Do Mouthwashes Affect Breathalyzer Readings?

Mouthwash can occasionally affect breathalyzer readings due to its alcohol content. Many mouthwashes contain ethanol, a type of alcohol, which can persist in the mouth and be detected by breathalyzers, leading to false positive readings for blood alcohol concentration (BAC).

Alcohol Content in Mouthwashes

Most mouthwashes contain a certain percentage of alcohol, usually between 15-30%. This concentration can be sufficient to register on a breathalyzer, depending on the device used and the timing of the test.

How Breathalyzers Work

Breathalyzers measure the amount of alcohol in the breath, which is then correlated with the alcohol content in the bloodstream. If alcohol from mouthwash is present in the mouth, it can be exhaled and detected by the device. The breathalyzer works by analyzing the breath to estimate the BAC. Different models have varying sensitivities and methods for detecting alcohol, which can influence the results.

Timing and Effects of Mouthwash

The effect of mouthwash on breathalyzer results is generally temporary. If a person waits a period of time after using mouthwash before taking a breath test, the alcohol may dissipate enough to avoid affecting the reading significantly. In legal contexts, it is often advised to wait a certain amount of time (usually 15-30 minutes) after using mouthwash before taking a breathalyzer test to prevent misleading results.

A personal experiment with a portable breathalyzer a few years ago demonstrated this. After gargling with mouthwash, the portable device initially registered a BAC of around 0.3. However, after waiting fifteen minutes, the reading became barely detectable. Readings from alcohol in the bloodstream, on the other hand, are more stable and less influenced by temporary effects like mouthwash use.

Types of Breathalyzers

There are different types of breathalyzers in use. In the past, they used a “flame box” technique, where the breath would heat a flame, and the temperature of the flame indicated the alcohol concentration. However, this method was not very accurate and required skill to obtain reliable results.

Currently, Fuel Cell technology has replaced flame box devices and is considered much more accurate and portable. While this technology has greatly reduced the risks of false positives, one can still trigger a breathalyzer with mouthwash. The police are aware of this and continue to use more reliable devices for official tests.

It's important to note that even a BAC of 0.04 or 0.08 can result in charges of DUI (Driving Under the Influence) or DWI (Driving While Intoxicated). In legal terms, these charges can have severe consequences and can lead to fines, license suspension, and even imprisonment.

Therefore, it is crucial to be cautious with alcohol-containing products like mouthwash when facing a breathalyzer test, especially in legal or law enforcement contexts. Understanding the workings of breathalyzers and the temporary effects of mouthwash can help in making informed decisions when undergoing these tests.