This article is designed to be used for educational or informational purposes only. The information in this article is not designed to be a substitute for legal advice from an attorney. Any individual who plans on drinking alcohol and driving an automobile should rethink their plans and find a safer way to travel. Any individual who needs legal advice regarding the use of alcohol and operating a motor vehicle should consult with a licensed attorney.
According to the Companion Encyclopedia of the History of Medicine, in the 1920s, authorities began to wonder how alcohol impaired a person’s driving ability and how they could test the level of alcohol in an individual’s system. In the 1930s, the chemist Rolla Neil Harger demonstrated that the amount of alcohol in a person’s breath was proportional to the alcohol in their blood and developed an instrument labeled the drunkometer to measure intoxication in individuals who were driving. This machine relied on a chemical solution that oxidized alcohol, resulting in a purple liquid in the device turning clear. The color change indicated that the person had alcohol their system.
Later, in 1954, American chemist Robert F. Borkenstein developed the breathalyzer using a similar oxidation technique. Even though the breathalyzer was a brand name at the time, this name has come to be used for any instrument that measures an individual’s blood alcohol concentration (BAC) via the alcohol in the breath. Subsequently, other types of breathalyzers have been developed to measure BAC in individuals suspected of being intoxicated while driving.
Traditionally, portable breathalyzer tests (PBTs) used semiconductor oxide sensors to measure a person’s BAC. These types of PBTs are subject to false positives and more appropriate for personal use than for law enforcement. PBTs that use fuel sensors have more accuracy and are more commonly used by law enforcement officers.
Factors That Can Affect PBT Accuracy
There are several factors that can affect the accuracy of a portable breathalyzer test, and attorneys are almost always ready and willing to challenge PBT results. For example, PBTs measure deep lung air, and not blowing hard enough into the machine may result in inaccurate readings; however, police officers are trained to ensure that the person blows into the machine properly, or they will simply just arrest the person if they cannot get them to cooperate.
There are other potential confounding factors that can affect PBT accuracy.
- Any foreign substance in the mouth that contains alcohol can produce a positive reading on a PBT. Breath fresheners, certain mouthwashes, cough medicines, etc., can lead to inaccurate results if the goal is to test the person’s BAC and not the alcohol in their mouth.
- Even environmental factors, such as paint thinner fumes in the air, can affect the results.
- PBTs must be calibrated at specific times, and the batteries must be replaced frequently in order to preserve accuracy.
- Software bugs, other malfunctions, and other glitches can lead to potential inaccurate readings.
- Certain physical conditions, such as diabetes, liver disease, or certain types of cancer, may affect the results.
- Some respiratory conditions may affect the results.
- If a person has eaten certain types of food, the results may be affected.
- Human error can result in inaccurate readings, including not administering more than one PBT. Improper training, failure to heed correct procedures, only taking one reading, etc., can produce potentially inaccurate results. Multiple readings are desired for overall accuracy.
Attorneys often scrutinize PBT results very closely in order to find inconsistencies and instances that can question the validity of the results.
What Happens if Someone Refuses a Portable Breathalyzer Test?
Most legal sites advise against taking portable breathalyzer tests and field sobriety tests unless someone is actually sure they are not intoxicated. If a person has only consumed alcohol at the rate of one drink per hour or less, it is likely that they will pass a PBT.
However, even if the person is under the level of legal intoxication (0.08%), they may be arrested for impaired driving or some other alcohol-related driving offense. Police officers have the discretion to arrest someone who has any amount of alcohol in their system if they believe the person is a danger to themselves or others. Since most traffic stops for suspected DUI occur due to some irregularity in driving, the officer will most likely arrest the person anyway.
Refusing to take a portable breathalyzer test may or may not result in license suspension or other sanctions. Laws still vary greatly by state. In some states, refusing a PBT is a misdemeanor that is punishable by a fine and/or up to 90 days in jail. Check with your state website regarding the policy in your state, or better yet, consult with a licensed attorney.
Again, as mentioned above, most individuals who are stopped because an officer suspects they are intoxicated will most likely be arrested. Anyone who refuses to take a PBT when they are stopped for a DUI should expect to be arrested, and taken to the police station for booking and even more testing.
Once an individual is taken to the police station and asked to use the more sophisticated breathalyzer tests at the station, refusal will almost certainly result in a driver’s license suspension or revocation. Nearly every state requires that an individual voluntarily submit to these breathalyzer tests, or face an automatic driver’s license suspension. Most of these machines use a different approach to measuring BAC, such as infrared spectroscopy, where an infrared light passes through a sample of the person’s breath, and the machine measures the amount of infrared radiation that passes through the breath, allowing it to very accurately measure a person’s BAC. While these machines also have certain requirements, and their results can be challenged in court, refusing to take a breathalyzer test at the police station will result in loss of driver’s license and being charged with a DUI.
In addition, some jurisdictions may get a warrant to draw blood from the person and test the level of alcohol in the person’s blood. When BAC is measured in this manner, it is much more difficult for attorneys to challenge the results.