Failed Breath Test but Sober? How to Prove Mouth Alcohol or GERD in Colorado

It’s possible to fail a DUI breath test in Colorado even when you’re completely sober. Conditions like acid reflux, GERD, or hiatal hernia can cause mouth alcohol that distorts breathalyzer results, making it seem like your blood alcohol concentration (BAC) is above the legal limit when it’s not. The alcohol vapors rising from your stomach or trapped in dental work can fool devices like the Intoxilyzer 9000, which measure breath alcohol rather than true blood alcohol levels.

If you’ve been charged with DUI after a questionable breath test, a skilled Denver DUI lawyer can help challenge the results. With medical documentation, dental evidence, and expert toxicology testimony, your defense can show the court that the reading came from residual mouth alcohol, not intoxication. This approach is crucial for protecting your license, record, and future.

Understanding How Breathalyzers Measure Blood Alcohol Content

Breathalyzers estimate blood alcohol concentration (BAC) by measuring alcohol vapor in a person’s breath. When alcohol enters the bloodstream, it is metabolized in the liver and then exhaled through the lungs. The device applies a 2100:1 blood-to-breath ratio, assuming that 2,100 milliliters of breath contain the same amount of alcohol as one milliliter of blood.

However, this ratio can produce inaccurate readings because not all alcohol in the breath comes from deep lung air. Alcohol vapor from the mouth, throat, or stomach, caused by acid reflux, dental work, or medications, can inflate results. Since the 2100:1 ratio is only an average, individual variations in metabolism, body temperature, and breathing patterns can also affect accuracy.

For Colorado drivers, these inaccuracies matter. Breathalyzer results directly impact DUI arrests and convictions, yet even small physiological differences can lead to false BAC readings and wrongful charges.

The Science Behind Mouth Alcohol Contamination

Mouth alcohol contamination occurs when residual alcohol lingers in the mouth or throat, causing breathalyzers to register BAC levels up to twice as high as the true value. The devices can’t distinguish between deep lung air and alcohol vapors from the oral cavity, leading to false positives.

This issue often arises after recent drinking, dental procedures, or reflux episodes. Alcohol can become trapped in dentures, crowns, or gum pockets, or return to the mouth due to GERD (acid reflux). Even mild burping or heartburn before a test can cause inflated readings.

Colorado law requires officers to observe the driver for at least 15–20 minutes before testing to allow mouth alcohol to dissipate. During this time, the subject must not drink, eat, smoke, vomit, or burp. When officers skip or improperly document this observation period, defense attorneys can challenge breath test reliability in DUI cases.

How GERD and Acid Reflux Cause False Positive Breathalyzer Results

Gastroesophageal reflux disease (GERD) and acid reflux can cause false positive breathalyzer results by allowing alcohol from the stomach to rise into the throat and mouth. When this “mouth alcohol” mixes with exhaled air, devices like the Intoxilyzer 9000 can’t tell it apart from deep lung air, showing BAC levels that don’t reflect actual intoxication.

Although Colorado requires a 20-minute observation period before testing, GERD episodes can occur silently without visible signs that an officer could detect. Medical studies confirm that reflux events can happen frequently and unpredictably, even hours after drinking.

Because alcohol remains in stomach contents for extended periods, a sober driver can still test above the legal limit if reflux occurs during the breath test. Medical evidence, such as a GERD diagnosis, pH monitoring results, or endoscopy records can help defense attorneys challenge the accuracy of the test and protect drivers from wrongful Colorado DUI convictions.

Common Medical Conditions That Interfere With Breath Test Accuracy

Diabetes creates acetone through a process called ketosis. This metabolic state happens when the body breaks down fat for energy instead of glucose. Breathalyzer devices read acetone the same way they read alcohol (ethanol). The machine cannot tell the difference between these two substances. People with diabetes who have ketoacidosis will show falsely high readings on breath tests.

Low blood sugar (hypoglycemia) creates similar problems by triggering the body to produce compounds that confuse the testing device.

