Frequently Asked Questions (FAQs)

Breathalyzer FAQs

Top Four Frequently Asked Questions

1. Why do I need a breath alcohol tester?

A Breathalyzer is a valuable purchase to ensure personal safety and the safety of others. An individual may purchase one for self-testing and monitoring to avoid the consequences of driving while intoxicated, or simply for a general understanding of how alcohol affects the body.

Since factors like weight, muscle mass, and recently consumed food or beverages all affect the measurement of person's blood alcohol content (BAC), it's impossible to accurately gauge intoxication level without a measurement tool like a breathalyzer. People are often enlightened when they measure their %BAC, particularly on different occasions after the same amount of alcohol is consumed.

2. What is the difference between the Personal and Professional Breathalyzer models you offer? Is a Professional Breathalyzer worth the extra money?

All breathalyzers sold at are high quality and accurate products, and meet the standards of FDA 510(k) cleared devices, which means that the product has been deemed "safe and effective" for consumer use.

We've simplified the process of selecting a breathalyzer by categorizing all models into one of two categories: Personal Breathalyzers, which use semiconductor oxide sensors, and Professional Breathalyzers, such as BACtrack Mobile, BACtrack S80,BACtrack Trace, BACtrack S75, BACtrack Element, and Lifeloc FC-10, which use fuel cell sensors.

Professional Breathalyzers (which utilize fuel cell sensors) provide the following benefits over Personal Breathalyzers (which utilize semiconductor sensors):
  • They will not show a false positive for someone who is diabetic or on a low calorie diet. Semiconductor models will sometimes show a false positive result for these individuals. 
  • They provide more accurate and more consistent results as compared with semi-conductor models. For example, you are more likely to show the same test result when you test someone repeatedly in a very short period of time. In addition, they are more accurate at higher BAC concentrations, compared to semiconductor models, which often lose accuracy at higher BAC values. 
  • They can remain accurate for up to thousands of tests.
  • They provide more precise readings since %BAC readings are displayed to the thousandth decimal place (0.054%) versus to the hundredth decimal place (0.05%).
Breathalyzers that utilize fuel cell sensors typically sell for over $450; however, this technology is becoming more affordable with models like the BACtrack S80BACtrack Mobile, BACtrack Trace, and BACtrack Element,, which are available for under $150.

3. Which breathalyzer model is right for me?

If you are interested in getting the highest level of accuracy in your readings, our recommendation is to spend the extra money on a Professional level breathalyzer that uses fuel cell sensor technology. These breathalyzers offer the same advanced technology used by law enforcement for preliminary screenings for a fraction of what they have previously cost. Law enforcement, substance abuse centers, clinics and businesses typically purchase these models, although they are often purchased for individual use too.

If you are more concerned with alcohol detection, the presence of alcohol versus the precise measurement of %BAC, a semiconductor oxide unit is likely satisfactory for your needs. These models are often used for self-testing or testing friends and family. The quality of these breathalyzers is far above novelty grade breathalyzers and they are both affordable and accurate.

4. What factors are important in choosing a breathalyzer?

Accuracy is likely the most important factor when making a breathalyzer purchase, so you should consider the Sensor Type – Semiconductor versus Fuel Cell. See question #3 above for information about the differences between these sensor types. Essentially, both options will provide accurate readings and the degree of accuracy will increase with the price.

FDA Approval is another important requirement to consider when choosing a breathalyzer. Every personal breathalyzer sold through meets the standards of a FDA 510(k) cleared device, which means the product has been deemed "safe and effective" for consumer use.

Breath Sample Collection is an essential factor, and critical to an accurate breathalyzer reading. While the use of mouthpieces is one element that aids in obtaining breath samples that exclude external air, other aids to accuracy are found in the actual product design. For instance, the miniature air pump featured in the BACtrack Mobile Breathalyzer, BACtrack S80, BACtrack Trace, and BACtrack Element allows for the highest level of precision in collecting a breath sample. During use, the user can actually feel the "click" of the pump collecting the breath sample.

Lastly, you should look at the Brand of Breathalyzer you are purchasing. The manufacturer should be reputable, in the business of selling breathalyzers, specifically, for an extended period of time and have the endorsement of professionals and press as a result of providing a quality and accurate product.

General Breathalyzer Questions

Common questions about Breathalyzers are listed below. If you don't see an answer to your question, please feel free to contact us at or 1-877-334-6876

How does a breathalyzer work? What types of technology do they employ?

