Search for
Login | Username Password Forgot? | Email: | Create Account

Non English | Entries: 107 | Views: 5714 | Modified: 2 years ago | | Add to My Feeds
Beating the Breathalyzer
December 22nd, 2007


Traditional Breathalyzer

The breathalyzer (AKA breathalizer) is a device used by the authorities for measuring the blood alcohol content (BAC) of a person. This device was originally designed by Smith & Wesson and were once large machines that cost thousands of dollars per unit. Police departments were the only ones with these devices and they were base units at the station which required them to bring subjects back to the station to be tested.

Handheld Breathalyzer

Today hundreds of manufacturers make small, portable breathalyzer units that much more accurate and cost as little as $20 each. This enables law enforcement officers to give breathalyzer tests out in the field and the average person can easily purchase one of these units for their own person use.


In most states you are considered intoxicated if you drive while your BAC level is over 0.08%, however some states have the limit as high as 0.1%.

Look at the chart below, it only takes 3 drinks (units of alcohol) to make the average person too intoxicated to drive.

BAC Chart

For the average person it takes an hour to process one drink, so if you have 3 drinks putting you over the limit it will take approximately one hour to put you back into the 2 drink range and up to 3 hours to bring your BAC back down to 0.00%.

BAC Over Time

Alcohol effects different people in different ways. A person who drinks everyday may be able to function perfectly fine with a BAC of 0.1%, while another person of the exact same age, weight, size, and stomach composition who rarely drinks might be falling all over the place with a BAC of 0.1%. Your BAC level has absolutely nothing to do with your tolerance of alcohol. The BAC level was set to account for the average person, not the person with an insanely high tolerance who drinks a case a night and two on the weekends. So many people are totally shocked to realize how high their BAC is after just a few drinks.


Many people believe that they can beat the breathalyzer test by sucking on breath mints, onions, a penny, or using mouthwash. However, these are all myths.

Myth Busters

An episode of the Discovery Channel’s MythBusters tested substances usually recommended in this practice—including breath mints, mouthwash, and onion—and found them to be ineffective. Adding an odor to mask the smell of alcohol might fool a person, but does not change the actual alcohol concentration in the body or on the breath which is what is measured by the breathalyzer. 

Alcohols Effect on the Body

You must blow hard to get an accurate reading from a breathalyzer and this test actually measures the alcohol from air exhaled from deep within the lungs and not just from your mouth. When you drink alcohol the mouth, throat, stomach, and intestines absorb alcohol into the bloodstream. When yout blood passes through the lungs’ air sacs, the alcohol moves across them as well, thus the concentration of alcohol in the breath is directly proportional to the concentration of it in the blood. The breath alcohol to blood alcohol ratio is 2,100:1. This means that every 1 ml of blood has the same amount of alcohol in it as 2,100 ml of exhaled breath.

Activated CharcoalActivated Charcoal Tablet

Interestingly, substances that might actually reduce the BAC reading were not tested on the show. These include a bag of activated charcoal concealed in the mouth (to absorb alcohol vapor), an oxidizing gas (such as N2O, Cl2, O3, etc.) which would fool a fuel cell type detector, or an organic interferent to fool an infra-red absorption detector. The infra-red absorption detector is especially vulnerable to countermeasures, since it only makes measurements at particular discrete wavelengths rather than producing a continuous absorption spectrum as a laboratory instrument would do.

We used the Alcohawk Pro Digital Breathalyzer which has a ±0.002% accuracy to do our own tests and measure the BAC of a person before and after putting a teabag filled with activated charcoal tablets in their mouth:

John had a BAC of 0.12% BAC and the bag of activated charcoal effectively lowered his BAC to 0.08%.
Natalie had a BAC of 0.14% BAC and the bag of activated charcoal effectively lowered her BAC to 0.09%.

We found that this method only slightly lowers the BAC of the person taking the test and requires that a person essentially breathe through a teabag containing charcoal tablets. If the police officer giving the test uses the proper procedures then he will check the inside of the persons mouth to make sure they are not concealing anything in their mouth which may effect the test results.

On the other hand, products such as mouthwash or breath spray can “fool” breath machines by significantly raising test results. Listerine, for example, contains 27% alcohol; because the breath machine will assume the alcohol is coming from alcohol in the blood diffusing into the lung rather than directly from the mouth, it will apply a “partition ratio” of 2100:1 in computing blood alcohol concentration—resulting in a false high test reading. To counter this, officers are not supposed to administer a PBT for 15 minutes after the subject eats, vomits, or puts anything in their mouth.

