ETG Cutoff Levels Explained

You got a number back. Maybe it was 180 ng/mL. Maybe it was 620. And now you’re staring at it trying to figure out one thing: does this count as a positive?

Here’s the uncomfortable truth almost nobody explains clearly: that number, by itself, doesn’t tell you anything. What matters is the cutoff level — the line your specific program has drawn between “negative” and “positive.” Two people can produce the exact same lab result and walk away with opposite outcomes, simply because their programs use different cutoffs.

This guide breaks down exactly how ethyl glucuronide (EtG) cutoff levels work, why 100, 250, and 500 ng/mL are the numbers you’ll see most often, who actually decides which one applies to you, and what to do if your result lands in a gray zone.

What Is EtG, and Why Does It Matter?

Ethyl glucuronide is a direct metabolite of ethanol — a byproduct your liver produces whenever alcohol enters your system, whether from a drink, a food, or even certain hygiene products. Because EtG is specific to alcohol exposure and lingers in urine well after the alcohol itself has cleared, it’s become the go-to biomarker for detecting recent drinking, even days after the fact.

That’s also exactly what makes EtG controversial. Its sensitivity is a feature for programs trying to catch every instance of drinking — and a liability for anyone who used mouthwash the night before a test.

Many labs also test for ethyl sulfate (EtS), a second ethanol metabolite that behaves similarly to EtG but is far less prone to picking up incidental, non-beverage exposure. Where EtG alone leaves room for doubt, EtG paired with EtS starts to tell a clearer story.

What an EtG Cutoff Level Actually Is

An EtG cutoff is the concentration threshold, measured in nanograms per milliliter (ng/mL), that a lab or program uses to call a result positive or negative. Above the cutoff, it’s positive. Below it, it’s negative — regardless of whether trace EtG is technically present in the sample.

There’s no biological switch that flips at a certain number. The cutoff is a policy decision, not a scientific constant. That single fact explains almost every point of confusion people run into with EtG testing.

Programs set cutoffs by weighing two competing priorities:

Sensitivity — catching as much alcohol exposure as possible, including light or older drinking
Specificity — avoiding false positives triggered by non-beverage ethanol sources like sanitizer or mouthwash

A lower cutoff favors sensitivity. A higher cutoff favors specificity. Neither one is objectively “correct” — it depends entirely on what the program is trying to accomplish.

The Three Cutoffs You’ll Actually Encounter

Cutoff	Priority	Who Typically Uses It	False-Positive Risk	What It Catches
100 ng/mL	Maximum sensitivity (“zero tolerance”)	Strict-abstinence probation, some treatment programs, child custody cases	Higher — can flag incidental exposure	Any recent alcohol exposure, including light or several-day-old drinking
250 ng/mL	Balanced middle ground	General screening panels, some employers	Moderate	Moderate drinking, with fewer incidental flags than the 100 ng/mL line
500 ng/mL	Minimizing disputes	Widely referenced by the Substance Abuse and Mental Health Services Administration (SAMHSA); common for general employment screens	Low	Moderate-to-heavy recent drinking

A result somewhere between 100 and 500 ng/mL sits in what’s often described as a “very low positive” band. That range can plausibly reflect either light drinking or an entirely innocent exposure source, which is exactly why a single number, without the context of the cutoff and without confirmation testing, isn’t enough to draw a firm conclusion on its own.

Who Actually Sets Your Cutoff

Here’s the part almost no one tells you clearly: you don’t get to choose your cutoff, and neither does the lab acting alone. The number that applies to you comes from whichever of these set the policy:

Your court order or probation agreement
Your county or state supervision office
The laboratory your program contracts with
Your employer’s alcohol and drug policy
Your treatment program’s clinical protocol

There is no single national or universal EtG cutoff. Probation requirements, for instance, are known to vary not just state by state but county by county and even court by court, depending on which testing vendor a jurisdiction uses. SAMHSA’s advisory guidance recommends 500 ng/mL specifically to cut down on false positives from incidental exposure — but that’s a recommendation, not a mandate, and plenty of programs deliberately choose the more sensitive 100 ng/mL line because catching every instance of drinking is the whole point of their monitoring.

