A Breathalyzer® test is a specific brand name of devices for gauging blood alcohol content (BAC) based on the quantity of alcohol in a person's breath. There are different companies that manufacture blood alcohol content estimating devices, but the Breathalyzer® brand name has become synonymous with the devices in general. Breathalyzer® tests are ordinarily used by law enforcement agencies in order to determine the alcohol intake of someone who has either been pulled over while driving or, in some cases, arrested for public intoxication or other offenses. The commercial availability of a Breathalyzer® test, however, is also allowed for use by consumers. While the Breathalyzer® test has been approved for law enforcement use in many areas of the world, there are some limitations to its functioning.
The theory that the quantity of alcohol in a person's blood can be determined based on the level of alcohol in his or her breath dates back to at least the 1870s, and its first practical use for police testing was created with the Drunkometer in 1938, though the device was too large for much portable use. Dr. Robert Borkenstein, a professor at Indiana University at Bloomington who was previously a captain with the Indiana State Police, is generally considered to be the inventor of the first real Breathalyzer® test in 1954. The name Breathalyzer® is a combination of the words breath and analyzer. Smith & Wesson was the first commercial manufacturer of Breathalyzer® tests, though they later sold the brand to National Draeger.
Law enforcement agencies generally have two formats of the Breathalyzer® test: a hand-held device for testing that is used away from the police station and a desktop analyzer for testing inside a law enforcement facility. The use of a hand-held testing device is often referred to as a field sobriety test. Police officers use a field sobriety test to determine if the subject of the test is to be arrested under the charge of driving under the influence (DUI) or driving while impaired (DWI). This drunk-driving test is sometimes called a preliminary breath test (PBT) and further testing, sometimes including a blood test, is usually done once the subject has been taken to police facilities.
Consumer versions of the Breathalyzer® test are also manufactured, though they are generally of lesser quality than those possessed by law enforcement agencies. These allow a motorist to estimate whether or not he or she would pass a Breathalyzer® test if stopped by law enforcement. Certain chemicals and chemical compounds, whether in the air or in the breath of the subject being tested, have been determined to interfere with the functioning of Breathalyzer® tests. In fact, certain products are manufactured that claim to allow an intoxicated subject to pass a Breathalyzer® test, though the reliability of these products has not been determined.