Breathalyzer 101: How to Fail the Test… Sober

IntoxilyzerThe Intoxilyzer 5000 breathalyzer machine doesn’t just catch drunk drivers. There are many factors other than alcohol that can influence a breathalyzer test result. As a result, many American drivers are at risk of getting a DWI, even if they haven’t been drinking.

How Does the Breathalyzer Work?

It is crucial to understand that the breathalyzer does not measure the alcohol content of blood. Only a blood test can measure blood content.

The breathalyzer actually measures electrical current. When a person has been drinking, this electrical current is produced when an ethanol (ethyl alcohol) is oxidized to acetic acid (vinegar) at the test site. The current is processed by the machine and then converted into an approximation of blood alcohol content.

Minnesota police use the Intoxilyzer 5000, an infrared radiation breath test machine. When a person breathes into the chamber, the device sends out an infrared beam of light through the breath sample. The machine then measures the wavelength of the beam of light. Chemicals oxidizing from the alcohol group absorb more light and will send a higher reading back to the machine.

The Breathalyzer and Diabetes

Acetone is a chemical compound naturally produced in the human body. It is also oxidized in the same way the body processes ethanol. The average person does not produce high enough levels of acetone to create a measurable reaction. However…

People with diabetes may have acetone levels hundreds or thousands of times higher than the average person. The infrared beam cannot distinguish between ethanol and acetone, so a person with diabetes could very easily get a false-positive breathalyzer test.

The Breathalyzer and the Low-Carb Diet

Diabetics aren’t the only people with high levels of acetone in their body. A ketogenic diet is a high-fat, high-protein, low-carb diet. The diet which burns the pounds rapidly also spikes acetone levels in the body. This can, and has, led to false-positive breathalyzer tests.

The Breathalyzer and Asthma Inhalers

Researchers have found that inhalers taken for asthma can produce high, inaccurate breathalyzer readings—even those inhalers without ethanol. In Spain, a research study on an infrared spectrometer (like the Intoxilyzer) produced startling results:

All of the test subjects had baseline results of zero. After a puff on the inhaler, every one of the participants had breathalyzer readings above the legal limit.

The Breathalyzer and Your Lungs

The infrared spectrometry breath test requires that a person breathe for 4-5 seconds, and that the volume of their breathe must be at least 1.5 liters. Studies have shown that people with smaller lung capacity can obtain highly inaccurate BAC levels or may be unable to register a reading at all and may be seen as refusing to test. Conditions that lead to smaller lung capacity include:

  • Bronchitis
  • Asthma
  • Emphysema
  • Fibrosis
  • Scoliosis
  • Any other congenital lung disease

The Breathalyzer, Fumes, and E85

In a study of fumes on the Intoxilyzer 5000, researchers sprayed paint in a room for 20 minutes while a subject wore a protective mask. The subject, a professional painter, was then given a breath alcohol test. Although a blood test showed no alcohol, the breathalyzer reading was 0.075—barely under the legal limit.

This study could also prove problematic for the growing number of drivers using E85 to fuel their vehicles. The ethanol-based fuel produces ethanol emissions which, if inhaled, could alter BAC results.

The Breathalyzer and Acid Reflux

People suffering from gastroesophageal reflux disease (GERD) have an increased risk of getting a false-positive result above the legal limit on a breath-alcohol test. Even if only a very small amount of alcohol is consumed, many GERD patients have tested above the legal limit of 0.08, placing them in danger of a DWI conviction.

Because of all the above factors it is essential that you contact a DWI defense lawyer if you are ever arrested for drunk driving.

Related sources:
Clean Air Trust
ABA Journal
University of Washington
St. Louis College of Pharmacy (British Medical Journal)
International Journal of Obesity

The following two tabs change content below.

Avery Appelman

Avery Appelman is a criminal defense lawyer and the founder of Appelman Law Firm. While his practice is primarily recognized for its work with DWI and related offenses, he has 16 years of experience working with clients on drug, assault, theft, traffic, criminal sexual conduct, and prostitution charges.


  1. marc Bonney says

    I’m a truck driver who recently was made to take a breathalyzer and blew off false positive.The ttest took place in Maine after I hadn’t drank any alcohol for more than 40 hours. If my employer puts this on my record my career as a driver is pretty much finished. Any chance of suing my employer?

Leave a Reply

Your email address will not be published. Required fields are marked *