Most breathalyzers use one of three technologies to detect Blood Alcohol Content or Blood Alcohol Concentration (BAC), which is the concentration of alcohol in a person's blood: a semiconductor oxide sensor, a fuel cell sensor or a spectrophotometer, the latter being the technology used in large, table-top breathalyzers often found at police stations. offers breathalyzers with semiconductor oxide sensors and fuel-cell sensors.

Semiconductor oxide-based testers, such as the BACtrack S70, BACtrack S50 and the new BACtrack keychain breathalyzer are relatively new and very affordable. An ethanol-specific sensor is used to measure the subject's BAC. Semiconductor oxide sensors offer many benefits, including low cost, low power consumption and small size.

Semiconductor oxide based testers require calibration service on a more frequent basis (every 300-400 tests or once a year) than fuel cell based testers (every 1,000 tests or once a year). When used for personal, home and low-volume professional testing, semiconductor oxide models have been proven to perform very well and provide accurate readings.

Fuel cell testers, such as the Lifeloc FC-10 Series, BACtrack Mobile, BACtrack S80 Pro,BACtrack Trace, and BACtrack Element, offer extremely high accuracy and sensitivity, in addition to being handheld and portable. In over 30 US states, roadside evidential testing is now permitted using testers using fuel cells. A fuel cell measures alcohol content by creating a chemical reaction that oxidizes the alcohol in the sample and produces an electrical current. The more alcohol that is oxidized, the greater the current. The current is measured to determine the subject's BAC.

Spectrophotometer technology is used in large, table-top breathalyzers often found at police stations. Spectrophotometers work by identifying molecules based on the way they absorb infrared light. The level of ethanol in a sample is singled out and measured, and a subject's alcohol level can then be determined. does not carry spectrophotometer testers.

What is %BAC?

Blood Alcohol Content or Blood Alcohol Concentration, abbreviated BAC, is the concentration of alcohol in a person's blood. BAC is most commonly used as a metric of intoxication for legal or medical purposes, and it's usually measured as mass per volume. For example, a BAC of 0.05% means 0.05 grams of alcohol per 100 grams of a person's blood, or 0.5 grams of alcohol per 1000 grams of blood.

Factors that affect your BAC include the following:
  • Age – As you age, the intoxicating effects of alcohol become increasingly pronounced.
  • Gender – Alcohol is highly water soluble. Because women generally have lower water content in their bodies than men, they usually reach a higher BAC if they consume alcohol at a similar rate to their male counterparts, even if they are the same age and weight. Women also have a lower quantity of an enzyme in their stomachs that breaks down alcohol than men.
  • Rate of Consumption – The faster you consume alcohol, the faster your BAC will rise.
  • Drink Strength – The more alcohol a drink contains, the more will end up in your bloodstream.
  • Body Type – The more you weigh, the more water you tend have in your body, which has a diluting effect on the alcohol you consume. That’s why larger people usually require more drinks to “keep pace” with their smaller companions.
  • Fat/Muscle Content – Fatty tissue is low in water content and cannot absorb alcohol, and the alcohol must remain in the bloodstream until the liver can break it down. However, tissues that are higher in water content, such as muscle, do absorb alcohol. Hence BAC will usually be higher in the person with more body fat.
  • Metabolism – “Metabolic tolerance” varies from person to person and describes the rate at which alcohol is processed by the body.
  • Emotional State – Stress can cause your body to divert blood from your stomach and small intestines to your muscles, and slow down the rate of absorption of alcohol into your bloodstream. When you calm down and your blood flows normally again, you may experience a surge in your BAC.
  • Medications – Many medications react negatively with alcohol, including cold or allergy pills and prescription drugs. They can intensify the effects of alcohol and even endanger your health. If you are taking meds, check the product labels for alcohol warnings, or consult your doctor or pharmacist before you drink.
  • Food – If you drink alcohol on an empty stomach, your BAC will be higher than a person who has eaten before drinking. Food slows the absorption in your bloodstream by keeping the alcohol you consume in your stomach and for a longer period of time.
  • Carbonation – Carbonated drinks such as sparkling wine or champagne, or mixed drinks with sodas may increase the rate at which alcohol passes through your stomach and result in a higher BAC.
  • Diabetes – Alcohol can affect the glucose levels of people who have diabetes and cause hypoglycemia. Diabetics should consult their doctors about drinking alcohol and avoid drinking on an empty stomach.
  • Alcohol Intolerance – Alcohol may cause adverse reactions in some, including flushing of the skin, nasal congestion, elevated heart rate, and reduced blood pressure. According to the Mayo Clinic, alcohol intolerance is caused by a “genetic condition in which the body is unable to break down alcohol.
Am I safe to drive if my breathalyzer shows that I'm under the legal limit?

