Learn why EtG tests are used, how accurate they are, and the truth behind EtG test facts and myths.
EtG Test Uses
The EtG test is used to detect alcohol abstinence in situations that do not allow drinking. These may include:
Alcohol treatment programs Court cases (for example, child custody) DUI or DWI programs Liver transplant patients Probation programs Professional monitoring programs (for example, airline pilots, healthcare professionals, attorneys) Schools or the military
It’s important to note that the EtG test is not recommended for use in workplace testing programs as it does not measure current impairment from alcohol.
Detection Time Frame
The EtG test strips are quite sensitive and can detect even low levels of EtG in the urine. (Remember, the test measures EtG specifically—not alcohol.) The test can confirm that there has been alcohol in the body up to five days after consumption.
EtG Test Accuracy
There are some limitations to this test. The EtG test strips can produce a positive result from exposure to the alcohol that’s present in many daily use products. Environmental or home products that contain alcohol include:
AftershaveBreath spraysCleaning productsCosmeticsFoods prepared with or flavored with alcoholHair dyeHand sanitizersHygiene products like antiperspirantMouthwashes
There are hundreds of household products that contain ethanol, according to the Consumer Product Information Database, and exposure to them could possibly lead to a false positive on the EtG test. But the EtG test strips accurately detect when a person has recently consumed alcohol 70% or more of the time. One study showed that for moderate to heavy drinking, this number jumps to 85%.
EtG Test Results
The following cutoff values have been proposed for test results.
High Positive
A “high” positive EtG test (for example, >1,000ng/mL) may indicate:
Heavy drinking on the same day or the previous dayLight drinking on the same day as the test
Low Positive
A “low” positive EtG test (for example, 500 to 1,000ng/mL) may indicate:
Heavy drinking within the last one to three daysLight drinking within the last 24 hoursRecent intense exposure to environmental products containing alcohol (within the last 24 hours)
Very Low Positive
“Very low” positive EtG test (for example, 100 to 500 ng/mL) may indicate:
Heavy drinking within the last one to three daysLight drinking within the last 12 to 36 hoursRecent exposure to environmental products containing alcohol
How EtG Is Eliminated From the Body
EtG is eliminated from the body over time after you drink water and other fluids that flush it out when you urinate. Although drinking water does help flush EtG out of your system, it’s a myth that you can use this method to reliably manipulate drug test results. Research has suggested that by measuring urinary creatinine (a chemical compound and waste product of urine), health professionals can identify when a urine sample has been diluted or when someone tried to disguise their EtG levels by drinking a lot of water. It’s also a myth that one drink won’t show up on the EtG test. Whether the test detects one drink depends on many factors like how recently you drank, your metabolism, and the alcohol percentage of your drink. But if you drank any alcohol in the past five days, there is a high chance the EtG test will detect it. Remember, EtG tests don’t measure the number of drinks you had. Its job is to indicate whether you’ve had any alcohol at all—not the specific amount.
A Word From Verywell
All in all, the EtG test is considered a highly useful test for detecting recent alcohol consumption. But like any test, there is the possibility for a false positive. This is why a positive test should be confirmed either with another test or with verification from the person that they did indeed drink alcohol. Hopefully, as the research on EtG and other alcohol use indicators unfold, there will be increasingly accurate ways to distinguish between true alcohol use and exposure to alcohol in environmental products.