If you take one thing away from this section, make it this: get your exact cutoff number in writing. Ask your probation officer, HR contact, or program coordinator directly, and check your court order, testing agreement, or employee handbook. An average pulled from a random website will not match your actual paperwork — and it’s not something drinking water, timing, or exercise can change after the fact, either.

How the Testing Process Actually Works

Sample collection — usually an observed or semi-observed urine sample in legal or forensic settings.
Initial screening — an immunoassay test, sometimes a rapid point-of-care strip, checks the sample against the program’s chosen cutoff.
Confirmation testing — a positive screen is often sent for gas chromatography/mass spectrometry (GC/MS) analysis, the analytical gold standard.
EtS cross-check — some programs test EtS alongside EtG specifically to separate genuine drinking from incidental exposure.
Reporting — the lab returns a numeric ng/mL result along with a positive/negative call based on your program’s cutoff.

How Long Does EtG Actually Stay Detectable?

Detection time depends on how much alcohol was consumed and which cutoff is being applied. A lower cutoff extends the effective window because it’s picking up a much smaller residual amount of the metabolite.

At a 500 ng/mL cutoff: roughly 24–48 hours after moderate drinking
At a 250 ng/mL cutoff: roughly 36–60 hours
At a 100 ng/mL cutoff: potentially several days for heavy or repeated drinking

You’ve probably seen the claim that EtG can be detected for up to 80 hours after any drinking. That figure is real, but it’s the outer edge — typically only reached after heavy, sustained drinking measured against the most sensitive cutoff, not a typical result after a couple of drinks.

It’s also worth knowing that EtG itself clears the body fairly quickly, with a half-life of roughly two to three hours. What determines your detection window isn’t how slowly EtG breaks down — it’s how much was produced to begin with, and how sensitive the cutoff is that’s measuring it. This is also why EtG can confirm that drinking happened, but it can’t tell anyone how much was consumed or pinpoint the exact time of the last drink. Two people who drink very different amounts can land on surprisingly similar EtG numbers depending on hydration, metabolism, and liver function.

If you want a rough, personalized starting point based on your own drinking timeline, the EtG Calculator Hub lets you estimate where you’d likely fall against the 100, 250, and 500 ng/mL thresholds — though it’s still an estimate, not a substitute for knowing your program’s actual cutoff.

Incidental Exposure: The Part That Causes the Most Anxiety

Because EtG is so sensitive, everyday products containing trace ethanol can occasionally push a result above a low cutoff without anyone drinking a single beverage. The most commonly cited sources include:

Mouthwash and other oral hygiene products
Hand sanitizer, especially with frequent or heavy use
Vanilla extract and other alcohol-based cooking ingredients
Certain cough syrups and over-the-counter medications
Fermented foods, in rare high-exposure cases

Studies on incidental exposure have generally found that these sources can push results above 100 ng/mL, but they rarely push results above 500 ng/mL — which is precisely the reasoning behind SAMHSA’s recommended threshold. It’s also why programs that insist on the strict 100 ng/mL line for court-ordered abstinence tend to lean on EtS confirmation rather than acting on a screening result in isolation.

EtG vs. EtS: Why Confirmation Testing Matters

EtS follows a metabolic pathway similar to EtG but is much less susceptible to environmental contamination. Pairing the two gives labs a way to sanity-check a borderline call:

Positive EtG + positive EtS points more strongly toward actual alcohol consumption.
Positive EtG + negative or very low EtS raises the real possibility of incidental exposure rather than drinking.

Programs using the sensitive 100 ng/mL cutoff are the ones most likely to lean on this second layer, precisely because that cutoff is the most exposed to false positives in the first place.

Not All Monitoring Is Urine-Based

It’s also worth knowing that EtG cutoffs only apply to urine testing. Devices like SCRAM (Secure Continuous Remote Alcohol Monitor) work completely differently — measuring alcohol continuously through the skin rather than via a single sample — and are calibrated against their own separate standards, not the ng/mL thresholds discussed here. If you’re comparing a SCRAM reading to a urine EtG number, you’re comparing two different systems entirely.

