Why Are EtG Tests Performed?
An EtG test, short for ethyl glucuronide test, is often used for people on OWI probation to check for alcohol use. If you are on probation in Michigan, you are usually required to avoid drinking. Testing can happen on a set schedule or with no advance notice. You might be called in. You might be tested the same day.
A positive EtG result can lead to a probation violation being filed against you. This is serious. The court can add penalties, including jail time or even revoking your probation.
If your probation officer informs you of a failed EtG test, it is crucial to contact an Oakland County criminal defense lawyer from Michigan Defense Law immediately. A failed EtG test does not automatically mean the court will find you in violation of your probation. However, failing to address the matter increases the likelihood of such a determination. Call us today at (248) 451-2200 to schedule a consultation.
How Does An EtG Test Work?
There are two basic types of tests that can be administered to check for alcohol consumption. Both types use biomarkers, or physiological indicators, to check for signs that the body has been exposed to alcohol. Indirect biomarkers, such as red blood cells, are used when looking for signs of heavy or ongoing alcohol consumption. Direct biomarkers, such as blood and breath, are used to check for recent consumption. The EtG test uses your urine, a direct biomarker, to check for alcohol consumption within the last 80 hours. While this all sounds very scientific, the reliability of the EtG test itself has been called into question by some very reputable sources such as the U.S. Substance Abuse and Mental Health Services Administration (SAMHSA).
The EtG test was marketed as highly reliable and extremely sensitive when it hit the market just after the turn of the century. Law enforcement, courts and probation departments across the country started using the test to check for alcohol use. Employers also began implementing the test as a screening device or for random safety checks. Not long after its debut, however, the test came under fire as being considerably less reliable than advertised.
How Accurate Are EtG Tests? What You Should Know
The EtG test is a widely used method for detecting alcohol consumption by measuring ethyl glucuronide in urine. EtG/EtS are usually detectable for about 1–2 days in urine; some labs report up to 3–5 days at certain cutoffs. However, their accuracy is not absolute and varies with dose, timing, and assay cutoffs.
One of the main challenges with EtG testing is the potential for false positives. Many everyday products, such as hand sanitizers, mouthwashes, and certain medications, contain small amounts of alcohol. Using these products before testing can sometimes lead to a positive result, even if no alcoholic beverages were consumed. This susceptibility to environmental alcohol exposure raises questions about the reliability of the test in some cases.
There is no single ‘accuracy percentage’ for EtG tests. Sensitivity and specificity vary by cutoff and timing. For example, a commonly used 500 ng/mL point-of-care test that is marketed as an ‘80-hour’ screen was only reliable for detecting past 24-hour use in heavy drinkers in one study; lowering the cutoff increases sensitivity but also increases the chance of picking up incidental alcohol exposure. Best practice is to use EtG with EtS and confirm presumptive positives by LC/MS/MS rather than relying on an immunoassay alone.
While the EtG test is a useful tool for detecting alcohol use, its limitations mean it should be part of a broader assessment rather than the sole indicator of alcohol consumption. Discussing potential factors that might influence test results with a legal or medical professional is essential if an EtG test is required.
Oakland County Criminal Defense Lawyer – Michigan Defense Law
Paul J. Tafelski
Paul J. Tafelski is an Oakland County criminal defense lawyer with more than two decades of experience guiding clients from arraignment through jury trial. Known for a steady courtroom presence and sharp strategic judgment, he has successfully defended hundreds of clients and earned a reputation as an outstanding advocate dedicated to protecting freedom and the future.
A graduate of Michigan State University and the Detroit College of Law at MSU, Paul is admitted to all Michigan state and federal courts. He is active in the Michigan Bar Association, American Bar Association, Criminal Defense Lawyers of Michigan, the Oakland County Bar Association, and the Advocates (Polish Bar Association). His work has been recognized by Super Lawyers (2011–2013, 2017–2021) and as a Leading Lawyer (2017).
Michigan EtG Test Problems
Despite the fact that the EtG test is treated as an acceptable and reliable method of checking for alcohol consumption, it is far from reliable. Given the fact that people stand to lose their freedom as a result of the test, its accuracy should be beyond question.
