Alcohol Blood Tests vs. Breathalyzers
When considering the implementation of various testing methodologies for testing a person's blood alcohol
content (BAC), a number of Human Resource directors in various organization and companies need information about
alcohol blood tests vs breathalyzers.
A blood alcohol test (also known as an alcohol blood test and a blood test for alcohol) directly measures
BAC and is the most accurate method for testing a person's blood alcohol content.
A breath alcohol test, such as a breathalyzer test, conversely, estimates blood alcohol concentration or
content indirectly by measuring the amount of alcohol in a person's breath.
Breathalyzers Estimate A Person's Blood Alcohol Content
A breathalyzer is a device that is used for estimating a person's blood alcohol content (BAC) from a breath
In the United States, the Alcosensor, Datamaster, Alcotest Intoxilyzer, and the Intoximeter are the most common
breathalyzer brand names currently in use.
Breathalyzers can detect and measure current alcohol levels. The person blows into a breathalyzer and the
results are given as a number, known as the Blood Alcohol Concentration (BAC) which shows the level of alcohol in
the blood at the time the test was taken.
Since 2002, it has been illegal in all 50 U.S. states to drive with a blood alcohol concentration (BAC) that is
.08% or higher.
Breathalyzers do not directly measure blood alcohol concentration or content. Measuring blood alcohol content
(BAC) requires the analysis of a blood sample.
Breathalyzers, rather, estimate blood alcohol concentration or content indirectly by measuring the amount of
alcohol in one's breath.
Some Key Issues With Breathalyzers
A major issue with some breathalyzers is that they not only detect the ethyl alcohol found in alcohol beverages,
but also in other substances that have a similar molecular structure.
Stated differently, the "problem" breathalyzers identify any compound containing the methyl group molecular
And the issue with this is that more than one hundred compounds can be found in a human's breath at any one time
and 70% to 80% of these compounds contain the methyl group molecular structure.
The consequence of this is that these methyl group molecular structures will be incorrectly identified and
labeled as ethyl alcohol.
Interestingly, the more ethyl group substances the breathalyzer detects, the higher the false blood alcohol
content estimate will be.
The National Highway Traffic Safety Administration (NHTSA) has found that people who are diabetics or dieters
can have acetone levels that are hundreds, if not a thousand of times higher than people who are not diabetics or
dieters. The key issue here is that acetone is one of the many substances that can be falsely detected as ethyl
alcohol by some breathalyzers.
There's also a variety of products found in the environment that can lead to erroneous BAC results with
breathalyzers. Some these products include substances or compounds found in cleaning fluids, celluloid, gasoline,
paint removers, and in lacquers.
Other common substances that can result in false BAC levels are alcohol, vomit, or blood in the person's mouth.
False BAC readings can also be caused from electrical interference, dirt, smoke, cell phones, police radios,
moisture, and tobacco smoke.
Breathalyzers can be very sensitive to temperature and will result in false readings if they are not adjusted or
recalibrated to compensate for ambient or surrounding air temperatures. Moreover, the temperature of the person
being tested is also significant.
More specifically, each degree (in Fahrenheit) in the subject's body temperature above 98.6 can result in a
relatively large elevation (about 8%) in apparent BAC.
A person's breathing rate can also significantly affect breathalyzer results. For instance, one study discovered
that the BAC readings of people who ran up a flight of stairs decreased 11% to 14%.
And when these people ran up the stairs a second time, their BAC readings decreased 22% to 25%. Another study
found similar results (a decrease in BAC of 15%) in people who exercised vigorously or who hyperventilated.
Moreover, hyperventilation for just 20 seconds has been shown to lower the breathalyzer BAC readings by about
10%. Conversely, people who hold their breath for 30 seconds can increase the breathalyzer BAC results by
The failure of law enforcement officers to use the breathalyzers properly and to properly maintain and
re-calibrate the units when necessary also lead to testing errors.
Research indicates that breath tests can vary at least 15% from actual blood alcohol concentration. An estimated
23% of individuals tested will have a BAC reading higher than their true BAC.
Can Breathalyzers be Fooled by Odors?
A common myth is that breathalyzers can be "fooled" by odors that mask the smell of alcohol. Mints, onions, and
mouth wash may indeed disguise the smell of alcohol, but they do not fool the breathalyzer because they do not
change the actual alcohol content on a person's breath.
What can "fool" breathalyzers, however, are products such as breath spray or mouth wash that can raise the BAC
readings due to the alcohol content in these products.
Listerine, for example, contains 27% alcohol, and can significantly raise the BAC test results. Why? Due to the
increased alcohol (from the Listerine) detected on the person's breath, the breathalyzer produces a false high
Stated differently, instead of the reading being based on alcohol in the blood that has been diffused into the
lungs, the breathalyzer will result in a false reading due to the combined alcohol in the person's mouth (from the
Listerine) and from the person's lungs.
A blood test for alcohol (also called a blood alcohol test and an alcohol blood test) is the most accurate
method for testing a person's blood alcohol concentration (BAC).
Blood alcohol tests, moreover, are the most expensive and the most intrusive methods for testing BAC. Due mainly
to their high cost and to their intrusiveness, however, alcohol blood tests comprise the least common method for
testing a person's BAC.
Conclusion: Alcohol Blood Tests vs. Breathalyzers
An alcohol blood test (also called a blood alcohol test or a blood test for alcohol) directly measures a
person's blood alcohol content and is the most accurate method for testing a person's blood alcohol level.
A breath alcohol test, such as a breathalyzer test, on the other hand, estimates the blood alcohol concentration
or content indirectly by measuring the amount of alcohol in an individual's breath.
According to current demographic statistics, alcohol abuse accounts for approximately two-thirds of the total
number of substance abuse complaints in US workplaces. In addition, the use or abuse of alcohol is associated with
nearly half of all industrial accidents.
As a consequence, there is a growing demand for more reliable alcohol detection and testing methods. Indeed, an
increasing number of companies are employing alcoholism screening tests and random alcohol testing as part of their
employee drug and alcohol testing programs.
In a word, more and more Human Resources directors in different organizations and companies are seeking more
detailed information about alcohol blood tests vs breathalyzers so that they can purchase and implement
cost-effective and reliable methods of employee alcohol testing.