A compliance management organization model for drug screen delivery

EtG Alcohol Testing Revisited – Urine vs. Oral Fluids

The development of EtG (Ethyl Glucuronide) technology vastly improved the ability of caseworkers and courts to make informed decisions about client alcohol use. Before EtG, alcohol screens were limited in terms of detection windows. The availability of EtG increased that detection window from at most 24 hours to a median of three days in urine.

But does that hold true for all testing technologies, or are some better than others? Let’s take a look at EtG oral fluid vs. EtG urine screening.

There is no one best method of substance testing. We’ve been preaching that sermon for as long as we’ve been in business. The answer varies, and it almost always depends on exactly what you’re trying to prove or disprove with the screen. For example, if you were trying to determine if your client used Marijuana within the past two months, a hair test would be your best option, as it detects drug use for up to three months. If you wanted to determine if the client used Marijuana today, an oral fluid test would be your best bet, because the strength of those tests lies in determining very recent use–typically a day or less. If you wanted to determine if your client used Marijuana sometime during the past week, a urine screen would be your best choice. Marijuana is detectible in urine for one to three days (occasional user) and up to thirty days for a chronic user.

But what about alcohol?

A blood Ethanol test or a breathalyzer can both be used to confirm or rule out current intoxication. But a blood test is costly, invasive, and as with the breathalyzer, the detection window is measured in hours, not days. So that leaves oral fluid tests and urine tests.

 If you’re only testing for Ethanol–the standard alcohol test–there’s not much difference between the two approaches. The detection window is a little bit longer in the urine screen but not all that much longer. But when alcohol is the drug of choice, people tend to want to detect intake back even further. That’s why so many have opted to test using the EtG technology. EtG doesn’t test for Ethanol, but rather for a biomarker that the body releases when Ethanol is consumed. EtG can be detected in urine long after Ethanol is out of the system. In fact, historical Span results on randomly scheduled screens revealed a positive rate on urine Ethanol tests of 2.61% while randomly scheduled EtG screens had a positive rate of 8.96, better than a three-fold increase.

What about oral fluids? In a 2011 study published by the Journal of Analytical Toxicology  (Gudrun Høiseth, et. al.), the authors found that, “the detection time for EtG in oral fluid is…only a few hours longer than for ethanol itself and represents limited additional value.” In fact, the maximum detection window for oral fluid EtG was less than 12 hours, while EtG in urine was detectable from 24 hours (small quantity of alcohol ingested) up to five days (larger quantity of alcohol ingested).


In a similar study, Immunalysis Corporation, a leading manufacturer of testing reagents and oral fluid collection devices provided us with a chart outlining slightly different measurements but the same general conclusions.



Clearly, the detection window for EtG in urine is significantly longer than it is with oral fluid. In fact, a standard urine ethanol test is just about as likely to discover alcohol use as is an EtG tested in oral fluid.

With that in mind, we recommend that when requiring an EtG test, you stick with a urine screen. If you must test with oral fluids, don’t waste the extra money on EtG. Your results won’t be much different than if you had opted to screen for Ethanol only. But again, if you want maximum detectability of alcohol use, the urine EtG is hands down the best option.