After the police arrest a driver suspected of DUI, they may take them to the police station for a breathalyzer test. A breathalyzer calculates the amount of alcohol in a person’s system by detecting chemical reactions with alcohol in their breath. However, breathalyzer tests can suffer from various limitations that affect the reliability of test results. These limitations can significantly impact the outcome of a DUI prosecution.
How Breathalyzers Work
A breathalyzer test measures a person’s breath or blood alcohol concentration, expressed as a percentage of alcohol in their system. Police departments use breathalyzers to gauge a driver’s level of intoxication since DUI laws make it illegal to operate a vehicle with a BAC of 0.08 percent or more. As a person’s body absorbs alcohol into the bloodstream, alcohol can evaporate from blood as it passes through the lungs, causing detectable alcohol vapors on their breath. A breathalyzer measures the amount of alcohol in their breath by passing the breath through a solution of potassium dichromate. When alcohol contacts this solution, it causes a chemical reaction that the breathalyzer can measure to calculate BAC.
Limitations of Breathalyzer Tests
Some of the most common limitations of breathalyzers include:
- Accuracy and Calibration – A breathalyzer machine may suffer from limitations in accuracy due to design or manufacturing defects or lack of calibration by the police department.
- Time Sensitivity – Because breath alcohol levels can fluctuate after a person stops consuming alcohol, police officers must follow the strict testing protocols for a breathalyzer device, including timing rules for performing the test.
- Contamination – Residual alcohol in a person’s mouth can affect breathalyzer test results. An intoxicated driver may hurriedly swish mouthwash after getting pulled over to remove the smell of alcohol from their breath, but alcohol in the mouthwash can show up on a breathalyzer result.
- Health Conditions – An individual’s health conditions can also affect the reliability of breathalyzer test results. Common chronic health conditions like diabetes, acid reflux, and GERD can skew test results. A person may suffer from a rare condition like auto-brewery syndrome that can cause a positive breathalyzer test result without their having consumed alcohol.
- Environmental Factors – Exposure of testing equipment to adverse environmental conditions, such as extreme temperatures, chemicals, or fumes, can affect its accuracy.
Legal Implications of Limitations of Breathalyzers
The limitations of breathalyzer tests can significantly affect a DUI case. Defendants may highlight issues that can affect breathalyzer results, such as the lack of calibration of testing equipment, police officers’ failure to follow testing protocols, or health conditions that might skew results. Prosecutors must have the records needed to justify the validity and reliability of a breath test.
Contact a DUI Defense Attorney Today
If you face DUI charges in Pennsylvania, your defense strategy may involve highlighting the limitations of breathalyzer tests. An experienced DUI defense lawyer can prepare and present compelling arguments challenging the reliability of test results. Contact McCormick & Vilushis LLC today for a confidential consultation to discuss how our legal team can help you pursue a favorable resolution to your DUI charges.