According to the National Highway Traffic Safety Administration (NHTSA), 2024 saw more than 13,000 people killed in alcohol-related crashes in the United States. These crashes could have been prevented. Breathalyzers are a well-known way to help stop these deadly incidents from happening. So, how does a breathalyzer work and are there car breathalyzers that can help people prevent these fatal accidents?
In this article, learn all about the breathalyzer test, as well as specialized car breathalyzers such as ignition interlock devices.
Let’s get started.
What is a Breathalyzer Test?
A breathalyzer test is a device used to estimate the blood alcohol concentration (BAC) in a person’s breath, providing an indication of their level of alcohol intoxication. The history of breathalyzers dates back to early chemical devices, with significant advancements made in 1954 when the Indiana State Police, through Robert Frank Borkenstein, invented and refined the modern breathalyzer.
Today, breathalyzers are used by law enforcement both at roadside stops and in police stations for accurate BAC measurement.
How Does a Breathalyzer Work?
Simply put, a breathalyzer works by analyzing a breath sample to detect the presence and amount of alcohol vapor, which correlates with the alcohol concentration in the bloodstream. Law enforcement officers commonly use breathalyzer tests during roadside stops to assess whether a driver is impaired by alcohol.
Breathalyzer Test for the Car
In addition to police-grade equipment, handheld devices are now available for personal use, offering convenient and portable options for individuals to monitor their own blood alcohol content.
Ignition interlock devices, more commonly known as car breathalyzers, have quickly become one of the most effective tools in preventing drunk driving.
Studies suggest that ignition interlock systems reduce repeat DUI offenses by about 70 percent. Many states have created laws requiring the installation of IIDs for even first-time DUI offenses. Let’s take a closer look at how a breathalyzer works in your car.
BAC limits and DUI laws may vary by state. This article is intended for informational purposes only and does not constitute legal or medical advice. Please consult local laws or a licensed professional for guidance.
What is an Ignition Interlock Device?
Ignition interlock devices are breath-test devices that connect directly to your car’s ignition system. A mouthpiece allows you to blow into the device, which measures your blood alcohol concentration. These devices perform breathalyzer tests to determine your breath alcohol content (BAC) before allowing the car to start. You have to blow into this mouthpiece every time you want to start your car.
If your BAC exceeds a set limit (usually 0.02 percent), the device will prevent you from starting your car for either a set period of time or until you provide a clean breath sample.
Even after your car has started and you are on the road, the ignition interlock device will require periodic breath samples, known as ignition rolling retests. These retests ensure that your initial breath sample came from you and not from a third-party. If your breath sample registers above the limit, the device will log the infraction and cause your car to set an alarm (blinking lights, honking horn) until you either provide a clean sample or pull off the road and shut off your engine.
Understanding Blood Alcohol Concentration (BAC)
Blood alcohol concentration is simply a measure of ethyl alcohol in your blood. It is expressed as a percentage that connotes the amount of alcohol (in grams) per 100 milliliters of blood. For example, a BAC of 0.08 percent means that you have 0.08 grams of alcohol for every 100 milliliters of blood in your system. While blood is the primary (and arguably best) means of measuring your BAC, it can also be determined through your breath and urine. A blood test is considered the most accurate method for determining your BAC level. Blood tests are often used as a confirmatory method when breathalyzer results are in question or require legal validation.
Your liver is responsible for breaking down alcohol in your system. It’s generally efficient at doing its job, metabolizing about one drink’s worth of alcohol in one hour. However, you are likely consuming more alcohol than your liver can break down at once. Any alcohol that your liver cannot immediately metabolize remains in your bloodstream and circulates throughout your body, contributing to an elevated BAC.
The Standard Drink
According to the National Institute on Alcohol Abuse and Alcoholism, a standard drink in the United States contains about 14 grams of pure ethyl alcohol. In terms of what you’re actually drinking, that is equivalent to:
- 12 ounces of a regular, non-light beer
- 8 to 9 ounces of malt liquor
- 5 ounces of wine
- 1.5 ounces of distilled spirits and liquor (vodka, gin, whiskey, rum)
Of course, even within each specific drink type, the amount of alcohol can vary, and customary serving sizes can vary depending on who’s pouring your drink. It’s also important to understand that not everyone processes alcohol at the same rate based on a huge range of factors, including age, gender, and body weight. The amount of alcohol consumed and the time elapsed after consuming alcohol can influence how much alcohol is detected by a breathalyzer. Breathalyzers are designed to detect alcohol in individuals who have consumed alcohol, and detection depends on how soon after consuming alcohol the test is performed.