Lung diseases change how breath tests work. Asthma, bronchitis, and chronic obstructive pulmonary disease (COPD) affect how well the lungs function. These conditions change breathing patterns and the amount of air left in the lungs after exhaling. The altered air flow creates unreliable test samples that may not show accurate blood alcohol concentration (BAC) levels.

Many common medicines cause false positive results. Asthma inhalers often contain alcohol-based propellants that stay in the mouth. Cold medicines and cough syrups include alcohol as an ingredient. Mouthwashes and breath fresheners contain high amounts of alcohol.

These products put alcohol directly in the mouth, which the breathalyzer detects even though the person did not drink beverages. Prescription medications for acid reflux, gastritis, and other digestive problems can push stomach contents into the mouth, raising test numbers.

Medical records from doctors, specialists, and hospitals serve as proof of these conditions. This documentation shows that health issues, not alcohol consumption, caused the high breath test reading.

Colorado DUI defense attorneys use these medical records to challenge breathalyzer evidence in court proceedings.

Substances That Can Trigger Mouth Alcohol Readings

Breathalyzers measure alcohol vapor in a person’s breath—not the alcohol in their bloodstream. Because of this limitation, certain everyday products and substances can trigger false positive breathalyzer results by leaving alcohol residue in the mouth.

1. Oral Hygiene Products: Mouthwash and rinses like Listerine or Scope contain up to 27% ethanol, similar to wine. Alcohol residue can remain on the tongue and throat for 15–20 minutes, causing inflated BAC readings if a breath test is taken too soon.
2. Breath Fresheners: Products such as Binaca spray, Listerine breath strips, and similar mints often use ethyl alcohol as a base ingredient. These compounds linger in the mouth and can make sober individuals appear intoxicated.
3. Medications and Inhalers: Common over-the-counter medications like Nyquil, cough syrups, and asthma inhalers may contain alcohol or produce chemical vapors mistaken for ethanol by breathalyzer sensors.
4. Tobacco Products: Chewing tobacco and snuff release natural alcohol-like compounds as they ferment. These residues stay in the mouth and between teeth, skewing test results.
5. Sugar-Free Products: Artificial sweeteners such as sorbitol and xylitol, found in sugar-free gum and mints, are “sugar alcohols.” Some breathalyzer models misread them as ethanol, leading to false BAC readings.
6. Chemical and Workplace Exposure: Workers exposed to paint thinners, solvents, acetone, or cleaning chemicals inhale volatile organic compounds (VOCs) that remain in the lungs and mouth. Breathalyzer fuel-cell sensors cannot differentiate these hydrocarbons from alcohol molecules.

Because of these risks, Colorado law enforcement officers must observe drivers for at least 15–20 minutes before testing to allow mouth alcohol to dissipate. Skipping this step can make breath test results scientifically unreliable and legally challengeable in court.

The 15-Minute Observation Period Requirement in Colorado

Colorado DUI law requires police officers to watch suspects without interruption for 15 minutes before giving a breath test. This waiting period protects the accuracy of breathalyzer results by stopping mouth alcohol from creating false readings.

Police officers must make sure the suspect does not do any of these things during the 15-minute watch period:

1. Eat food or drink liquids – Food and drinks can put alcohol residue in the mouth that affects test readings.
2. Smoke cigarettes or use tobacco – Tobacco products contain chemicals that interfere with how the breathalyzer machine measures blood alcohol content.
3. Burp or vomit – When a person burps or throws up, alcohol from the stomach comes into the mouth and changes breath test results.
4. Put anything in the mouth – Items like chewing gum, breath mints, cough drops, or pills can contain alcohol or substances that cause incorrect breathalyzer measurements.

When officers break this rule or fail to watch the suspect for the complete 15 minutes, the breath test evidence becomes unreliable.

Colorado criminal defense attorneys can ask the judge to throw out breath test results when law enforcement does not follow proper observation procedures.

Courts recognize that contaminated breath samples produce inaccurate blood alcohol concentration readings that should not be used as evidence against defendants charged with driving under the influence.

