exposure; cut lips
  • Proof of something in mouth which has alcohol or established contaminating/interfering substance not flagged by machine, just prior to blowing
  • Testing area and circuitry create Radio Frequency Interference from equipment such as a cop radio, copy machine or machinery with surge capabilities) causing instrument to produce artificially high reading; undedicated (not clean) shared power supply with heater or major appliance
  • Cop does not do continuous observation of you for entire 15 minutes just prior to your first blow (Cop includes transportation time in observation time, goes into vehicle trunk, walks around to get you before testing and takes you to machine without 15 minute continuous observation, or leaves you alone at anytime during 15 minutes prior to testing – you used toilet or were placed in cell or a room alone).
  • During the 15 minutes before the test, you burp, belch or slight regurgitation of gas
  • Vomiting, belching within 15 minutes of test – no rinsing of mouth, or inadequate deprivation period before retest
  • Proof of diabetes, causing conversion of high acetone levels into isopropyl alcohol
  • Proof of unchecked gastric reflux or hiatal hernia condition (Gastro Esophageal Reflux Disease or severe Acid Reflux Syndrome) fully diagnosed by cooperating doctor who treated just prior to DUI arrest
  • Proof of ongoing strict high protein only diet followed by abrupt introduction to carbohydrates just prior to arrest, triggering auto-generated alcohol production causing ketones to be converted to isopropyl alcohol aka “auto-brewery” syndrome
  • Proof of major dental condition – severe gingivitis, gum disease actually trapping mouth alcohol to contaminate a sample result
  • Cop ignores your specific request for a subsequent testing of your blood and testing is available
  • Cop commits serious crime during DUI (obstruction of justice) to conceal evidence, or makes an illegal stop and arrests you without probable cause
  • FIRMD – cop gets fired, indicted, retires, moves far away, or dies
Breath Test Defenses April 22, 2015

San Diego DUI Attorney

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