Ethyl Glucuronide (EtG) Alcohol Testing: Frequently Asked Questions

Redwood Toxicology Laboratory conducts a variety of lab tests to detect chemical dependency or substance abuse. One test looks for the presence of Ethyl glucuronide (EtG), a direct byproduct of beverage alcohol (ethanol) that is present in urine up to 80 hours following exposure to alcohol. Its presence in urine may be used to detect recent alcohol consumption, even after ethanol is no longer measurable. According to this document, "the presence of EtG in urine is a definitive indicator that alcohol was ingested."

However, in September 2006 the Substance Abuse and Mental Health Services Administration (SAMHSA) warned that the EtG test in determining abstinence lacks sufficient proven specificity, it is inappropriate to use a test result as primary or sole evidence that an individual prohibited from drinking, in a criminal justice or a regulatory compliance context, has truly been drinking. Therefore, legal or disciplinary action based solely on a positive EtG, or other test is inappropriate and scientifically unsupportable at this time. SAMHSA advises that these tests should currently be considered as potential valuable clinical tools, but their use in forensic settings is premature.