Cutoffs by Setting

Probation and court-ordered monitoring. Courts frequently reference 500 ng/mL in judicial training materials, but abstinence-focused supervision — DUI/DWI conditions, child custody cases — often opts for the stricter 100 ng/mL line to enforce genuine zero tolerance. Confirm your exact number with your supervising officer or court order.

Workplace and occupational testing. Employers vary, but programs that prioritize legal defensibility over maximum sensitivity tend to lean toward the SAMHSA-aligned 500 ng/mL threshold to reduce disputes.

Addiction treatment programs. Programs requiring participants to demonstrate strict abstinence before advancing to a new phase of care often use 100 ng/mL, treating even low-level positives as clinically meaningful.

A Simple Framework for Figuring Out Your Cutoff

Identify who ordered the test. Court, probation officer, employer, or treatment program — each sets its own policy.
Check whether it’s written down. Court orders and probation agreements often state the cutoff explicitly.
Consider the program’s goal. Zero-tolerance programs skew toward 100 ng/mL; general screening skews toward 500 ng/mL.
Ask if EtS confirmation was used. If your result falls in the 100–500 ng/mL range and no EtS check was run, ask whether one is available before treating the result as final.
Think about documented exposure. Recent mouthwash, sanitizer, or medication use is worth disclosing before a test, not after a positive result.

Mistakes People Make With EtG Results

Assuming 500 ng/mL is universal. It’s a common recommendation, not a rule that applies everywhere.
Treating a positive as proof of a specific amount consumed. EtG confirms exposure, not quantity or exact timing.
Overlooking exposure sources before a low-cutoff test. Heavy sanitizer or mouthwash use in the day or two before testing can matter.
Trusting generic online charts as a legal guarantee. They’re educational estimates, not a substitute for your program’s actual policy.
Skipping the request for EtS confirmation on a disputed low-level positive, when it may be available.

FAQs

Is 100 ng/mL or 500 ng/mL the more common EtG cutoff? It depends entirely on the program. Courts often reference 500 ng/mL, but strict-abstinence conditions frequently specify 100 ng/mL instead. There’s no single default — check your paperwork.

Can mouthwash or hand sanitizer really cause a false positive? Yes, particularly at lower cutoffs. Heavy or repeated use of alcohol-based products can occasionally push a result above 100 ng/mL, though it rarely pushes a result above 500 ng/mL.

How long does alcohol stay detectable on an EtG test? Roughly 24–48 hours after moderate drinking at a 500 ng/mL cutoff, extending to several days for heavy drinking measured against a 100 ng/mL cutoff.

Does a positive EtG mean I was drunk at some point? No. It confirms alcohol was consumed at some point within the detection window — not impairment, blood alcohol level, or exact quantity.

How is an EtG test different from a breathalyzer? A breathalyzer measures active, in-the-moment alcohol and reflects current impairment. EtG is a urine metabolite that reveals past consumption long after both the alcohol and any intoxication have cleared.

Can I dispute a positive EtG result? Yes. Requesting EtS confirmation, documenting any incidental exposure, and confirming the exact cutoff your program used are the standard first steps.

Do all labs use the same cutoff? No. The cutoff is set by whoever ordered the test — court, employer, or treatment provider — in agreement with their lab. 100, 250, and 500 ng/mL are all in active use depending on the setting.

Can I influence or lower my own EtG cutoff? No. The cutoff is a program-level policy decision. Hydration, timing, or exercise won’t change how a lab interprets your result against that threshold.

Conclusion

The number on an EtG lab report only means something once you know the cutoff sitting behind it. If a test is coming up or a result is in dispute, the path forward is straightforward: get your program’s exact cutoff in writing, ask about EtS confirmation if your result falls in that gray 100–500 ng/mL zone, and disclose any incidental exposure before testing rather than explaining it after the fact. Understanding the system — not guessing at a number — is what actually protects you.

This article is for general educational purposes only and isn’t medical or legal advice. Always confirm your specific cutoff and testing requirements with the court, employer, or provider administering your test.