On the contrary, SAMHSA itself issued a 2006 advisory warning that the test is “scientifically unsupportable” and “should not be used as the sole basis for legal or disciplinary action.” A 2012 update reiterated that EtG/EtS are highly sensitive and can be positive after low-level exposures, recommending corroboration and confirmation by GC/MS or LC/MS/MS for any presumptive immunoassay positive.
The main problem with the EtG test is that it is actually too sensitive. While it does detect alcohol in urine, it cannot determine the source of the alcohol. Using alcohol-based hand sanitizer can produce measurable urinary EtG/EtS and has even produced positive results under sustained/frequent use, but the levels and timing differ from beverage alcohol; this is why confirmation and context are essential. The bottom line is that this unreliable test should not be used as the sole basis for determining that you have violated your OWI probation.
Practical Tips to Reduce Accidental Positives
To cut the risk of accidental positives on an EtG test, treat everyday alcohol like a trigger. Switch to alcohol-free mouthwash, hand sanitizer, aftershave, perfumes, hair products, and cleaning sprays. Hand sanitizers alone have produced measurable EtG and EtS in urine, so soap and water is the safer bet. Read labels on cough syrups, tinctures, and herbal drops and ask for non-alcohol formulations. Skip kombucha, kefir, non-alcoholic beer or wine, and fermented foods for several days before testing.
Give yourself a buffer. EtG/EtS are often detectable 1–2 days, though some labs report up to 5 days at certain cutoffs so plan zero exposure in that window. Stay hydrated, use the restroom, and avoid extreme fluid loading that can complicate creatinine correction. Keep an exposure log with dates, products, and doses. Save receipts for any medications. If you work around sanitizer or solvents, note your shifts.
On test day, tell the collector about all products and medicines, and ask that EtG be tested together with EtS and that any positive immunoassay be confirmed by LC/MS/MS. Using a 500 ng/mL EtG screening cutoff can reduce incidental-exposure calls.
If a low positive appears, call an Oakland County criminal defense lawyer promptly. Your lawyer can review the lab data, request retesting, check creatinine and pH, compare findings to your exposure log, and present scientific advisories showing that EtG alone should not be used as the only proof of drinking. That practical approach protects you and your case.
| Category | Practical Tips | Notes / Examples |
|---|---|---|
| Avoid Everyday Alcohol Sources | Use alcohol-free mouthwash, sanitizer, aftershave, perfumes, hair products, cleaning sprays. Prefer soap & water. | Hand sanitizers can produce measurable EtG/EtS. Avoid kombucha, kefir, non-alcoholic beer/wine, and fermented foods before testing. |
| Timing & Exposure Window | Plan zero exposure for 1–2 days (up to 5 days possible). Stay hydrated and urinate regularly. Avoid fluid overloading. | Labs may detect longer depending on cutoff. Extreme hydration can complicate creatinine correction. |
| Recordkeeping | Keep an exposure log of dates, products, and doses. Save receipts for medications. Note work shifts if around solvents/sanitizers. | Helps compare your log with lab results. |
| Test Day Preparation | Tell collector about all products & medicines. Request EtG + EtS testing. Ensure positives are confirmed by LC/MS/MS. | Ask for 500 ng/mL EtG cutoff to reduce incidental exposure results. |
| If You Get a Low Positive | Contact an Oakland County criminal defense lawyer. They can review lab data, request retesting, check creatinine & pH, and use scientific advisories. | EtG alone should not be used as the only proof of drinking. |
What Can You Do If You Failed the EtG Test?
The first and most important thing you can do if you are informed that you failed an EtG test in Michigan is to contact an experienced Oakland County criminal defense attorney. Just as when you are accused of a crime, you have the right to defend yourself when you are accused of violating a condition of your probation. You have the right to challenge the reliability of the test used as evidence against you.
You have the right to due process when accused of a probation violation. This means that you are entitled to a hearing before the court. Unlike a criminal trial, the prosecutor does not have to prove the violation beyond a reasonable doubt. Instead, a probation violation must be proven by a preponderance of the evidence. Challenging the validity of the EtG test results can cast doubt on the likelihood of the violation.
At Michigan Defense Law, our experienced Oakland County criminal defense lawyers are dedicated to helping individuals protect their rights and freedoms. We can provide guidance and representation to challenge the evidence against you, including unreliable EtG test results. Reach out today at (248) 451-2200 to discuss your options and work toward the best possible outcome for your case.
