Last updated: October 2, 2023
In short, the ethyl glucuronide (EtG) test is used to see if a person has been drinking when they shouldn’t be. EtG is the product left behind after alcohol completes the metabolization process. So, unlike a breathalyzer test that detects current alcohol impairment, the EtG alcohol test identifies prior alcohol use. It’s used to monitor behavior rather than discovering intoxication.
Sometimes whether or not someone remains abstinent and refrains from using alcohol keeps life from taking a turn for the worse.
Why would you need to administer an EtG test?
There are cases when it’s important to know that a person is abstaining from alcohol. For some individuals, drinking isn’t allowed in certain situations—ever.
The following are examples of when testing for prior alcohol consumption may be required.
- Jobs such as an airline pilot, doctor, attorney, and other professionals when being sober is very important. They could possibly put another person’s life at risk if they were impaired.
- It may be a stipulation of probation or parole.
- Court cases when showing sobriety is required.
- A person who needs a liver transplant should not drink under any circumstances.
- Some schools require abstinence as a condition of continued enrollment.
- A program for those who were driving under the influence (DUI) often requires abstinence.
- Programs that treat alcoholism, such as an addiction treatment center or facility, often monitor their patients.
A socially acceptable drug
Drinking too much is one of the most common types of substance abuse in the United States. For example, according to a 2017 National Survey in Drug Use and Health (NSDUH), nearly 86.3% of those over 18 reported drinking alcohol at some point in their lifetime. And, 55.9% reported drinking in the last month.
Binge drinking is defined as a man having five or more drinks and a woman having at least four drinks at the same time or within a couple of hours on at least a single day in the past month. This definition is from the Substance Abuse and Mental Health Services Administration. The 2017 statistics reported 26.4% of those 18 and older said they engaged in binge drinking in the previous month. Of those, 6.7% said they were involved with heavy alcohol use in the last month.
We’re happy to report that these statistics are down a bit from the 2015 NSDUH which were nearer to 27% and 7% respectively.
Keep promoting the dangers of addiction! Slow and steady wins the race.
Even though all traditional test methods are not applicable to administer the EtG test, there are options available to monitor alcohol use.
Urine EtG test
The most commonly used method to look for EtG in someone’s system is the urine test. This test identifies EtG in urine for up to five days after a person consumes alcohol. Of course, if one knows the test is coming, abstaining for a few days is the best choice. However, refraining from use seems impossible for some. For instance, the user may justify use with the intent of taking “just a sip” rather than consuming enough to actually register on an EtG alcohol test. Then, after the first sip, it becomes harder and harder not to take another and another and—
In contrast, using a breath test to detect alcohol only shows alcohol consumed in the last several hours. A breath test identifies how intoxicated a person is, rather than how often a person drinks.
Another way to monitor a person’s alcohol intake is by using a transdermal alcohol monitor. It detects alcohol through the skin. Transdermal monitoring is becoming more popular, however, this wearable device is costly and inconvenient to use.
Should someone try to falsify the test results by diluting their urine in hopes of masking alcohol use, it throws off the creatinine levels in the urine. The test is deemed inconclusive at that point. The subject may be required to take a second test.
EtG can be detected in urine samples by using a standard immunoassay (IA) test. It’s quick and not too expensive. The majority of EtG tests are negative, of course, however, positive results using the immunoassay test should be confirmed using the liquid chromatography with tandem mass spectrometry (LC/MS/MS) test. In addition to confirming the initial screen result, the LC/MS/MS also identifies EtG levels.
What do the urine test results mean?
According to a study published by the Drug and Alcohol Dependence Journal, the EtG test can detect light and heavy drinking within a certain number of days. The results depend on what level of EtG, or “cutoff,” is used.
“High” positive EtG test (for example, 1,000 ng/mL) may indicate:
- Heavy drinking on the same day as the test or on the previous day
- Light drinking on the same day as the test
“Low” positive EtG test (for example, 500 to 1,000 ng/mL) may indicate:
- Heavy drinking within the last one to three days
- Light drinking within the last 24 hours
- Recent (within the last 24 hours) intense exposure to environmental products containing alcohol
“Very low” positive EtG test (for example, 100 to 500 ng/mL) may indicate:
- Heavy drinking within the last one to three days
- Light drinking within the last 12 to 36 hours
- Recent exposure to environmental products containing alcohol
The EtG alcohol test accurately detects recent alcohol consumption at least 70% of the time by detecting EtG levels contained in the urine. It’s even more accurate in determining whether or not someone is using alcohol heavily.
Court systems have accepted EtG urine alcohol test results as admissible evidence.
Blood EtG test
Unlike other test methods, the blood test detects both current impairment and the EtG metabolite. Alcohol is only identified in the bloodstream from between six to twelve hours. However, EtG blood tests detect the metabolite for up to 36 hours after taking the last drink.
Blood tests are very invasive, not to mention expensive, so are rarely used. When required, a liquid chromatography/mass spectrometry (LC/MS) test measures EtG levels in the bloodstream.
Hair and nail EtG tests
As with other drugs, the hair follicle test detects alcohol use for a ninety-day period. EtG metabolites stored in the hair follicle grow out into the center of the hair shaft leaving a permanent record of drug use. Lab technicians perform an LC/MS/MS to test for EtG in the hair.
Lab technicians cut the hair sample to the normal test length of one and one-half inches. Hair grows about one-half inch per month which determines the 90-day identification period. As with the urine test, exposure to environmental products containing alcohol can reflect in the test results. They can also tamper with nail test results.
Keratin, a hardened protein, compose hair and fingernails. A 3-millimeter nail specimen detects drug or alcohol use for up to an eight-month period. However, the National Center for Biotechnology Information (NCBI) studies show the fingernail test to be “an objective long-term qualitative indicator of any alcohol use” up to 12 weeks.
Are there any limitations to EtG testing?
We’ve mentioned that EtG testing isn’t a test for current impairment.
We’ve also mentioned that using certain environmental products containing alcohol can cause a positive result in an ETG test. People are more likely to associate alcohol as being an ingredient in the following household products.
- Certain cosmetics
- Hand sanitizers
- Breath spray
However, these are just a few examples of products containing ethanol that can cause a false positive result on an EtG test. The U.S. Department of Health and Human Services has compiled an extensive list. You find alcohol in a wide range of household products from household cleaners to cosmetics. There is even alcohol in pet products such as flea and tick spray. Those subjected to EtG testing should scan a product’s ingredients before purchasing them.
False-positive results pose big problems
Because it’s possible for environmental products to cause false-positive results, some claim that the EtG test shouldn’t be used. This is because a false positive result can have detrimental consequences on someone’s life. For instance, it’s possible that someone who’s in the midst of a custody battle who tests positive could lose custody of their child because they inadvertently used several household products containing alcohol. Likewise, someone on parole could wind up back in jail or a kidney transplant recipient could be in hot water with the medical staff until resolving the issue.
Overall, though, the EtG alcohol test serves its purpose extremely well. It’s a huge deterrent for those who must refrain from alcohol use. Knowing there is definitely an EtG test in the future gives someone the resolve to push through that urge for “just one sip” far more often than not.
Addiction recovery is truly a one-day at a time lifestyle. You may resolve to never drink again, but you never know when the urge will strike with overwhelming force. Those required to report for EtG testing may consider it as much a tool for maintaining sobriety as the one who required they take it.