ETG Test Facts And Myths

Posted by Dr Mike Garside on

ETG test facts and myths

The ETG alcohol test

ETG testing in urine is a very useful way of monitoring abstinence from alcohol in those in recovery, or in occupations or institutions where there may be a zero tolerance to alcohol ingestion. ETG, ethyl glucuronide, is a breakdown product of alcohol that can be detected in urine, long after the alcohol has left the system.

Here are some useful facts and myths concerning the ETG test and its limitations and uses. 

Does an ETG test tell you how much alcohol was taken or when?

Alcohol (direct ethanol) screening in urine samples using an ETG test can cause confusing results if you are trying to find out home much alcohol was consumed and when. Any attempt to interpret positive ETG test results often leads to digging enormous holes for the testing agent or authority.

Our advice if you want to know how much alcohol was consumed, and if the person is under the influence of alcohol at the time they are being tested, is to use a breath alcohol test, a saliva alcohol test or a blood alcohol test, rather than an ETG test. 

Does an ETG test tell you if no alcohol was used in the last 80 hours?

The ETG test for alcohol attempts to solve the problems associated with simply screening urine for the presence of ethanol. The ETG test also extends the useful period for detection, making it of particular value in abstinence programs.

Put simply, an ETG alcohol test can detect if a person used alcohol, long after the alcohol (ethanol) has been completely excreted from the body.

After drinking alcohol, the alcohol itself is detectable in urine after only 10-20 minutes, and will continue to be excreted through the kidneys for as long as the alcohol remains in the renal blood flow.

Ethanol is metabolised (broken down) by the liver, and cleared at a physiologically very variable rate. Liver enzymes, notable GGT break down the ethanol to glucose and water. 

Meanwhile in the bladder, urine containing ethanol may not be passed for many hours, the concentration of the ethanol in urine over this period may vary considerably as new urine is produced. The result is that the level of alcohol in urine can not be used to determine the amount or time of alcohol consumption, only that it has been consumed in the period prior to sampling. How long is the time frame for detection ? You can't say.

Now let's consider testing with an ETG drug testing kit. Still no information can be concluded about how much alcohol was consumed, or the exact time of consumption but the detection period after use is now extended to 80 hours. This is a much more useful result to have especially if you are screening for alcohol consumption in a rehab or zero tolerance program.

A negative ETG urine drug test indicates zero alcohol exposure in the 80 hours prior to the ETG test.

Is a positive ETG test specific for consumed alcohol?

What mitigation factors can be presented for a positive ETG test?  In theory alcohol produced in some metabolic disease such as severe diabetic ketoacidosis could be detected by an ETG test. However the severity of the disease to trigger a positive ETG test result should be apparent at the point of sampling. The person would have been so ill as to warrant emergency inpatient treatment.

The cut off level of the ETG test is set to exclude ethanol in mouthwash, tiramisu and trifle. If the person whose urine you are testing for ETG does not have the motivation to avoid these things when they know that they are going to be tested, you have a motivation problem.

So in summary

  • Does an ETG test tell you when alcohol was used..No
  • Does an ETG test tell you how much alcohol was used..No
  • Does an ETG test tell you if no alcohol was used in the last 80 hours..Yes
  • Is ETG specific for Ethanol?..Yes
  • Can an ETG test detect naturally produced alcohol (ethanol) in metabolic diseases, In theory yes, but practically no, as the cut off is above the levels which would normally occur in all but the most severe episodes.

ETG alcohol test strips can be purchased online here


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