How EtG Tests Work
Tests for illegal drugs usually do not include testing for the presence of alcohol although for students under the age of 21, alcohol is an "illegal drug." A separate test is required because unlike illegal drugs, alcohol only stays in the body for a few hours after use. Ethyl glucuronide (EtG) is a metabolite of alcohol that remains present in the body for up to 6 days after alcohol consumption.
EtG tests are urine tests which determine whether alcohol was previously consumed. EtG tests do not measure the amount of alcohol that was ingested and do not determine the timeframe in which it was consumed. Any alcohol use by anyone under 21 years old is illegal and can be both dangerous and harmful to that youth's health. Determining higher cut-off levels for EtG reduces the likelihood of students testing positive for alcohol consumption due to innocent exposure from products like mouthwash which contain small amounts of alcohol.
Cut-off levels range between 100ng/ml and 1,000ng/ml. The more alcohol a person consumes, the longer alcohol metabolites are present in the body.