Breathalyzer.net

The team at Breathalyzer.net answers your top questions about breathalyzers!

Email your questions about breathalyzers to email (at) breathalyzer.net, and we'll choose new questions to feature in this column and in upcoming email newsletters.


Also, be sure to check our Frequently Asked Questions for more common questions about breathalyzers.

Three tests are typically used to measure a person's blood alcohol concentration (BAC), and measuring a person’s BAC is the most commonly used metric of alcohol intoxication for legal or medical purposes.

Law enforcement may choose to conduct one, two or all three tests, depending on the situation and applicable state laws. In some cases, a person may choose which test they’d like performed. While police officers often conduct various field sobriety tests, these tests only measure your reflexes and abilities, not your BAC.

The three tests are detailed below, along with additional information about each.

Breathalyzer/Breath Test. This test measures the amount of alcohol in the lungs, and is the most common type of blood alcohol test performed by law enforcement. Because of the high alcohol content remaining in the mouth and the upper digestive system, the breath test may inaccurately read high if it’s given soon after your last drink. (This is why we tell you to wait 20 minutes after your last drink to conduct a test).

Blood Test. This test measures the amount of alcohol found in a person’s blood stream, and is considered the most accurate test. It requires a qualified medical professional to draw a sample of your blood for testing, and will also show any presence of drug use.

Urine Test. This test measures the amount alcohol in the urine, and is the least accurate and the least reliable of the three tests. Since test results are based on alcohol content in your excreted urine, there may be a greater amount of alcohol in your urine versus the amount of alcohol you actually have remaining in your system. Like the blood test, this test also measures the presence drugs as well as alcohol.

The answer is a surprising yes, and this is actually one of our most common customer questions. It’s very common for people, especially men, to drink one beer and register a 0.00 %BAC on a breathalyzer 30 or 60 minutes later.

How come? Your body processes alcohol as soon as you start drinking, so your body begins absorbing, processing, and then eliminating the alcohol you consumed immediately upon your first sip. That being said, if your %BAC were 0.08 and you were no longer drinking, your BAC one hour later would likely be close to 0.06 %BAC. The average adult male eliminates 0.015 ndash; 0.020 %BAC from his bloodstream every hour.

Similarly, one beer of standard alcohol concentration can raise the average adult male’s BAC 0.015 %BAC. However, if the beer’s alcohol is not absorbed into the bloodstream immediately and the %BAC is not tested immediately, the body has processed out some (or all) of that one beer’s alcohol by the time the %BAC is tested with a breathalyzer. It’s when people consume multiple drinks an hour that the BAC level really starts to go up.

For instance, if you drank the beer in 10 minutes and waited 30 minutes after testing, it’s very likely your BAC would be at or very close to zero. If you had a meal prior to the beer, or are above the average male weight, it’s even more likely that your true %BAC was at or close to 0.000 %BAC. And in many cases, a true 0.002 %BAC or below (a very, very slight level -- NOTE 0.002 not 0.02) will register 0.000 %BAC, which ensures that any alcohol in the environment, say, at a bar, doesn’t register a false positive for the test taker.

Since 2002, it has been illegal in all 50 U.S. states for those over the age of 21 to drive with a blood alcohol concentration (BAC) that is .08% or higher, and before 2002, the legal limit was .10%.

In addition, some states include a lesser charge, typically called "driving while impaired," with a target BAC of .05%. Also, drivers under 21 in the U.S commonly must adhere to lower legal limits, typically 0.01% to 0.05%.

But how do these limits compare with BAC limits in other countries – is the U.S. more or less lenient when in comes to driving under the influence of alcohol?

It turns out that most countries have far stricter BAC laws than the U.S., and there has been a downward trend in further decreasing the limits in an effort to curtail drinking and driving fatalities.

For some countries, laws are not standardized at the national level, but instead they vary by state or province, and they may also vary by the class of driver. For instance, the BAC limit is lower for new drivers, and/or professional drivers such as those that drive taxis and buses, and/or for those on motorbikes.

There are countries with a zero-tolerance policy and as such, it’s illegal to have any alcohol in the blood while driving in these countries. Armenia, Azerbaijan, the Czech Republic, Hungary, Jordan, Kyrgyzstan, and Romania, are just a few countries with this limit.

At the .02% BAC limit, you’ll find China, Estonia, Poland, Sweden and others, and countries with the .03% BAC limit include Serbia, Japan, and Uruguay.

A .05% BAC legal limit is the most common and found in most Western European countries among others. Argentina, Australia, Austria, Belgium, Finland, France, Germany, Greece, Hong Kong, Israel, Italy, South Africa, Spain, Switzerland, Thailand, Taiwan, Turkey, and others all have this legal limit.


Joining the U.S. with a 08% BAC legal limit are Malaysia, Mexico, New Zealand, Norway, Puerto Rico, Singapore, and the United Kingdom, among others.

