How Accurate Are Breathalyzer Tests?

How Accurate Are Breathalyzer Tests?

In the US, drunk driving is a frequent occurrence. To reduce that frequency, law enforcement takes the crime very seriously. They employ checkpoints and keep a vigilant eye for those who may be driving under the influence. With the help of breathalyzer tests, police officers make many DUI arrests. But are breathalyzers an accurate way to determine impairment?

The Value of the BAC

The blood alcohol content, or BAC, is a value that determines whether a driver is over the legal limit for alcohol. Although there are three types of BAC test, breathalyzer tests are the most common. Blood tests are the most accurate, but they aren’t the most convenient. In the field, an officer cannot safely administer a blood test. It needs to be done in a clinical environment with a needle. Another option is a urine test. However, that test is also invasive.

The remaining BAC test is a breathalyzer. Due to their small size, breathalyzers give police officers a portable option. Officers can carry them in the field. Then, they can easily administer the test. With a breathalyzer, an officer can get an immediate BAC reading and use that reading to determine if she should make an arrest.

Although breathalyzer tests do give officers a BAC reading, the results of them aren’t accurate. The breathalyzer gives an officer probable cause to make an arrest. However, it does not provide evidence that a prosecutor can use in court. Often, lawyers dispute the results of breathalyzer tests. When they do, they may be able to get the charges against their clients dropped.

The Technology Behind Breathalyzer Tests

To understand the flaws of breathalyzers, you need to understand the technology behind them. There are two main types of breathalyzers. First, there are ones with semiconductor sensors. Second, you have the breathalyzers with platinum fuel cell sensors. Semiconductor breathalyzers use a cheaper material than fuel cell senor breathalyzers. However, that material is less reliable. As a result, semiconductor breathalyzers are less accurate.

False Positives

When someone tests for BAC with a semiconductor sensor test, he is likely to get false positives. Ketones, which occur naturally in your blood, are similar to the chemicals in alcohol. The breathalyzer could mistake ketones for alcohol and provide a high BAC. However, you might not have much alcohol in your system. The false positive is enough for the officer to make an arrest, although you might be innocent.

It’s important to note that most police officers do not have breathalyzers that use semiconductor technology. Instead, they use the more reliable fuel cell sensors. They offer more accurate readings and fewer false positives. With this technology, breathalyzers can tell the difference between ketones and alcohol.

Factors that Impact Breathalyzer Tests

Despite being more accurate than semiconductor technology, fuel cell sensor technology has its flaws. Here are a few common factors that affect the breathalyzer:

  1. Foreign Matter – If you have any foreign matter in your mouth, your breathalyzer can deliver a false positive. There is good reason for this. Any foreign matter (like food) in your mouth could have absorbed alcohol. Toothache medicines, mouthwash, and breath mints can all contain alcohol. When you blow into the device, it will register the alcohol vapor from the food. Your mouthwash could be enough for an officer to arrest you for suspicion of a DUI.
  2. Calibration – One of the important keys to maintaining a breathalyzer is calibration. After some time, breathalyzers can give inaccurate readings. If an officer fails to calibrate his machine, then the results of your breathalyzer could be inaccurate.
  3. Software errors – Breathalyzers rely on software to provide readings. Without working software, breathalyzers don’t work. When there’s a bug or glitch in the software, a breathalyzer can provide inaccurate results.
  4. Human Error – No one is perfect, including law enforcement. When a police officer administers the breathalyzer test, he could make a mistake. If that occurs, the results could be incorrect.
  5. Lack of repeat tests – For the most accuracy, a police officer should administer the breathalyzer several times. Breathalyzer tests that use fuel cell technology work best when there are multiple tests. However, officers often only administer the test once. This provides less-than-ideal results
  6. The Environment – The outdoor environment can affect your breathalyzer’s results. If there are any paint fumes, varnish fumes, or chemical fumes, the test could provide false results.

Are Breathalyzers Accurate?

While breathalyzers can be accurate, they are not always accurate. With so many factors that can provide false results, breathalyzers leave a lot of room for mistakes. It’s not uncommon for someone to face DUI charges for an inaccurate breathalyzer. Fortunately, a lawyer may be able to help you fight the charges. If he can prove that the breathalyzer was inaccurate, then he shows that the officer had no grounds for an arrest. A breathalyzer refusal lawyer can help you fight unfair DUI charges.