How Long Does Alcohol Stay in Your System for a Breathalyzer?

Breathalyzers & Drunk Driving

In the United States, drunk driving leads to the death of over 10,000 people a year.¹ This death toll includes those who were driving intoxicated and innocent people who were in the wrong place at the wrong time. These events leave children without parents, parents without children, brothers without sisters, and so on. Drunk driving is one of the many ways that alcohol destroys families and has caused an irreparable amount of damage to the lives of so many.

In order to try and lower the number of drunk driving accidents, police officers started using breathalyzers to detect alcohol in suspected drunk drivers. They also look for signs like smelling alcohol on their breath, slurred speech, and the ability to walk in a straight line. Field sobriety tests paired with breathalyzers are crucial to keep the streets safe from drunk drivers.

How Does a Breathalyzer Work?

When someone is drinking, the alcohol enters the bloodstream and passes through the lungs. A breathalyzer takes the alcohol vapors in the breath to determine the blood alcohol concentration. Someone simply must blow into the breathalyzer, and the machine will output a number determining the person’s blood alcohol concentration (BAC) and whether they are fit to drive. In the United States, a blood alcohol concentration of 0.08 makes someone too impaired to legally drive and could get them in serious trouble with the law, especially if this is not their first offense.

While breathalyzers are usually an effective means of determining someone’s level of intoxication, they are not always an exact science. With this said, exactly how long does alcohol stay in your system for a breathalyzer test?

How Long Does a Breathalyzer Detect Alcohol?

Because alcohol metabolism is different for everyone, there is no single answer as to how long a breathalyzer can detect alcohol in a person’s system. In general, a breathalyzer can first detect alcohol in a person’s system about 15 minutes after it has been consumed and up to 24 hours later.²

If you want to stay under a BAC of 0.08, the general rule is that you should not drink more than one standard drink an hour, but this rule comes with many catches. Generally, alcohol is metabolized at an average rate of 15 to 25 milligrams every hour,² but because everyone is different, the same number of drinks can lead to drastic discrepancies from one person’s blood alcohol concentration to another.

Along with the amount of alcohol consumed and the timeframe in which it was consumed, body weight, age, gender, medications, stomach contents, alcohol tolerance, and liver health can all affect a person’s BAC and breathalyzer numbers. Along with the numerous factors that can impact a person’s BAC, like all machines, breathalyzers also come with a margin of error. Some lawyers argue that this margin of error is as high as .01 percentage point.³

If you have anything to drink, it is safer to skip driving and call an Uber or walk instead. Not only could you save yourself the legal headache, but also you could save your life or the life of someone else. If you are trying to determine how to beat a breathalyzer, or you have already gotten a DWI (driving while intoxicated) or DUI (driving under the influence), it may be time to take a long look in the mirror. Our rehab in Massachusetts offers alcohol recovery programs that help people reevaluate their relationship with drinking so that they can move on with their lives alcohol-free.

Patients at our Wilmington rehab center also have access to different care levels, like partial hospitalization or intensive outpatient programs to ensure they get the most appropriate care for their needs.