Vary Your Breathing Pattern

The tests we ran found that varying our breathing patterns had a small effect on the readings:

Holding your breath for 30 seconds before exhaling increased the blood-alcohol concentration (BAC) from 0.12% BAC to 0.15% BAC.
Hyperventilating for 20 seconds immediately before, on the other hand, decreased the blood-alcohol level by from 0.12% BAC to 0.10% BAC.
Keeping the mouth closed for five minutes and using shallow nasal breathing resulted in increasing the BAC from 0.12% to 0.15%, and testing after a slow, 20-second exhalation increased levels by 0.02%.

We found two sources online, “How Breathing Techniques Can Influence the Results of Breath-Alcohol Analyses”, 22(4) Medical Science and the Law 275 and “Accurate Measurement of Blood Alcohol Concentration with Isothermal Breathing”, 51(1) Journal of Studies on Alcohol had similar findings to our own.

Dr. Michael Hlastala, Professor of Physiology, Biophysics and Medicine at the University of Washington has gone farther and concluded:

“By far, the most overlooked error in breath testing for alcohol is the pattern of breathing….The concentration of alcohol changes considerably during the breath…The first part of the breath, after discarding the dead space, has an alcohol concentration much lower than the equivalent BAC. Whereas, the last part of the breath has an alcohol concentration that is much higher than the equivalent BAC. The last part of the breath can be over 50% above the alcohol level….Thus, a breath tester reading of 0.14% taken from the last part of the breath.

Breathalyzer Police

Many police officers know this. They also know that if the machine contradicts their judgement that the person they arrested is intoxicated, they won’t look good. So when they tell the arrestee to blow into the machine’s mouthpiece, they’ll yell at him, “Keep breathing! Breathe harder! Harder!” As Professor Hlastala has found, this ensures that the breath captured by the machine will be from the bottom of the lungs, near the alveolar sacs, which will be richest in alcohol. With the higher alcohol concentration, the machine will give a higher — but inaccurate — reading.

Pulling the Trigger


We found that a person with a BAC level of 0.12% BAC could significantly lower their BAC level if they stop drinking. Drink water and then induce vomitting. After clearing their stomach they then ate food to further absorb any remaining alcohol in their body and took a brisk 10 minute walk as their body began metabolizing the food. We measured their BAC again after this process (20 minutes after the first reading) and found that their BAC was only 0.07%. This lowered the level significantly faster than just time alone which would take approximately 1.5 hours to reach this level according to the graph above.


Alcohawk Pro Kit

AlcoHawk Pro is FDA/DOT/NHSTA approved Professional Grade breathalyzer. The AlcoHawk Pro takes a deeper breath sample from the user and provides more accurate results than similar models, FlowCheck Technology ensures enough air is blown into the machine.

The Professional Grade Alcohol Breathalyzer The Alcohawk Pro is a extremely accurate semiconductor-oxide breathalyzer. This professional model takes a deeper breath sample from the user and provides more accurate results than similar models. A deeper breath sample will draw the air out of the bottom of the lungs, and into the AlcoHawk Pro to determine the users BAC. By ensuring that the user is getting that deep lung air, you will be assured that the AlcoHawk will provide you with the most accurate results available. This Professional Grade Breathalyzer is Perfect for many professional organizations for employee screening, emergency room care, hospitals, schools, law enforcement, and roadside testing.

The semiconductor sensor accuracy is ±0.002% BAC at 0.10% BAC and is DOT / NHTSA cleared. The Alcohawk Pro is also 510(k) Certified by the U.S. FDA.

 Breathalyzer Phone

LG Korea has even introduced a breathalyzer phone, the LG LP4100 which has a built-in breathalyzer capabilities that records your blood-alcohol level. When blown into by an intoxicated person, it will gives a warning and displays a nifty little animation of a car swerving on a road and crashing into traffic cones.


There is no effective way to significantly lower your BAC level. You can use activated charcoal tablets to slightly lower the level by 0.04-0.05%, however if you are completely intoxicated then this will not be a significant drop. Also, law enforcement will most definitely be aware of the fact that you have something in your mouth that could effect their test results.

Car CrashLohan Crash

I do not recommend drinking and driving as it kills thousands of people each year. Get a designated driver, stay over night, call someone, get public transportation and pick up your car the next morning.

Matthew Spencer recently killed his entire family while driving intoxicated.

The biggest risk of driving intoxicated is not getting arrested, it’s getting killed, killing someone else or even worse:

Not Everyone Dies From Drunk Driving

More from

^ Back To Top