Absolutely not. Breathalyzers are for informational purposes only and there is no acceptable level of alcohol consumption that makes it safe to drive. Any alcohol that enters a person's body can impair reflexes, motor skills, and cognitive abilities.

Is a person's blood alcohol concentration (BAC) the only factor in determining whether or not a DUI is given?

No, the %BAC is not the only factor considered. Many people do not realize they can be charged with driving under the influence (DUI) or driving while intoxicated (DWI) even if their %BAC is under the legal limit. A person can be charged if they are at or over the "legal limit," which is .08 %BAC in all 50 US States, or if they are "impaired to any degree," regardless of the %BAC level.

Who invented the breathalyzer?

Though technologies for detecting alcohol vary, it's widely accepted that Dr. Robert Borkenstein (1912-2002), a captain with the Indiana State Police and later a professor at the University of Indiana, is regarded as the first to create a device that measures a subject's alcohol level based on a breath sample. In 1954, Borkenstein invented his breathalyzer, that used chemical oxidation and photometry to determine alcohol concentration. The invention of the breathalyzer provided law enforcement with a non-invasive test with immediate result reporting that can be used to determine an individual's level of intoxication.

Is there any way to trick a breathalyzer?
This is a very popular question! Read our research on the topic to see how specific substances may affect the accuracy of a breathalyzer reading in our Breathalyzer Question of the Month section. While you're there, read other interesting facts about breathalyzers, BAC, alcohol consumption, and more.

Is a breathalyzer eligible for my Flexible Spending Account (FSA) program?
Yes, in many cases they are eligible, however it really comes down to the FSA provider's individual policy. Please check with your FSA provider for further details.

Breathalyzer Usage and Maintenance

How do I use my breath alcohol tester?

For most models, a user simply blows through the mouthpiece for 5 seconds. The blowing is similar to blowing out a candle and the user should blow evenly for the entire 5 seconds. The breathalyzer will indicate when to start and stop blowing, and if the sample was not adequate for an accurate reading.

The sensors measure the alcohol level of air in the deep lungs. This value is converted into the corresponding Blood Alcohol Content (%BAC) estimate. Testing is most accurate if subjects have not consumed food or alcohol 15 minutes prior to testing to ensure that there is no residual mouth alcohol.

Why must I wait 15 to 20 minutes after consuming food or alcohol to ensure testing results are accurate?

A breathalyzer is able to calculate this percentage using only a breath sample because of the precise relationship between alcohol in the blood and alcohol metabolized into the lungs from the bloodstream. As such, it is important to make sure the mouth is clear of contaminant (including alcohol) so that the breath sample contains pure lung air, or as close as possible.

What type of maintenance is required to maintain a personal or professional breathalyzer? Do they require calibration?

Over time, all alcohol testers need to be re-calibrated to maintain accuracy. Calibration is a process of checking and adjusting the accuracy of a unit by comparing its results with a known value. For example, a known 0.080 %BAC gas concentration is blown into a breathalyzer, and the unit is adjusted to make sure it correctly reads 0.080 %BAC.

This process is sort of like winding a clock. When the clock is first set it displays accurate time. However, over time the clock gradually drifts a few minutes, and eventually can be off by quite a bit if you do not occasionally reset the clock. When selecting an alcohol tester, it is imperative to select a unit that is capable of being calibrated.

How often should I calibrate my breathalyzer to ensure accuracy?

We recommend re-calibrating breathalyzers with semi-conductor sensors every 300 tests or once a year, whichever one comes first. Breathalyzers with fuel cell sensors will remain accurate for thousands of tests, but should still be re-calibrated annually. Additionally for these models, using the breathalyzer regularly can actually help keep it accurate, as the moisture in exhaled human breath is beneficial to the sensor.

How do I get my breathalyzer calibrated?

See our Calibration FAQs for more information and to complete a form to send your breathalyzer to us for calibration. Our trained technicians will perform a full diagnostic check on all aspects of your breathalyzer as part of the calibration process.

Breathalyzer Accessories

How can I order additional mouthpieces for my breathalyzer? Do I need to replace the mouthpiece after every test?

Please visit our Breathalyzer Mouthpieces page to order mouthpieces and other supplies.

Replacing the mouthpiece after each test is optional if you are testing yourself. For professional testing and screening, it is recommended to change the mouthpiece after each test for safety and performance reasons.

How do I insert a mouthpiece into the breathalyzer?

