urine alcohol tests

There are two kinds of urine alcohol tests. The first identifies the presence of ethanol (beverage alcohol) in urine. After alcohol is consumed, some is broken down in the body. Some leaves through the breath, perspiration, feces, and urine. A weakness of the test is that it can’t identify alcohol in the urine for longer than about one to two hours after all alcohol has left the body. And alcohol leaves the body rather quickly. For more on estimating that speed, visit How Long Does Alcohol Stay in the Body?

Another weakness of this type of urine alcohol test comes from a yeast, Candida Albicans. It’s commonly found in the body. Unfortunately, it can change sugar in the urine into alcohol. It can do this while urine is in the bladder or in the sample vial. This is an especially serious problem for diabetics.

A second type of alcohol urine test doesn’t look  for alcohol. It looks for one of the by-products caused as it breaks down in the body. That substance is Ethyl Glucuronide, commonly called EtG.

The advantage of an EtG test is that EtG remains in the body (and urine) long after all the alcohol is gone. The exact length of time is unclear. It probably depends on a number of factors. Claims vary. Some claim that EtG can last “up to 70 to 80 hours.” Others say “approximately 80 hours,” “up to 80 hours,” “3 to four days,” etc. Such claims usually come from those who sell the tests. Independent researchers tend to report much shorter times, such as 24 hours.


Because they can test for longer periods of time than traditional urine alcohol tests, they have wider uses. They are typically used when a person is required to be totally abstinent for a certain length of time. It could be either temporarily or permanently. Here are examples.

  • People under the legal drinking age. Also members of the military services in combat zones where drinking is prohibited.
  • People on probation for alcohol-related crimes.
  • People who have previous alcohol-related problems but have been granted visitation with, or custody of, children. This on condition that they drink no alcohol.
  • Drivers convicted of alcohol-related traffic offenses and required to abstain as a condition of keeping licenses.
  • Professionals who, because of alcohol problems, have agreed to abstain and be monitored as conditions for continued licensure or employment. Such professionals include airline pilots, medical personnel, and lawyers,

In addition, EtG urine alcohol tests can be used by clinicians to motivate clients to be abstinent.  The tests  can be used by researchers to assess the effectiveness of alcohol intervention programs. They can also be   or by parents to discourage underage drinking. The latter use is promoted by sellers of test kits.  However, it is highly controversial. The American Association of Pediatrics discourages home testing by parents. The same is true other leading professional organizations. The many problems associated with such testing may far outweigh any assumed benefits.

An EtG test should not be used with people who are permitted to drink while on their own time but are prohibited from drinking at work. An alcohol breath test would be appropriate. But the many problems with its accuracy should be considered. Learn more at Alcohol Breath Tester Accuracy.

Shortly after the introduction of EtG urine alcohol tests, problems emerged. Many credible people insisted that they tested positive after being completely abstinent. Published research also suggested that the test might be unreliable. There was increasing concern that the test might give false positive results. That is, that the test might falsely indicate drinking among abstainers.

The federal government issued a bulletin cautioning against using EtG urine alcohol tests in connection with “‘[l]egal or disciplinary action[s]’ as ‘primary or sole evidence’ because it is currently only a ‘potentially valuable clinical tool’ whose ‘use in forensic settings is premature.’” It still maintains that warning.

In a 2013 edition of that bulletin, the government reported that “At issue is whether exposure to alcohol or to the vapors of alcohol in many commercial products, such as personal care items, over-the-counter medications, cleaning products, desserts, wine vinegar, and the like or combinations of these products can cause elevation in EtG…that could suggest the person has resumed drinking. Exposure to these products, combined with possible influences of individual variables such as gender, age, and health status on alcohol biomarker responses, is still being studied.”

EtG urine alcohol tests can falsely report alcohol consumption among abstinent people who have eaten Foods containing flavoring extracts. Foods cooked with wine or other alcoholic beverages. Flambé dishes such as cherries jubilee, bananas Foster, and baked Alaska.

Another source of false positive readings are personal care products. These include many Mouthwashes. Aftershave lotions. Colognes. Perfumes. Antiperspirants. Hair sprays. Mousses. Cosmetics. Astringents. Bug sprays. and body washes.

Other sources of false positive results include health products such as medications, herbal therapies, and cough syrups. Ethel alcohol is also found in many household products such as detergents, cleaners, solvents, lacquers, paints, and surface preparations. In fact, there are hundreds of household products containing ethanol. This, according to the Household Products Database of the National Library of Health. Either skin contact or inhalation of vapors can be sufficient to yield false positive results from many of these common products.

The Substance Abuse and Mental Health Services Administration (SAMSHA) warns that “False positive responses can be detrimental in medical and forensic settings where an individual’s freedom or career is in jeopardy.”

Researchers are tried to learn “the degree to which extraneous exposures and conditions affect EtG levels to determine how EtG can be used successfully to indicate intentional alcohol use. In addition, more research is needed on how the test results may be influenced by various diseases, ethnicity, gender, genetic variation in enzyme systems, or the use of drugs." More study is also needed on the fact that under certain conditions, EtG may also occur when certain bacteria along with ethanol-producing bacteria are both present in a container holding the urine sample.

It’s not surprising that the use of EtG urine alcohol tests remain highly controversial.9 They’v never been approved by the US Food and Drug Administration (FDA).

People subject to EtG urine alcohol tests need to be extremely careful to avoid any and all products that might cause false positive results. Their personal freedom or livelihood may depend on it.

Unfortunately, the answer to the question,”How long can urine alcohol tests detect drinking?,” is far from clear.

Adam Lee Nemann
Connect with me
Trial and Defense Attorney, Adjunct Professor of Law at Capital University, founder of Nemann Law Offices
Join The Conversation
Mike D 10/19/2020 09:04 PM
Another similarly problematic test is the PETH test. In use for about ten years now, false positives are finally becoming so common that the situation is nearing critical mass. In the mean time doctors, nurses, pharmacists, pilots, lawyers and child custody cases yield victims by the hundreds... I’m currently collecting information, please comment here if it has affected your livelihood.
Post A Reply
Post A Comment

Blood Alcohol Calculator