What Are ETG Cutoff Levels?
An ETG cutoff level is the concentration threshold that determines whether your test result is positive or negative. If your ETG level is above the cutoff, you fail. If it's below, you pass.
Here's the key point most people miss: the same ETG level can mean pass or fail depending on which cutoff your test uses.
- 500 ng/mL is the standard cutoff for most employment and DOT tests
- 100 ng/mL is the strict cutoff for probation and court-ordered monitoring
- 50 ng/mL exists but is rare (research settings only)
- Your result depends on BOTH your ETG level AND the cutoff used
The Three Main Cutoff Levels
500 ng/mL — Standard Cutoff
This is the most common cutoff level, used by the majority of testing programs.
Who uses it:
- Department of Transportation (DOT) regulated testing
- Most pre-employment screenings
- Standard workplace drug testing programs
- Many healthcare employer programs
Detection window: Approximately 24-48 hours after moderate drinking (2-4 drinks).
Why this level: The 500 ng/mL threshold balances detection sensitivity with practicality. It's high enough to avoid most false positives from incidental exposure (like hand sanitizer or mouthwash) while still detecting recent drinking.
100 ng/mL — Strict Cutoff
This stricter threshold is designed for zero-tolerance monitoring situations.
Who uses it:
- Probation and parole programs
- Court-ordered alcohol monitoring
- DUI/DWI monitoring programs
- Treatment and recovery programs
- Some child custody cases
Detection window: Approximately 48-80+ hours, depending on consumption amount.
Why this level: Programs using 100 ng/mL want maximum sensitivity. They're monitoring people who should not be drinking at all, so any alcohol consumption—even moderate—needs to be detected.
Important: If you're on probation or court-ordered monitoring, assume your test uses 100 ng/mL unless told otherwise. This threshold is 5× more sensitive than the standard cutoff.
50 ng/mL — Research/Specialty Cutoff
This is the most sensitive threshold, rarely used outside specialized settings.
Who uses it:
- Research studies on alcohol metabolism
- Some military testing programs
- Specialized forensic testing
Detection window: Can extend beyond 80 hours for heavy drinking.
Why this level: Maximum sensitivity for research purposes. At this threshold, even minor incidental exposure might trigger a positive result.
Quick Comparison
| Cutoff Level | Common Uses | Detection Window | False Positive Risk |
|---|---|---|---|
500 ng/mLStandard | Employment, DOT | 24-48 hours | Lower |
100 ng/mLStrict | Probation, Court | 48-80+ hours | Moderate |
50 ng/mLSevere | Research | 80+ hours | Higher |
Employment, DOT
24-48 hours
Lower
Probation, Court
48-80+ hours
Moderate
Research
80+ hours
Higher
* Detection windows are estimates for moderate drinking (3-4 standard drinks). Heavy drinking extends all windows significantly.
Check Your Current Level
Use our calculator to estimate your current ETG level and see how it compares to different cutoffs:
Quick ETG Check
Instant estimation (No data saved)
High Probability of Detection
Estimated 10 more hours until low risk (<100ng/mL).
*This is an estimation only. Individual results vary. Not legal or medical advice.
How to Find Out Your Cutoff Level
Not sure which cutoff applies to you? Follow these steps:
Step 1: Ask directly. Contact your testing administrator—probation officer, HR department, or program coordinator. Ask specifically: "What is the ETG cutoff level for my test?"
Step 2: Review your documentation. Check your testing agreement, court order, employment policy, or program handbook. The cutoff may be specified in writing.
Step 3: Know the defaults. If you can't get a direct answer:
- DOT-regulated tests → 500 ng/mL (federal standard)
- Probation/court → Usually 100 ng/mL
- Employment → Usually 500 ng/mL
Step 4: When in doubt, assume strict. If you cannot confirm your cutoff, plan for the 100 ng/mL standard. Being conservative is safer than being wrong.
