Although it varies between states, and even counties, there are standard measurements used for alcohol testing. The most common by far is the Ethylgucuronide (EtG) test, however. This measures EtG levels in urine which, being a direct metabolite of alcohol (ethanol), give a far more accurate picture of alcohol consumption or abstinence than the level of ethanol itself in the urine. Ethyl Sulfate (EtS) testing is also used in some departments, given EtS identification as a biomarker of ethanol. Using these two methods, ethanol intake can be detected up to 80 hours after consumption, and even long-term alcoholics will not show elevated levels of the metabolite after that period of detoxification. As with any test for drugs, however, there have been reported problems and consistent questioning of the procedure’s black and white nature of testing for exposure. Some have claimed that they have been wrongly accused of ethanol consumption after accidental exposure, given that ethanol is present in many day-to-day products, such as aftershave and disinfectant gel, which can be breathed in as a vapour. This is similar to the poppy seed and hemp seed controversies, which have previously shown persons to be testing positive for drugs such as morphine and marijuana despite them not having taken them recently. Concentration of the urine can also be a factor in EtG/EtS levels, and although higher levels of the biomarker are taken to mean, on the whole, that ethanol consumption has taken place, there is no fixed ‘bright line’ as such where a definitive positive result is returned. So unreliable has it been, that the Substance Abuse And Mental Health Services Administration (SAMHSA) recently issued an advisory that EtG/EtS should be used as a marker to launch an investigation into alcohol abuse, but not be used for a definitive conclusion on it.
