Nima Parto, Breathalyzer Test Expert

Nima Parto is the Internet sales manager for He graduated from the University of California-Irvine with a bachelor of arts in political science and economics and was gracious enough to grant us an interview on the subject of breathalyzer tests.

How does a breathalyzer device work?
Alcohol breathalyzers work by measuring the direct correlation between a person's blood alcohol concentration (BAC) and their breath alcohol contents (BrAC). When an individual consumes alcohol, the alcohol in a person's blood stream vaporizes and is excreted through the lungs when exhaling. The ratio of breath to blood alcohol is 2,100 to 1. Essentially every 2,100 milliliters of alveolar air will have the same amount of alcohol as 1 milliliter of blood. Using this formula, alcohol breathalyzers are able to use electronic sensors and to determine a person's blood alcohol concentration.

How accurate are breathalyzer tests?
High quality breathalyzers are very accurate. With most high-end semi-conductor breathalyzers, you will find accuracy to be +/- 0.01% at 0.10% BAC. With a fuel-cell breathalyzer, it is typical to find accuracy to be +/- 0.005%.

With any market, you will find a wide range of breathalyzers. Each will provide a different level of accuracy, durability, and effectiveness. An alcohol breathalyzer is a complicated device that can differ in features from pressure checks, deep lung sampling times, replaceable sensors modules, types of sensors, LCD display, mouthpieces, dot approval, and so on. While it is possible to find $20-$40 breathalyzers, one should expect to follow the "you pay for what you get" purchasing principle. These cheaper breathalyzers lack some, if not most features of a serious alcohol breathalyzer.

Are there any significant differences between the breathalyzer devices that law enforcers use versus the devices for sale to consumers?
Most law enforcement agencies use two types of alcohol breathalyzers; a DOT-approved screening device when out in the field as a tool when alcohol is suspected and a desktop evidential breathalyzer used to print and present evidence to a court.

At the consumer level, some breathalyzers are packed with many of the same features that law enforcement agents use and have been approved by the DOT as a screening device. Most law-enforcement agencies use the more advanced fuel-cell breathalyzer technology and calibrate their devices on a routine basis to ensure accuracy out in the field. It is very uncommon to find law enforcement agencies purchasing low-quality breathalyzers designed for consumers. However, it is very common to find agencies purchasing professional models ($150-$300) designed for the consumer level.

What sort of training or certification is required to administer a breathalyzer test that provides legally admissible results?
To provide legally admissible results, the tester must complete the breath alcohol technician (BAT) certification-training course. In addition, an evidential tester such as a desktop unit with printing capabilities must be used.

How do alcohol breathalyzers differ from other testing methods? Is one method more accurate than another?
Alcohol testing methodologies vary from digital, blood, chemical, saliva and urine. In all cases, a blood test is going to provide you with the most absolute accurate results. A digital breathalyzer will be able to analyze your results and make sure that the testing environment is stable enough to provide accurate results.

Chemical testers that use a chemically coated crystal are very accurate breathalyzers. However, they will only determine if the individual has exceeded the threshold of alcohol for that tester. If the test is for 0.08%, and the person is 0.12%, then the crystals will change colors. If they are below 0.08% then the crystals will remain the same. This is well-received when testing for a zero-tolerance or legal limit. The drawback is that you will not know how much under or over the individual is from the test threshold.

Urine and saliva testing are accurate but there is always the possibility for a false-positive test result. Alcohol in the urine stream can stay with an individual long after it has left the blood stream. Saliva also poses the risk of testing any alcohol residue on the lips or gums, instead of the alcohol vapor that is exhaled from the lungs. This residue can trigger a higher reading of alcohol than what is actually present.

What advice can you give to people who wish to purchase their own breathalyzer?
We always recommend our customers do their fair share of research before purchasing a breathalyzer. We highly recommend staying away from any breathalyzer below $40, as they usually don't provide anything close to accurate results. When looking for a breathalyzer, consider the cost of ownership for the device. Inherent with any breathalyzer, the sensor will become less effective over time and the margin of error will increase, or the device will stop working. To correct this, routine calibration is needed. This usually entails a service charge of $35-$40, shipping to the service lab and return shipping. Newer devices solve this problem by allowing users to replace their sensor themselves. They simply purchase a new sensor module, pull out the old sensor and plug in the new one. Now they have a brand new factory pre-calibrated sensor installed in their breathalyzer without the worry of sending their device away.

In Summary
We highly recommend that individuals never drink and drive. A breathalyzer is used as a tool to help you determine your drinking limit. It is important to note that even if you feel unable to drive and a breathalyzer reads below the legal limit, you should not get behind the wheel under any circumstances. Always drink responsibility.

For more information on breathalyzer tests, please read our Breathalyzer Test Guide. To find a breathalyzer, please visit our Breathalyzer Directory.
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