Breathalyzers are sophisticated instruments designed to measure Blood Alcohol Content (BAC), which reflects the concentration of alcohol in the bloodstream. While it is highly improbable that eating pizza would lead to systemic intoxication, trace alcohol in food might temporarily affect the device. The potential for a fleeting positive result is less about the food itself and more about the mechanics of the testing process.
How Breathalyzers Measure Alcohol
A standard breathalyzer measures the concentration of ethanol vapor in a person’s exhaled breath, not the blood directly. The device estimates BAC by analyzing air from the deepest part of the lungs, known as alveolar air. Alcohol consumed by the body enters the bloodstream and travels to the lungs, where it is expelled through the alveoli. This measurement relies on a scientifically established ratio, typically 2,100:1, which correlates the concentration of alcohol in the breath to the concentration in the blood. Modern evidential breathalyzers use technologies like infrared spectroscopy or fuel cell sensors, assuming the air sample accurately reflects the body’s internal alcohol level.
The Role of Fermentation in Pizza Dough
The possibility of pizza causing a temporary positive reading traces back to the fundamental process of making the dough. Pizza dough is leavened using yeast, a microorganism that consumes sugars in the flour during anaerobic fermentation. This metabolic activity produces two main byproducts: carbon dioxide gas, which causes the dough to rise, and ethanol. When the pizza is baked in a high-heat oven, the vast majority of this trace alcohol evaporates, or is “burned off.” However, in rare instances, such as immediately after eating a very fresh, extremely yeasty, or undercooked crust, minuscule residual alcohol vapors may linger in the oral cavity.
The Effect of Trapped Mouth Alcohol
The primary reason food can interfere with a breath test is the phenomenon known as “mouth alcohol.” This occurs when highly concentrated alcohol vapor is present in the mouth, tongue, or mucous membranes, rather than being expelled from the lungs via the bloodstream. Sources like mouthwash, certain medications, or trace vapors from fermented food can create this localized concentration. When the breathalyzer samples this concentrated vapor, it misinterprets it as a significantly elevated BAC reading. This result is inaccurate because it reflects a localized oral condition, not systemic intoxication.
Distinguishing Between True and False Readings
Law enforcement agencies employ specific procedural safeguards to ensure that breathalyzer results are based on systemic intoxication and not on residual mouth alcohol. The most common safeguard is the mandatory observation period, which typically requires a waiting time of 15 to 20 minutes before administering the test. During this time, the subject is closely monitored to ensure they do not eat, drink, smoke, or regurgitate. This waiting period is sufficient to allow any concentrated mouth alcohol vapor, whether from a food like pizza or acid reflux, to fully dissipate from the oral cavity. If the subsequent breath sample still registers a reading above the legal limit, it reliably indicates the presence of alcohol in the deep lung air and a true reflection of the BAC.