EtG Tests Not Reliable

by baronedefensefirm on May 7, 2009

If you are on bond or on probation for drunk driving, chances are the judge has ordered that you abstain from alcohol.  Abstinence is usually monitored by random testing, but a newer test, the EtG test,  is starting to become popular with judges.  The problem is that it is totally unreliable and prone to false positives.  This is a big problem if the judge wants to toss you in jail because of a positive EtG test.

Why EtG Tests are Not Reliable – Compared with other drugs, ethanol is rapidly metabolized to the ultimate end products of just carbon dioxide and water.  Since these chemicals are so common, a test for carbon dioxide or water would mean nothing.  However, the theory behind EtG tests is that after consumption and break down, ethanol (beverage alcohol) leaves behind certain “biomarkers,” or “clues” that may suggest that you have consumed ethanol at some point prior in time.

About 95 percent of the ethanol entering the body undergoes metabolism by oxidative enzymes in the liver.  Alternatively, about one-tenth of one percent is cleared by non-oxidative metabolism into ethyl glucuronide (EtG) and ethyl sulfate (EtS).  These “conjugated metabolites” are excreted in the urine.[i]  Within the past few years it has become both scientifically and economically feasible to perform a urine test to “look” for these direct biomarkers, and this has lead to widespread use these EtG tests in various court and administrative hearings.

EtG tests may become positive shortly after even low-level exposure to alcohol and may remain detectible in urine and other bodily fluids for several days.[ii]  It should be noted however, that these non-oxidative metabolites can also be simply measured using gas chromatography.[iii]  The ultimate question though is whether a positive EtG test should ever be used as de facto evidence of alcohol consumption.  Most assuredly, the answer is “no.[iv]”

What Other Courts Have Said About EtG Tests:

In a 2008 Ohio case dealing with these issues, Cynthia J. Johnson had her license as a physician’s assistant suspended after a single positive EtG test.[v]  In this case Ms. Johnson was diagnosed with alcohol dependence/abuse, and underwent several years of supervision through the Ohio State Board of Medicine.  It was alleged that after four years of demonstrated sobriety, she relapsed.  In making this determination the board relied heavily on a single positive EtG test.  Based on this single test Ms. Johnson’s license to practice was suspended.

In her defense Ms. Johnson’s claimed that the test was positive because she had consumed communal wine at a Christmas mass or was possibly due to her use of topical “everyday” products such as hand sanitizers.

The court overturned the board’s license suspension after finding that the EtG test is not reliable.  They based this determination in part on the fact that the Substance Abuse and Mental Health Services Administration (SAMHSA) of the United States Department of Health and Human Services issued an advisory indicating that there remains an issue “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, my cause elevation in EtG or EtS that could appear to be drinking.”[vi]  They also relied on Dr. Skipper’s testimony that “serious peer-reviewed research remains underway because the science of EtG is not fully understood.”

The court ultimately concluded that while “reliable enough to be admissible, the EtG test must be used with caution.”  Also, that it is “contrary to the rules of law to afford it (a positive EtG test) much weight standing alone,” and that “[L]egal or disciplinary action based solely on a positive EtG test is inappropriate and scientifically unsupportable at this time.”

What You Should do About a False Positive EtG Test:

If you are falsely accused of drinking alcohol based on an EtG test then make sure your attorney is well versed in the law and science involved.  Ask him or her to order my DWI Journal: Law and Science article on which this post is based entitled: The Use of Alcohol Biomarkers in Monitoring Court-Ordered Abstinence.  This article can be ordered from the publisher, Whitaker Newsletters, or have your lawyer call my office for assistance.  Yes, we’re busy, but we’re never too busy for justice!

[i] Johnson v. State Med. Bd. of Ohio, 147 Ohio Misc.2d 121 (Ohio 2008) at 54.

[ii] SAMHSA The Role of Biomarkers in the Treatment of Alcohol Use Disorders, Vol. 5, Issue 4 (September 2006).

[iii] Jones, Biochemical and Physiological research on the Disposition and ate of Ethanol in the Body, Garriott’s Medicolegal Aspects of Alcohol, fifth edition, pg. 176 (2008).

[iv] Id.

[v] Johnson v. State Med. Bd. of Ohio, 147 Ohio Misc.2d 121 (Ohio 2008).

[vi] SAMHSA The Role of Biomarkers in the Treatment of Alcohol Use Disorders, Vol. 5, Issue 4 (September 2006).


This post was written by...

– who has written 203 posts on Michigan DUI and License Restoration Lawyers.

Patrick T. Barone is the author on two books on DUI defense including the well respected two volume treatise Defending Drinking Drivers (James Publishing), and The DUI Book – A Citizen’s Guide to Understanding DUI Litigation in America. He is also the author of a monthly DUI defense column for the Criminal Defense Newsletter, published by Michigan’s State Appellate Defender’s Office. Mr. Barone is an adjunct professor at the Thomas M. Cooley Law School where he teaches Drunk Driving Law and Practice. He is also on the faculty of the Criminal Defense Attorney’s of Michigan’s Trial Lawyer’s College where he provides trial skills training to Michigan’s criminal defense practitioners. Mr. Barone lectures nationally on various DUI defense topics, and he has appeared in newspapers, on television and on radio as a drunk driving defense expert. Mr. Barone has been certified as an instructor and practitioner of the Standardized Field Sobriety Tests and has also attended a 24-hour certification course at National Patent Analytical Corporation (the manufacturer of the DataMaster) and has thereby been deemed competent by the manufacturer to operate, perform essential diagnostic verifications and calibration checks on the DataMaster. Mr. Barone is a Sustaining Member of College for DUI Defense. Mr. Barone is the principal and founding member of The Barone Defense Firm, whose practice is limited exclusively to defending drinking drivers. The Firm is headquartered in Birmingham, Michigan.

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