Ethyl Glucuronide (EtG) PEth Blood Alcohol Test – The EtG (ethyl glucuronide) test is commonly used to detect the presence of ethyl glucuronide, which is a direct metabolite of ethanol. Ethanol is the intoxicating chemical in alcohol. EtS (ethyl sulfate) is also metabolite of ethanol. PEth testing, is a highly reliable blood test allowing the detection of chronic excessive alcohol abuse over the previous 3-4 weeks.