Everyday we hear and read about drivers involved in accidents who are charged with DUI or DWI. The media will discuss a suspect’s breath alcohol level and the legal limit for alcohol. A driver might be found to have an alcohol level of 0.15 and the legal limit is 0.08. You probably hear or read the media discuss a “Breathalyzer” being used to test the suspected driver’s alcohol level but are not sure how breath can determine a blood alcohol level or how much someone has had to drink.
Interesting Historical Note:
The terms “Breathalyser” and” Breathalyzer” have become synonymous with all breath alcohol testing equipment. Both names are trademarked and originated from an instrument invented by Dr. R.F. Borkenstein who worked for the Indiana State Police. It was invented in 1954 and the technology behind it is still used today. This fact is for those of you who aspire to appear on” Jeopardy” or” Who Wants to be a Millionaire”.
Back to business…How do you get a blood alcohol level from breath you ask?
Alcohol that a person drinks will always appear in their breath. This is because alcohol is absorbed from the mouth, throat, stomach and intestines into the blood stream. Alcohol is not digested like food or chemically changed in the blood when it is absorbed. When blood passes through the lungs some of the ingested alcohol travels across the membranes of the lungs air sacs or alveoli and moves into the air. This process is one of alcohol’s main properties of evaporating from a volatile solution.
So…the alcohol concentration from lung air is directly related to the alcohol concentration in the blood. It can be detected by a breath alcohol testing device.
What are the best ways to test blood alcohol concentration levels (BAC)?
Blood was the original medium used to test BAC’s. A blood test offers the ability to accurately test the same sample several times, if the sample is properly maintained. On the down side, blood tests are invasive and analysis time is longer. The collection process requires trained medical personnel and the analysis requires precise procedures performed by trained lab technicians. The results are not immediately available. The test is also expensive.
Breath Alcohol Testing is very accurate, noninvasive, inexpensive and can be performed anywhere. There is extensive training required and procedures to be followed but you do not have to have medical personnel to perform the test. It can also be performed anywhere. That is why it used by law enforcement, medical and safety personnel, and educators to name a few.
Urine testing may also be performed to test BAC. It is the least desirable of all the methods. It must be collected in a lab or medical facility and analysis be done by trained lab technicians in much the same manner as the blood test. It is also expensive and not as accurate as blood or breath.
At ExperTox, we can collect and perform all 3 types of alcohol tests. In our Occupational Health department we offer DOT and Non-Dot alcohol and drug testing. We also perform court ordered and tests for the private sector. We normally do breath alcohol tests unless another type is specified by the client.
There are four types of breath alcohol tests:
- Screening – A device is used to test a subject to see if BAC is above limits set by employers or state laws.
- Evidential – A test is done to collect evidence of BAC to be used in court or industry such as post accident cases, reasonable suspicion of use on the job or in traffic violations, and follow-up testing for previous positive tests.
- Interlock – Tests are designated for permanent connection to an electrical system of a vehicle; its purpose is to prevent or deter its operation by persons with alcohol in their system.
- Self Test- Used by people to check their own BAC before working or driving. These have a high degree of accuracy and reproducibility but are not admissible in court.
There are three major types of breath alcohol testing devices, and there based on different principles:
- Alcosensor – Detects a chemical reaction of alcohol in a fuel cell
- Breathalyzer – Uses a chemical reaction involving alcohol that produces a color change
- Intoxilyzer – Detects alcohol by infrared spectroscopy
We use Alcosensor at ExperTox for breath alcohol testing. They are extremely accurate, dependable, easy to use and portable. Intoxilyzer instruments are mainly used for research and by law enforcement. They are desk top devices and are stationary. Breathalyzers are also not used for field work and are more difficult to use and maintain. Operators of any breath alcohol testing device must be trained in use and calibration of the device. Scrupulous records must be maintained.
What are your best bets?
If you insist on drinking and driving, just know you can’t hold your breath long enough to avoid the consequences. Cover-ups such as gum or mints will not do the trick. Your best option is a designated driver or taxi.
Friday afternoons may seem like a time to celebrate, but a beer or two at lunch could get you into real trouble, either by having an accident that might injure yourself or others or by getting caught as a safety violation. Just expect when you blow, your employer will know…. the truth.
Lou Ann Enis, Registered Nurse and Occupational Health Supervisor