Tox In Focus | Alcohol (EtG and EtS)

Tox In Focus

Focused Clinical Reference

Vol. 18 · Alcohol (EtG and EtS) · July 2026

Drug Quick Reference

Drug Class / Mechanism

Ethanol (CNS depressant)

Monitored via conjugated metabolites

Biomarkers

EtG (ethyl glucuronide)

EtS (ethyl sulfate)

Routes of Administration

Oral (beverages)

Incidental: sanitizers, mouthwash, foods

Commonly Detected With

Sedatives, opioids (potentiation)

Metabolism

Ethanol oxidized ~1 drink/hour

EtG/EtS: minor conjugated metabolites

Window of Detection

Ethanol ~8 to 12 h

EtG/EtS ~1 to 3 days

Control Status

Legal; monitored as a condition of treatment

ALCOHOL

EtG and EtS for abstinence monitoring, and the incidental-exposure traps

Monitoring alcohol abstinence by urinary ethanol alone is limited: ethanol clears in 8 to 12 hours and can be produced by fermentation of urinary glucose, especially in diabetes. Ethyl glucuronide (EtG) and ethyl sulfate (EtS), minor conjugated metabolites measured by LC-MS/MS, are not produced by fermentation and extend the detection window to 1 to 3 days.¹

Why This Matters Now

EtG and EtS are sensitive markers of recent drinking, but they are also produced by incidental exposure to alcohol in hand sanitizers, mouthwash, hygiene products, foods, and some medications. A 500 ng/mL cutoff reduces, but does not eliminate, incidental positives, and a single social drink can push EtG above 10,000 ng/mL the next day.²

⚠ An EtG or EtS positive confirms alcohol exposure, not necessarily drinking. Interpret levels with the cutoff, timing, and incidental sources before concluding a lapse.

Clinical Presentation

INTOXICATION

Sedation, disinhibition

Impaired coordination, slurred speech

Nausea, vomiting

Respiratory depression with other CNS depressants

Blackouts

WITHDRAWAL

Onset 6 to 24 h after last drink

Tremor, anxiety, agitation

Autonomic hyperactivity

Seizures

Delirium tremens (severe, can be fatal)

Important: Alcohol withdrawal can progress to seizures and delirium tremens, which are potentially fatal and require medical management; assess severity and treat promptly.

UDT Considerations

Urinary ethanol reflects only recent use (8 to 12 hours) and can result from post-collection fermentation, notably with urinary glucose in diabetes. EtG and EtS confirm alcohol exposure over 1 to 3 days and are not produced by fermentation; reading all three together, as summarized in the interpretation grid, separates recent use, older use, and fermentation.¹

Clinical Guidance

Use EtG and EtS, not urinary ethanol alone, for abstinence monitoring; ethanol clears quickly and can ferment.¹
Interpret EtG/EtS against the 500 ng/mL cutoff and known incidental sources (sanitizers, mouthwash, foods).²
Use the ethanol/EtG/EtS grid to distinguish recent use, older use, and fermentation.³
Consider incidental exposure when EtG is at or near the cutoff (typically under about 2,000 ng/mL).²
Do not estimate the amount consumed from EtG/EtS levels.

Point-of-Care Testing Availability

Available strips

Point-of-care and immunoassay ethanol tests detect only recent ethanol (~8 to 12 h).

Clinical use

Ethanol positives can arise from post-collection fermentation, especially in diabetes.

Limitations

LC-MS/MS EtG and EtS extend the window to 1 to 3 days and are not produced by fermentation.

ALCOHOL | Clinical & Program Guidance

Tox In Focus Vol. 18 · July 2026 · Page 2 of 2

Interpreting the Test Result

▲ If Testing Is Positive

Confirms exposure, not amount. EtG or EtS above cutoff shows alcohol exposure; levels cannot quantify intake.

Exposure is not proof of drinking. Sanitizers, mouthwash, foods, and medications can produce low positives near the cutoff.²

Use the grid for the pattern. Read ethanol, EtG, and EtS together (below) to place the result.

▼ If Testing Is Negative or Not Done

Abstinence within the window. Negative EtG and EtS suggest no use within about 1 to 3 days.

Timing and cutoff. Use outside the window, or below 500 ng/mL, may read negative.

Ethanol clears fast. A negative ethanol alone does not confirm abstinence; EtG and EtS extend the window.¹

Interpreting Ethanol, EtG, and EtS

Ethanol (IA)	EtG	EtS	Interpretation
Pos	Pos	Pos	Recent use, within ~12 h (unless post-collection fermentation).
Neg	Pos	Pos	Use more than 12 h before collection.
Neg	Neg	Pos	Older use; low levels can follow incidental exposure; cooking wine contains EtS.
Pos	Neg	Pos	Recent use (unless post-collection fermentation).
Pos	Neg	Neg	Post-collection fermentation, not alcohol use.
Neg	Pos	Neg	Possible bacterial EtG; alcohol use cannot be excluded.
Pos	Pos	Neg	Fermentation with bacterial contamination; or ~5% genetic EtG-only.

Fermentation of urinary glucose to ethanol can occur in diabetes or with improper storage. Cutoff 500 ng/mL for EtG and EtS.

Key References

Helander A, Beck O. Ethyl sulfate: a metabolite of ethanol in humans and a potential marker of acute alcohol intake. J Anal Toxicol. 2005;29:270-274.
Reisfield GM, et al. Ethyl glucuronide, ethyl sulfate, and ethanol in urine after sustained exposure to an ethanol-based hand sanitizer. J Anal Toxicol. 2011;35(2):85-91.
Substance Abuse and Mental Health Services Administration. The Role of Biomarkers in the Treatment of Alcohol Use Disorders. SAMHSA Advisory. 2012.

DISCLAIMER: This document is intended for clinical reference and educational purposes only. It does not constitute medical, legal, or professional advice and should not replace independent clinical or programmatic judgment. Content reflects published data available at time of preparation. ToxiPharm LLC makes no warranties regarding completeness or applicability in all settings. | © 2026 ToxiPharm LLC | toxipharm.org