Documenting Your Medical History for Your Defense

Your complete medical records help challenge wrong breath test results in Colorado DUI cases. These healthcare documents show the court that certain health problems can cause breath testing machines to give incorrect readings. This evidence creates doubt about whether the test results truly show alcohol consumption.

Your lawyer needs these specific medical records:

1. Stomach acid problems (GERD or acid reflux) – Records from your gastroenterologist showing you had active symptoms when police arrested you. These medical conditions push stomach acid into your mouth, which breath testing devices can mistake for alcohol.
2. Recent dental work – Documentation from your dentist about procedures that used alcohol-based antiseptics or left open wounds in your mouth. Blood from mouth injuries contains compounds that breathalyzers read as alcohol.
3. Prescription medicines – A complete list from your pharmacy showing medications that contain alcohol (like cough syrups) or change how your body processes substances. Some diabetes medications and inhalers affect breath test accuracy.
4. Medical test results – Clinical proof from procedures like endoscopies or 24-hour pH monitoring that confirm ongoing digestive conditions. These objective measurements from medical equipment validate your health claims.

Your attorney must request these records right away. Hospitals and clinics delete old files after set time periods based on state record retention laws.

Medical records created at the time you received treatment prove more reliable than new doctor visits scheduled just for your court case. Courts view documentation from your regular healthcare before your arrest as more credible evidence.

Obtaining Expert Medical Testimony for Your Case

Medical experts help judges and juries understand why breath tests can show wrong results even when a person is sober. These doctors and scientists explain health problems and testing mistakes in clear terms that courts can understand.

A gastroenterologist (stomach doctor) can explain how acid reflux sends stomach contents into the mouth. This creates “mouth alcohol” that makes breath test machines give false high readings. The alcohol comes from the stomach, not from drinking.

A toxicologist (poison and substance expert) examines how the breath test was performed. They find problems like broken equipment, incorrect procedures, or sample contamination that caused wrong results.

A pulmonologist (lung doctor) shows how breathing conditions change test outcomes. Asthma, COPD, and other lung diseases affect how air moves through the body and can interfere with breath testing accuracy.

A forensic scientist reviews the breath test machine itself. They check calibration logs, maintenance records, and whether the device was working correctly on the test date.

These medical professionals review your health records and the testing procedures used in your case. They write reports and testify in court about their findings.

Getting these experts involved early helps build a stronger defense. Their medical credentials and scientific knowledge carry weight with judges and juries. They turn medical conditions from simple excuses into proven medical facts backed by science and documentation. This expert testimony challenges the prosecution’s claim that high breath test numbers always mean intoxication. The right expert can prevent wrongful convictions based on faulty breath test evidence.

Challenging the Calibration and Maintenance of the Breathalyzer Device

Breathalyzer machines need regular checks and upkeep to work properly. Police departments often skip the required steps listed by the companies that make these devices and by state laws. Defense lawyers can request maintenance records to find problems that make test results unreliable.

Important calibration problems to look for:

1. Skipped calibration schedules – The device manufacturer sets specific time periods for testing the machine’s accuracy, usually between 30 and 90 days, based on which brand and model of police use.
2. Missing maintenance records – When paperwork has blank spots or missing dates, this creates doubt about whether the machine worked correctly on the day officers tested you.
3. Quality control test failures – When the same breathalyzer unit fails accuracy checks multiple times, this shows ongoing mechanical or electronic problems with that specific machine.
4. Invalid technician credentials – State licensing boards require certification for any person who adjusts or repairs breath testing equipment, and these workers must follow approved step-by-step procedures.

Courts may throw out breath test evidence when maintenance records reveal these specific defects. Each breathalyzer unit has a unique serial number and maintenance history. This device-specific documentation either proves or disproves the accuracy of results from your particular test date.

Law enforcement agencies bear responsibility for keeping complete, accurate records that demonstrate proper device function. Missing or inadequate documentation weakens the scientific foundation of breath test evidence.

Police Protocol Violations That Invalidate Test Results

Police officers must follow strict rules when giving breath tests for alcohol. These rules protect the accuracy of test results and ensure fairness in DUI cases.