Most people believe New Year's Eve is the U.S. holiday with the highest frequency of drunk driving fatalities, and it’s a good guess. However, according to the National Highway Traffic Safety Administration (NHTSA), in terms of a single holiday, Thanksgiving is when most alcohol-related fatalities occur. This is because the risk increases when drinking is combined with heavy traffic and long-distance car trips.

The National Highway Traffic Safety Administration (NHTSA) also describes the ‘100 Day of Summer,’ the period of time from Memorial Day to Labor Day, and especially around major holidays like July 4th, as one of the most dangerous and deadliest times of the year on the Nation’s highways. It’s a time when there’s a significant increase in alcohol-related traffic crashes and fatalities. In fact, Fourth of July weekend proves to be the deadliest of all when looking at total fatalities for a four-day weekend, and 40 percent of them are attributed to driving while under the influence of alcohol.

QUESTION: Is the presence of ‘alcohol on the breath’ a reliable sign of alcohol consumption and intoxication?

‘Alcohol on the breath’ is not a reliable sign because alcohol is actually odorless. When people detect ‘alcohol on the breath,’ it’s actually the odor of things commonly found in alcoholic beverages. For instance, the breath of a person who drinks a non-alcoholic beer and a beer containing alcohol will smell the same.

In a study to test whether estimates of alcohol on the breath were reliable (Moscowitz, H., Burns, M. & Ferguson, S. Police officers’ detection of breath odors from alcohol ingestion, Accident Analysis and Prevention, 1999), experienced police officers were asked to detect an alcohol odor from 14 subjects. The subjects were at blood alcohol concentrations (BACs) ranging from zero to 0.13, and odor detection was over a 4 hour period, and before and after the subjects consumed food.

The result: Odor strength estimates were unrelated to BAC levels and estimates of BAC level failed to rise above random guesses. The researchers concluded that estimates of alcohol on the breath cannot be relied upon.

Yes, it’s absolutely true. Costs for a first time DUI conviction are typically $10,000 and up. The costs further skyrocket if you hit something or hurt somebody – and with the latter, clearly the costs are not just monetary.

Costs vary depending on the state and situation, and typically include the following:

• Fines and court fees: $500-1,200
• Bail: $150-2,500
• Towing: $100-600
• Alcohol Education and Treatment: $300 and up
• Alcohol Evaluation: $200 and up
• Driving/Alcohol-Awareness School: $400 and up
• License Reinstatement Fee: $100-250
• Attorney Fees: $2,500-5,000 and up
• Auto Insurance Increase (3-5 years): $4500 and up
• Miscellaneous additional fees: $200

Once alcohol reaches the bloodstream, it is generally metabolized at the rate of .015 of blood alcohol concentration (BAC) every hour, which can be estimated as one average drink of alcohol per hour.

However, many factors influence this rate and these include gender, weight and body composition, the contents of the stomach (for instance, if a person has eaten before or during alcohol consumption) a person’s general health and even the efficiency of the liver.

A person cannot increase the rate at which their body metabolizes alcohol. While it’s commonly believed that drinking coffee, taking a cold shower or exercising can speed up the rate at which alcohol is metabolized by the body, the passage of time is the only factor affecting the rate. The only control a person has over their BAC is to increase it by drinking alcohol.

There are a number of techniques and substances that are thought to be able to "trick" a breathalyzer into giving a lower blood alcohol content reading. These include eating an onion or garlic, sucking on a copper penny and more. Below are some of the common myths and facts about trying to fool a breathalyzer.

Myth: Eating strong foods like onions, coffee grounds and breath mints. These substances often mask the odor of alcohol on a person’s breath, but it doesn't change the alcohol content in their system. When a person blows into a breathalyzer, the blood alcohol level of air in the deep lungs, not the mouth, is measured. It is this value that is then converted into the corresponding Blood Alcohol Content (%BAC) estimate.

Myth: Drinking mouthwash. Mouthwash may be able to slightly mask the smell of alcohol on your breath, but like any other strong substance, it won't lower a breathalyzer reading. In fact, mouthwash contains a small amount of alcohol that could potentially increase the amount of alcohol registered on the breathalyzer whether a person was drinking or not. The same goes for some breath sprays. On a related note, testing is most accurate if subjects have not consumed any substance 15 minutes prior to testing to ensure that there is no residual mouth alcohol.
See BACtrack Breathalyzers featured on the Dr. Phil Show to see actual tests conducted with these substances.

Myth: Place pennies or a battery in your mouth. Pennies supposedly produce a chemical reaction, although it’s thought possible because they are made of copper, when in fact, pennies are mostly zinc or steel and copper-coated now. Meanwhile, batteries supposedly create an electrical charge. These methods were proved to be ineffective at lowering a person’s blood alcohol content on a Mythbusters episode. The other issue with either of these methods would be the difficulty in by placing something in one’s mouth and removing it without a police officer noticing.
See BACtrack Breathalyzers featured on the Mythbusters episode dispelling breathalyzer myths.

Fact: While there are many myths that are assumed to help trick a breathalyzer, is there a tried and true method to decrease a BAC reading? Of course and it’s quite simple – play it safe and don't drink and drive.