The latest and greatest advance in alcohol testing is coming your way! Ethyl glucuronide, or EtG, is a very minor metabolite of ethanol, measurable in the urine following alcohol consumption. Prior to the availability of EtG testing, urine ethanol testing was used, which remains in the body only 8-10 hours after alcohol consumption and can also be formed in a urine sample, in the presence of yeast and glucose, in transit to the testing lab. EtG offers the advantage of remaining in the body for up to 80 hours after alcohol has been consumed. It is a test for prior exposure to alcohol, but not a measure of impairment. And because EtG is only formed in the liver, it cannot arise as a product of fermentation in an otherwise "clean" specimen. In the words of one knowledgeable participant in a monitoring program, "You can drink a six-pack on Sunday night and test clean on Monday." EtG testing certainly seemed to be the solution, potentially putting alcohol testing in the same detection window as drug testing--days instead of hours. EtG testing is currently in widespread use in monitoring healthcare professionals in diversion programs. Participants with a history of alcohol and substance abuse are allowed to utilize their license while under strict monitoring provisions, including a "zero tolerance" alcohol abstinence policy. Other members of the populous may face EtG testing, anyone under "zero tolerance" alcohol abstinence agreements--school testing programs, methadone clinics, individuals receiving treatment for Hepatitis C, child custody disputes, chemical dependency treatment programs, drug courts, probation/parole monitoring, and pregnant women--have all been mentioned as potential target audiences. Currently working its way through the California legislature is AB 1832, which lays the groundwork for continuous alcohol monitoring programs for multiple offender DUI's. One of the program requirements is that the participant must achieve at least 60 continuous days of alcohol abstinence before release from the program, to be measured by either the SCRAM device or daily EtG urinalysis. Marketed as the "gold standard" for monitoring alcohol abstinence, EtG has now been commercially available for almost 2 years. While there are numerous claims of positive tests when alcohol consumption has been adamantly denied, the prevalence of the phenomenon is unknown due to the confidentiality surrounding the programs utilizing the testing. There are only two possible sources for the alcohol: exogenous and endogenous. Endogenous alcohol production is a documented phenomenon known as "auto-brewery syndrome". And while no one has been able to produce a positive EtG test attributable to endogenous alcohol production, its effect on EtG levels has never been studied scientifically. As for exogenous sources of alcohol, the ubiquitous nature of ethyl alcohol in our environment must certainly be considered. It is present in many hygiene products, foods, over-the-counter and prescription liquid medications and inhalers, gasoline fumes, and many non-CFC refrigerants...the sources seem endless. The question then becomes "Why isn’t everyone testing positive for EtG?" The most probable explanation lies in differences in metabolism. It is possible that some people produce a larger amount of EtG as a result of higher levels of the liver enzyme responsible for converting ethanol to ethyl glucuronide, a condition known as polymorphism. [By the way, there is no way to prove or disprove that a person has a polymorphism.] So the minute amount of alcohol present from unavoidable sources are actually causing those with this genetic predisposition to test over the cutoff level for a positive test. It has also been postulated that certain medications may be inducing this hyperproduction of EtG. It is known that acetaminophen (Tylenol) and ethinyl estradiol (an estrogen component in many birth control pills) are also metabolized by the same enzyme and are known to up-regulate, or induce, the enzyme system. The study most often cited as proof that there is 100% accuracy in EtG testing proving alcohol consumption involved a mere 35 forensic psychiatric patients in Germany. Another article summarizing the pre-marketing testing and studies done on EtG leads to one conclusion: If you consume alcohol, you will test positive for EtG. We know nothing about EtG when there is no alcohol consumption. Dr. Greg Skipper, who brought the test to the U.S. for commercialization, conducted his own study, testing the validity of EtG in determining alcohol relapse in his own program participants. While the results appear valid, the study involved a total of 12 subjects, all of whom were male. Interestingly, the vast majority of claimed false positive EtG's is comprised of women. A study published in February 2004 perhaps summarizes the problems with EtG testing the best. It concludes that alcohol-containing foods, including cakes and fruit juices, could cause low-level positive EtG tests and recommends further studies to determine appropriate cut-off values to overcome the potential of "false positive" results resulting from the test method’s high sensitivity. It also suggests further studies on individual glucuronidation (metabolic) rates, and the normalization of the EtG level to the creatinine concentration to account for variability in urine concentration. Has any of this been done? Absolutely not! Skipper readily admits that further studies are needed. "Particularly I agree that more extensive and valid research is needed to backup and/or refine date already obtained. I have been encouraging funding and a researcher interested in research from every organization that I know about that might do it." Research on EtG in the United States is curiously absent. While it seems that the laboratories that perform the testing should accept some of the responsibility for conducting such studies, they are currently under no legal pressure to do so. While SmithKline Beecham Corp. v. Doe (Texas 1995) established that labs have a legal duty to warn both employers and test subjects of any known legal substances such as foods and medications that may affect a drug test, it is both overly burdensome from an economic standpoint and virtually unworkable from a liability standpoint when it comes to actually defining the parameters of their duty to conduct such research. Meanwhile, the test continues to be used to nurses, doctors and pharmacists, among others, with sometimes devastating consequences, with an unknown rate of error. Was it the Pinot Noir, or was it the cream puff? The prediction of the future widespread use of EtG testing in the absence of further studies to determine appropriate cutoff levels is a frightening prospect. There is now a screening test available, bringing the cost down significantly. Skipper has made the following prediction: "I think EtG is going to be seen much more widely used. It's going to bring testing for alcohol use in parallel with opioid testing." "...We are advising Medical Review Officers that "incidental exposure" to alcohol can cause low level positives in some individuals. We still haven't clearly characterized the validity or possible source, if valid, of "false positive" EtG tests, except as mentioned..." says Skipper.