- Possibly the most recognizable type of alcohol testing, breathalyzers are popular because they are portable and offer instant results for officers and emergency workers in the field. Unfortunately, according to an article by David J. Hanson Ph.D., breathalyzer results vary up to 15 percent from actual BAC, and "at least 23 percent (that's about one out of every four) of all individuals tested will have a BAC reading higher than their actual BAC." This is because breathalyzers do not directly measure the blood; instead, they measure the alcohol passed into the alveoli air sacs as blood flows through vessels in the lungs.
- Due to the variable accuracy of breathalyzers, field sobriety tests also used to further verify intoxication. During a field sobriety test, individuals are required to complete basic tasks; response time and hand-eye coordination are measured as a determining factor. Commonly, field sobriety tests consist of a one-legged stand; walking a straight line and turning around; and the horizontal gaze nystagmus test, in which individuals are asked to focus on an object placed between 12 and 15 inches away.
- A very inexpensive method of alcohol testing, urine testing is common among businesses that want to test their employees. Unfortunately, this method of testing is limited to detecting recent alcohol use, and alcohol users can "cheat" by smuggling a friend's alcohol-free urine into the testing room. However, if done within less than a week after suspected use, and if cheating is actively dissuaded, urine testing results are very accurate. Additionally, urine testing is useful because the obtained sample can also be used to test for other substance abuse besides alcohol.
- Unlike urine tests, saliva tests cannot be easily fooled, and unlike breathalyzers and field sobriety tests, they are very accurate. Unfortunately, this type of testing is more expensive than urine testing, and it can detect alcohol usage only within the past day or two. Saliva tests can also be used to check for drug usage. The procedure itself is often preferred by individuals being tested because it is less personally invasive than urine testing, as saliva is generally a less taboo bodily fluid than urine.
- Hair analysis provides an accurate test for long-term alcohol usage. However, it is very expensive when compared with the other lab testing methods. The test measures EtG and FAEE absorption levels in the person's hair. EtG and FAEE compounds are absorbed by a person's hair only when alcohol is present in the bloodstream, so frequent absorption of these compounds indicates frequent prior intoxication. Hair testing is more discreet, as hair samples can be obtained outside of the medical environment required for obtaining saliva and urine samples.
