How to Pass a Breathalyzer: Can a Penny Help?

There are a lot of urban legends about strategies to trick the breathalyzer into a lower blood alcohol content reading and sucking on a penny is just one of them. The theory is that holding a penny in your mouth (or sucking it, or chewing it, depending on the version of the urban legend) can produce a more favorable breathalyzer reading by basically interfering with your mouth's saliva composition.

Some sources say that the more pennies in the mouth, the better, although they must be discreetly discarded before the test. The zinc and copper of the penny (not to mention the grime it has accumulated while in circulation) supposedly neutralize or mask the actual level of alcohol by inducing a chemical reaction or coating the inside of the mouth.

Some people say the breathalyzer is fooled into giving a lower reading; others suggest the breathalyzer is so confused by this new information that it simply doesn't work.

So, you've been drinking alcohol, but not enough to be drunk. You're driving home when you encounter a row of field sobriety tests on the offramp. A police officer is ready to approach your vehicle. Should you shove a dollar's worth of pennies into your mouth to confuse the breath sample?

No. Regardless of how stealthily this trick is executed, it doesn't work. Its usefulness would rely on the breathalyzer device actually somehow measuring the alcohol in a way that it could be altered by other substances.

Breathalyzers provide an infrared light that changes in intensity based on how much alcohol is in the mouth. First, the breathalyzer's light passes through a sample of the person's breath, which will cause the intensity of the light to change. The change in the light can be used to calculate the amount of alcohol in the sample, and therefore, the person's drunkenness. It's complicated for a little machine, but it was developed specifically because it's hard, if not impossible, to fool.

The concept of tricking the breathalyzer test does have a basis in fact, though. Old breathalyzers worked in a way that's similar to how many people seem to assume they still work, by measuring a chemical reaction based on the alcohol in the breath. These results were easier to manipulate with pennies or other tricks.

Other strategies have been passed around through word of mouth in order to fake out a breathalyzer test. Below, we'll discuss some of the popular theories. But it's been at least a decade or so since any of these shenanigans worked.

If you're looking for other debunked ways to lower your breath alcohol content (BAC) reading, you're in luck! However, it's important to note that attempting to trick a breathalyzer could result in legal consequences.

Mouthwash or Breath Spray

Some believe that using mouthwash or breath spray just before taking a breathalyzer test can mask the alcohol or trick the device. Many mouthwashes and breath sprays contain alcohol, which can actually increase the BAC reading rather than decrease it. This method can backfire and lead to higher readings.

Eating Strong Foods or Using Breath Mints

The idea here is that eating foods with a strong odor or using breath mints will mask the smell of alcohol, leading the officer to believe you're not intoxicated, or somehow interfere with the machine's ability to detect alcohol. Breathalyzers measure alcohol levels, not the smell of your breath, so this method is ineffective.

Hyperventilating, Exercising, or Holding Your Breath

Some people think that hyperventilating, exercising just before a test, or holding your breath can lower BAC readings by changing the composition of the breath. While these actions might slightly alter the breath sample, they do not significantly affect the concentration of alcohol in your bloodstream.

Breathalyzers are designed to measure deep lung air, where alcohol concentration is most closely related to blood alcohol content.

Drinking Water or Eating Food to Dilute Alcohol

The theory is that consuming large amounts of water or eating food will dilute the alcohol in the system, leading to a lower BAC reading. While staying hydrated and eating can affect how your body absorbs alcohol, they do not significantly change the alcohol concentration in your breath by the time you're tested.

The breathalyzer measures alcohol content in the breath that comes from the lungs, not the stomach.

These urban legends offer no reliable way to fool a breathalyzer test. The best way to pass a breathalyzer test is to drink responsibly and ensure your BAC is below the legal limit before driving.

Law enforcement agencies and breathalyzer manufacturers have developed these devices to accurately measure a person's BAC, making it nearly impossible to trick the system with simple tricks or gimmicks.

This article was updated in conjunction with AI technology, then fact-checked and edited by a HowStuffWorks editor.