What is hair alcohol testing?
A hair alcohol test is used to determine if a person has consumed alcohol over a certain period of time. The test works by examining the Etg (Ethyl Glucuronide) and FAEE (Fatty Acid Ethyl Esters) markers in your hair, and is one of the most accurate and established methods for testing alcohol consumption.
EtG and FAEE are both direct markers of alcohol consumption and are only produced when a person has consumed alcohol or has increased blood alcohol levels. They are absorbed into the hair via sweat and diffusion, and contaminate the entire length of the hair, meaning it is not possible to segment the hair, e.g. if you haven’t consumed alcohol for 5 months but then excessively drink during one month, the alcohol markers would be found throughout the entire length of the hair.
Testing for EtG markers can show a change in the pattern of alcohol consumption, and is the most reliable hair test when determining the levels of alcohol consumed, and FAEE testing is designed to show the long-term alcohol consumption habit. It is advised that hair testing should be combined with another testing method, such as blood testing, in order for the results to be as accurate as possible.
What can the results show?
Testing hair for alcohol is often used to determine alcohol abuse but it can also be required to show abstinence. The type of hair tested will determine what results are available. Testing head hair can show alcohol abuse, abstinence, or social drinking, chest or arm hair can show alcohol abuse or abstinence, and pubic hair can show abstinence. Head hair is the preferred sample.
How much hair is needed?
Approximately 200 strands of hair are required for testing. The hair samples will be 3 or 6cm long, depending on the time period your client needs to be tested for, e.g. 3cm of hair will cover a 3-month period.
What type of hair can be tested?
Head, arm, chest, and pubic hair can all be used for alcohol testing, however, the reliability and accuracy varies. Head hair is the preferred sample as it provides the most accurate picture of alcohol abuse. Arm and chest hair can determine excessive alcohol abuse but the time period is not as concise as head hair. It is not advised to use pubic hair as the test is designed to detect ethanol, and urine has a high concentration of ethanol, leading to false-positive results. Read our blog post on the different types of hair tested for more information.
What if you have no hair?
There are alternative tests available if your client has no hair. In some cases, if a person is required to undergo a hair alcohol or drug test, they may shave off all their hair. In cases such as these, fingernail or blood tests can be used.
How reliable are hair alcohol tests?
Testing hair for alcohol abuse is one of the most accurate and reliable tests available. However, the results of a hair test can be affected by different hair treatments, and for this reason, we recommend combining the test with a secondary method, such as blood alcohol testing, in order to get the most accurate results.
What can affect the results?
A range of treatments can affect the results of hair tests, such as sprays, gels, bleaching, straightening, and perming. Before a test is performed, it is important to submit a list of used hair products to the laboratory to avoid incorrect results. Read our comprehensive guide on what affects a hair alcohol test result for more information.
What are the detection periods?
A hair alcohol test allows us to trace alcohol consumption for 3 or 6 months.
What about blood or urine tests?
Although blood and urine can both be used to detect alcohol consumption, the period of detection is much shorter. A blood alcohol test can only trace alcohol for up to 30 days, and a urine test can only detect alcohol for up to 4 days.