Why Different Cutoffs Exist
Balancing Sensitivity and Specificity
Every drug test faces a tradeoff:
- More sensitive (lower cutoff) → Catches more true positives, but also more false positives
- Less sensitive (higher cutoff) → Fewer false positives, but might miss some true positives
The 500 ng/mL cutoff was chosen because it reliably detects intentional drinking while avoiding most false positives from incidental exposure.
Incidental Exposure Concerns
ETG can be detected from sources other than drinking:
- Hand sanitizers (alcohol-based)
- Some mouthwashes
- Certain foods (ripe fruit, vinegar-based sauces)
- Some medications
At 500 ng/mL, these typically don't cause positive results. At 100 ng/mL, heavy use of alcohol-containing products might. At 50 ng/mL, even normal use could potentially cause issues.
Regulatory Standards
DOT (Department of Transportation): Federal regulations specify 500 ng/mL for safety-sensitive transportation workers.
SAMHSA Guidelines: The Substance Abuse and Mental Health Services Administration provides testing guidelines, though individual programs can set stricter standards.
State Variations: Some states have specific requirements for probation testing, which may differ from federal standards.
What Affects Your Risk Level
Your ETG level depends on multiple factors beyond just time since drinking:
Factors that increase detection risk:
- Drinking larger amounts
- Drinking over extended periods (binge vs. single drink)
- Slower metabolism (age, liver health)
- Dehydration at test time
Factors that decrease detection risk:
- Smaller amounts consumed
- Faster metabolism
- Proper hydration
- More time elapsed
For a complete breakdown, see our guide on factors affecting ETG levels.
Related Resources
- ETG Calculator — Estimate your current ETG level
- ETG Detection Time Chart — Visual reference for detection windows
- Understanding the ETG Chart — How to read the chart
- ETG Calculation Formula — The math behind the estimates
500 ng/mL is the most widely used cutoff, particularly for employment and DOT-regulated testing. However, probation and court-ordered monitoring typically use the stricter 100 ng/mL cutoff. Always verify which cutoff applies to your specific test.
Most probation programs use 100 ng/mL, which is 5× more sensitive than the standard 500 ng/mL cutoff. This stricter threshold is designed for zero-tolerance monitoring situations where any drinking is prohibited. However, programs vary—ask your probation officer to confirm.
Generally, no. The testing program—not you—determines which cutoff to use. DOT tests must use 500 ng/mL by federal law. Court-ordered tests follow whatever the court specified. You cannot negotiate the threshold.
Being at or near your cutoff is risky. Lab testing has inherent variability (typically ±10-20%), and your actual ETG level fluctuates based on hydration. If the calculator shows 450 ng/mL and your cutoff is 500 ng/mL, you're not necessarily safe. Aim to be well below your cutoff.
Regular mouthwash use is unlikely to cause a positive at 500 ng/mL in healthy individuals. However, heavy or prolonged use of alcohol-containing mouthwash could potentially trigger positives at the 100 ng/mL cutoff. If you're being tested at the stricter level, consider alcohol-free alternatives.
This depends heavily on how much you drank. After 3-4 standard drinks, most people drop below 100 ng/mL within 48-72 hours. After heavy drinking (8+ drinks), it could take 80+ hours. Use our ETG calculator for a personalized estimate based on your specific situation.
Certified labs use two-step testing: an initial screen (immunoassay) followed by a confirmation test (LC-MS/MS) if positive. False positives on confirmed tests are rare but not impossible. If you believe your result is wrong, you can request a retest of the same sample.
Only if your test uses the 500 ng/mL cutoff. The same ETG level that passes one test might fail another. For example, 300 ng/mL would pass a standard employment test (500 cutoff) but fail a probation test (100 cutoff). Always know which cutoff applies to YOUR test.
This page is for educational purposes only. It does not constitute medical or legal advice. Individual results vary significantly based on metabolism, health factors, and testing conditions. The information provided should not be used as a guarantee of test results. Consult your testing administrator for specific cutoff levels and a healthcare provider or legal professional for guidance specific to your situation.