How Does a Breathalyzer Work in Your Car?
Ignition interlock devices operate similarly to modern breathalyzer devices used by police officers, and it all starts with the small sacs in your lungs known as alveoli. When you drink alcohol, it doesn’t completely break down and metabolize in your body. In fact, it ends up fairly intact in your bloodstream (in the form of ethyl alcohol).
Alcohol generally has a high volatility, meaning that it easily evaporates given your body’s natural internal temperature. As your blood flows into and around your lungs, the alcohol in your bloodstream evaporates into the alveoli. With enough alcohol (in its gaseous vapor form) concentrated in your alveoli, a breathalyzer test can detect alcohol and measure alcohol in your breath to estimate your blood alcohol concentration (BAC) with every breath to a fairly accurate amount. The general estimate is that 2,100 milliliters of exhaled breath contain the same amount of alcohol as 1 milliliter of blood — a 2100:1 partition ratio used to convert breath alcohol to BAC.
How IIDs Operate & Measure BAC Levels
The modern ignition interlock device operates using complex fuel cell technology. Each fuel cell comprises two platinum electrodes surrounding a porous acid-electrolyte material. When you breathe into the device, your breath passes into one of the platinum electrodes at one side of the fuel cell. The platinum reacts with any alcohol in your breath, oxidizing it and producing protons, electrons, and acetic acid.
The electrons move through a wire from one platinum electrode to the other and to an electric current meter. The protons move and combine with the electrons and oxygen to create water, which further helps to conduct the electrical current. Essentially, the more alcohol that gets oxidized, the stronger the electrical current. A microprocessor measures the level of the electrical current and spits out the blood alcohol concentration.
Infrared spectroscopy breathalyzers are another highly accurate type of device used to measure alcohol in a person’s breath. These devices emit an infrared beam or infrared light through the breath sample. Alcohol molecules absorb specific wavelengths of the infrared light, and the device analyzes the absorption spectrum to determine the concentration of alcohol present. This technology is widely used in professional settings due to its precision. It’s important to note that breath temperature can influence the accuracy of breathalyzer readings, so proper calibration and consideration of physiological variables are necessary to ensure reliable results.
How Your Blood Alcohol Concentration Affects You
While it may seem like an arbitrary unit of measure, especially considering how people react differently to alcohol and being drunk, blood alcohol concentration can actually help accurately predict certain actions and behaviors and your general level of impairment.
Blood alcohol concentration is commonly used to assess alcohol intoxication and determine impairment levels for legal and safety purposes.
0.02 percent (about 2 drinks)
You will experience general relaxation, some slight body warmth, and an altered mood. This is also when you will begin to lose some of your judgment. You will also have trouble dividing your attention and your visual acuity, including your ability to track moving objects.
0.05 percent (about 3 drinks)
You will feel good and begin to let go of your inhibitions, causing your behaviors to become much more exaggerated. Your alertness will go down, and your judgment will be greatly impaired. You’ll have trouble with small muscle control and coordination.
0.08 percent (about 4 drinks)
At this point, you are legally drunk. Your judgment, memory, self-control, and memory will be heavily impaired, and you will have problems with your muscle coordination, including your general balance, vision, hearing, and speech. If you tried to get behind the wheel, you’d be unable to steer properly, control your speed, or process information quickly.
0.10 percent (about 5 drinks)
At this point, your reaction time and coordination will deteriorate immensely. You’ll slur your speech, you’ll have trouble with coordination, and your general thought processes will be much slower.
0.15 percent (about 7 drinks)
You’ll have extremely reduced muscle control and coordination, and you’ll experience a major loss of balance. If you tried to drive, you wouldn’t be able to pay attention to the actual process of driving, and you’ll have significant problems controlling the vehicle, which will only be compounded by impairments to necessary auditory and visual processing.
These estimates could vary based on numerous factors such as gender, height, weight and other considerations.
Prevent Drunk Driving with Low Cost Interlock
You are responsible for your own actions, whether or not you have an ignition interlock device installed.
If you plan to drink, make sure that you plan ahead. For example, you can plan to:
- Have a designated driver
- Use a rideshare or taxi service
- Space out your drinks or alternating between alcoholic and non-alcoholic drinks (this gives your liver enough time to break down the alcohol in your system to prevent high BAC levels)
Of course, there’s nothing wrong with staying away from alcohol altogether. You do not always need alcohol to have a good time.
Ignition interlock devices, enforcement of laws, and wider education go a long way, but preventing drunk driving also takes work at an individual level. For more information about affordable ignition interlock devices, contact our team at Low Cost Interlock today.