The mouthpiece should insert easily into the mouthpiece, using the end with the larger inner diameter. It should be inserted approximately 1/8th inch.

How do I clean the mouthpieces if I plan to re-use them?

Clean them with warm soapy water and rinse, or wash them in a dishwasher.

Do you offer Disposable Breath Alcohol Testers?

Yes, we offer the BACtrack SingleShot. It's a disposable, single-use breath alcohol tester available in three %BAC thresholds: 0.02, 0.05 and 0.08. The BACtrack SingleShot is based on indicator chemistry that changes color in the presence of breath that contains alcohol.

A user will activate the small tube tester, blow through the SingleShot, and the crystals will indicate a positive or negative result based on the Blood Alcohol Content (BAC). For example, the SingleShot .02% will indicate "positive" by changing color when the user's alcohol level is at or above 0.02 %BAC. These units are accurate, inexpensive, and extremely small, which makes them easy to carry in a pocket.

Questions About Purchasing from

Why should I buy from is your trusted source for all types of breath alcohol detectors. We work directly with breathalyzer manufacturers to ensure quality products and service for our customers. Unlike other companies that may sell a variety of different products, we specialize in personal and professional breath alcohol testers. We're an industry leader and have been providing satisfied customers with alcohol testing equipment since 2001.

Our website features advanced 128-bit security, so you know your transaction is safe. Our advanced order fulfillment system ensures that most orders ship the same business day as long as the order is placed by 12:00 pm PST! Not many websites can offer that type of service. also offers free phone support to all customers. Our knowledgeable employees are here to answer any questions and address any concerns you may have. For toll-free phone support, please call us at 1-877-334-6876. Our normal hours of business are Monday through Friday, 9:00 am - 6:00 pm Pacific time.

How do I contact

For toll-free phone support, please call us at 1-877-334-6876. Our normal hours of business are Monday through Friday, 9:00 am - 6:00 pm Pacific time. Please refer to ourinfo page for additional contact information.

Does have a trade-in program if I'd like to upgrade my breathalyzer? recently launched the first-of-its-kind Trade-In and Save Program! The program allows customers to trade in their used breathalyzer to upgrade to the latest technology, and get a generous discount on their purchase of a new BACtrack breathalyzer. Learn more about the Trade-In and Save Program.

What is's Privacy Policy?

Please refer to our Privacy Policy page.

What else should I know about is a division of KHN Solutions LLC, a privately held company located in San Francisco, California. We believe that portable breath testers can help discourage drinking and driving and unsafe levels of alcohol consumption, and also serve as educational and entertaining safety devices.

How will the charge look on my credit card statement? 

After making purchase from, your statement will attribute the charge to "KHN Solutions," the name of our parent company.

Shipping, Refunds, and Returns

How long does it take for my order to arrive?

Breathalyzer orders placed by 12pm PST will ship the same business day, and all orders delivered within the Continental U.S. are currently shipped FREE via three to five day USPS Shipping. For higher valued orders, we may ship your order using UPS ground service to provide additional insurance. If you need a delivery by a specific date including next day shipping, please choose one of the UPS shipping options from the drop down bar during checkout.

Please allow additional transit time for during weekends and holidays and to some rural areas. Also, please note that UPS next day air and 2nd day air orders will not be delivered on weekends. UPS only delivers orders on regular business days. (Monday - Friday)

What shipping carriers does use?

All breathalyzers are shipped via USPS Mail. For higher valued orders (two or more Professional grade units) or orders over certain size/weight thresholds, we may ship your order using UPS Ground service to provide additional insurance.

International orders are shipped Global Priority Mail unless otherwise requested by the customer.

I live outside the United States. Does ship international orders? How much will it cost?

Yes. ships to most countries around the world. There are additional charges for international orders which will be displayed at time of checkout. Orders will take longer to reach destinations outside the United States.

Costs for shipping outside the USA are as follows:
  • Shipping to Canada: $30 on top of the cost of your order.
  • Shipping to anywhere else in the world outside US and Canada: $40 on top of the cost of your order.
My order arrived damaged. What should I do?

Please email immediately if any item arrives damaged. We will ship a replacement order to you free of charge.

What is the return policy at

Any item may be returned within 30 days of purchase for a refund, minus a 15% shipping and restocking fee. Please fill out our Return Authorization Form and include with your return. Any item that is not working properly and is still within a warranty period may be returned for an exchange. Just fill out our form, describe the problem on the form, and include with your return. If your breathalyzer is giving inaccurate readings, please read our Calibration Questions page before returning your product.