The Fifteen-Minute Observation Rule

Colorado law requires officers to watch suspects for fifteen minutes before administering a breath test. This observation period prevents mouth alcohol from affecting test accuracy.

During these fifteen minutes, officers must confirm that the person does not eat food, drink beverages, smoke cigarettes, vomit, or burp. The officer must maintain direct, continuous visual contact with the suspect throughout this period. Breaking this observation rule makes test results invalid in court.

Equipment and Testing Violations

Officers must use properly maintained breathalyzer devices that meet state standards. Common equipment violations include:

• Testing with machines that lack current calibration certificates

• Using mouthpieces past their expiration date

• Operating devices outside approved temperature ranges (typically 50-104°F)

• Failing to document test conditions and results accurately

Each breathalyzer instrument requires regular calibration checks to measure blood alcohol content correctly. Missing or incomplete calibration records undermine test reliability.

Documentation Requirements

Officers must keep detailed records of breath testing procedures. Required documentation includes maintenance logs showing regular service, calibration certificates proving device accuracy, and training records confirming officer qualifications.

Gaps in these records create legal grounds to challenge test validity. Defense lawyers examine arrest reports, body camera video, instrument maintenance histories, and officer certification records to find procedural errors.

Legal Consequences of Violations

Protocol violations provide grounds for suppression motions that exclude test evidence from criminal proceedings.

Defense attorneys use discovered procedural failures to support case dismissal requests or reduced charges.

Alternative Evidence That Supports Your Sobriety

Field sobriety test performance, witness testimony, and video recordings often contradict failed breath test results and demonstrate actual sobriety. Criminal defense attorney compiles thorough evidence packages that challenge the reliability of breath test outcomes when physiological conditions cause false readings.

Critical evidence supporting actual sobriety includes:

1. Police camera footage (dashcam and bodycam recordings) showing normal speech patterns, steady walking, clear answers to questions, and the absence of drunk behavior during the traffic stop.
2. Standardized field sobriety test results demonstrating satisfactory performance on standardized roadside tests like the walk-and-turn exercise and the one-leg stand balance test.
3. Witness statements from passengers in the vehicle or people who saw the incident confirming the driver’s sober behavior before and during the stop.
4. Driving pattern analysis showing no reckless behavior, proper staying within lane markings, and following traffic laws before the stop.

This collection of evidence creates reasonable doubt about whether the person was drunk. The physical evidence from multiple sources works together to paint a complete picture of the defendant’s actual condition during the DUI investigation.

When breath test results conflict with observable sobriety indicators, courts must weigh the credibility of chemical testing against documented behavioral evidence.

Building a Strong Defense Strategy With Your DUI Attorney

Knowing these legal cases from the past helps create a good defense, but you need to work closely with your DUI defense attorney to make it work. A complete defense plan starts with getting proof of your medical problems right away through doctor records, stomach test results, and medication history that shows GERD (acid reflux disease) or similar stomach conditions.

Your attorney needs to hire qualified scientists who study alcohol testing and can explain in court how breathalyzer machines have limits and how alcohol in your mouth can mess up the results. You must give your DUI defense attorney specific details about what you did before the test, like what you ate, when you burped, and what time you took your medicine.

Your defense team needs to question how the police did the testing by looking at officer training files, machine maintenance records, and whether they watched you for the required 15-20 minutes before testing. Winning your case means showing several different types of proof: medical records, scientific testimony, and mistakes in police procedures that work together to make the jury doubt the breath test results instead of relying on just one piece of evidence.

The breathalyzer device measures blood alcohol concentration (BAC) by analyzing breath samples. Police officers must follow specific DUI testing procedures set by the Department of Transportation and state law enforcement agencies.

Medical conditions like gastroesophageal reflux disease can cause stomach acid to enter the mouth cavity, creating false high readings. Expert witnesses with credentials in forensic toxicology explain these scientific concepts to judges and juries.

The observation period requirement exists because residual mouth alcohol from recent drinking, burping, or vomiting takes 15-20 minutes to disappear. Colorado defense attorneys examine calibration certificates, maintenance logs, and officer certification records to find procedural errors that violate defendant rights under criminal procedure law.