What is EtG and how long can it be detected?

EtG (ethyl glucuronide) is a direct metabolite of ethanol produced in the liver. It appears in urine within 2 hours of drinking and can be detected for 24–80 hours after light to moderate drinking, and up to 120 hours after very heavy consumption. The detection window is much longer than blood alcohol concentration (BAC), which clears within 12–24 hours.

What are the EtG test cutoff levels?

EtG urine tests use different cutoff thresholds: 100 ng/mL, 200 ng/mL, or 500 ng/mL. The lower the cutoff, the more sensitive the test — and the longer it can detect alcohol use. A 100 ng/mL cutoff can detect drinking that occurred 3–4 days ago in some cases, which is why it has been criticized for false positives from incidental exposure (mouthwash, hand sanitizer).

Can EtG give a false positive?

Yes. EtG can be detected after incidental alcohol exposure from: alcohol-based mouthwash (especially with high-frequency use), some cough syrups, hand sanitizer contact (though absorption is minimal), and certain foods prepared with alcohol. The 500 ng/mL cutoff is generally recommended to reduce false positives from incidental exposure.

Is EtG detection affected by body weight?

Body weight affects alcohol metabolism rate and peak BAC, which indirectly affects EtG production and duration. Heavier individuals generally metabolize alcohol faster, but EtG detection windows are primarily driven by total alcohol consumed rather than body weight. Individual metabolic rates, liver health, and hydration also play significant roles.

How is EtG different from a BAC test?

A BAC (blood alcohol concentration) test measures the current level of alcohol in the bloodstream. It becomes negative within 12–24 hours after drinking stops. EtG is a metabolic byproduct that persists much longer — up to 80–120 hours. BAC is used to detect current impairment; EtG is used to detect recent alcohol use in sobriety monitoring and workplace testing.

Can ETG be detected from hand sanitizer or mouthwash use?

Yes — incidental alcohol exposure can produce positive EtG results, particularly at the sensitive 100 ng/mL cutoff. Studies have shown that regular use of alcohol-based mouthwash (e.g., Listerine) can produce EtG levels up to 800 ng/mL in some individuals. Hand sanitizer produces much lower levels through skin absorption — generally below 100 ng/mL. For this reason, the Society of Forensic Toxicologists recommends using a 500 ng/mL cutoff in sobriety monitoring programs to distinguish incidental exposure from intentional drinking.

Does drinking water or exercising help clear EtG faster?

Hydration increases urine output and may dilute EtG levels in urine, potentially reducing the concentration measured on a test — but it does not speed up the actual metabolic elimination of EtG from the body. Similarly, exercise does not accelerate EtG clearance. The only factor that meaningfully reduces EtG detection time is the total amount consumed. Some testing programs use creatinine levels to detect specimen dilution, which can flag a sample as invalid if creatinine is too low, making dilution an unreliable strategy.

EtG Calculator — Alcohol Detection Window

Estimates EtG urine detection window and peak BAC from drinks consumed, time elapsed, and body weight — with test cutoff guidance.

What Is EtG Testing?

This EtG calculator estimates your urine EtG detection window based on the number of drinks consumed, hours elapsed since drinking, and body weight. Ethyl glucuronide (EtG) is a minor metabolite of ethanol — unlike ethanol itself (undetectable within 12–24 hours), EtG can be detected for significantly longer and is widely used in sobriety monitoring, workplace drug screening, and DUI probation contexts.

The detection window depends on how much was consumed: light drinking (1–3 standard drinks) produces detectable EtG for roughly 24–48 hours, while very heavy drinking (12+ drinks) can leave detectable EtG for up to 80–120 hours at sensitive cutoff levels.

How EtG Detection Windows Are Estimated

This calculator uses published research data to estimate EtG detection windows based on the number of standard drinks consumed:

1–3 drinks (light): 24–48 hours
4–6 drinks (moderate): 48–72 hours
7–11 drinks (heavy): 72–96 hours
12+ drinks (very heavy): 80–120 hours

These are population averages. Individual variation in metabolism, hydration, kidney function, and body composition can extend or shorten the window by 20–30%.

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EtG Cutoff Levels Explained

Labs can set different cutoff thresholds for reporting a positive EtG result. The most common cutoffs are:

100 ng/mL: Most sensitive — can detect very light drinking or incidental exposure. Higher risk of false positives.
200 ng/mL: Moderate sensitivity — common in clinical monitoring programs.
500 ng/mL: Least sensitive for remote drinking, reduces false positives from incidental alcohol exposure (mouthwash, hand sanitizer).

BAC vs. EtG: Key Differences

Blood Alcohol Concentration (BAC) tests detect current impairment. The legal limit for driving in the US is 0.08% BAC. BAC drops at approximately 0.015% per hour in a healthy adult. This means a person who peaks at 0.12% BAC is typically back to 0.00% in about 8 hours. EtG, by contrast, continues to accumulate and is excreted over days — making it useful for detecting drinking that occurred well after the alcohol itself has cleared. The ABV calculator can help estimate alcohol content of different beverages.

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Important Limitations of This Calculator

EtG detection windows vary considerably between individuals. This tool provides estimates based on population averages. Factors that can extend detection include: slow metabolism, dehydration, kidney dysfunction, and higher body fat percentage (alcohol is less soluble in fat). Factors that shorten detection include: rapid metabolism, high fluid intake, and high physical activity. This calculator should not be used to predict whether a specific test will return positive or negative. For concerns about alcohol use or testing, consult a healthcare provider or use our sobriety calculator.

EtG in Hair and Other Specimens

EtG can be detected in multiple specimen types beyond urine. Hair EtG testing can detect chronic alcohol use going back 3–6 months, with a cutoff of 30 pg/mg for heavy drinking (defined as >60 g alcohol/day). Hair testing is used to distinguish social drinking from heavy or chronic drinking in legal and clinical contexts. Blood EtG has a shorter detection window than urine (24–48 hours) and is less commonly used. Meconium (newborn stool) testing for EtG is used to detect prenatal alcohol exposure in the last trimester of pregnancy.

EtS (Ethyl Sulfate): A Companion Biomarker

EtS (ethyl sulfate) is another direct ethanol metabolite often measured alongside EtG. EtS has a similar detection window and is less susceptible to false positives from incidental exposure — because non-beverage sources of ethanol (mouthwash, certain foods) tend to produce higher EtG-to-EtS ratios than beverage alcohol does. Testing for both EtG and EtS, and examining the ratio, helps forensic toxicologists and clinical programs distinguish genuine alcohol consumption from environmental or accidental exposure. Most certified labs now report both values together.

Sources & References

Ethyl Glucuronide as a Biomarker of Alcohol Use — Substance Abuse and Mental Health Services Administration
Alcohol Use Disorder Biomarkers — National Institute on Alcohol Abuse and Alcoholism
Urine Ethanol and EtG Testing in Clinical Practice — American Association for Clinical Chemistry

EtG Calculator

EtG Detection Window Calculator