EtG testing comes up in California DUI cases in a very practical setting. Usually, the question is not whether you were driving under the influence on a new date. The question is whether a court, probation department, treatment program, licensing monitor, or custody evaluator believes you used alcohol when you were ordered not to.

I see EtG issues most often after a positive urine test during DUI probation, pretrial release, DUI court, drug court, or a professional monitoring program. The paperwork may call it an alcohol test, an abstinence test, a metabolite test, or simply a urine screen. Those words matter less than the actual method, cutoff, confirmation, and specimen validity findings. I am Joel Brand, and here is what an EtG result actually proves, what it does not, and what to do when one comes back positive.

What EtG Measures

EtG stands for ethyl glucuronide. It is a direct, non-oxidative minor metabolite of ethanol. In plain English, when ethanol enters the body, a small amount can be converted into EtG and then excreted, commonly in urine.

A positive EtG result means ethanol entered the body. It does not measure impairment. It does not measure blood alcohol concentration. It does not tell a judge whether you were safe to drive, how drunk you were, or whether you were above a legal BAC limit at any particular time.

That distinction gets lost. A person may hear "alcohol positive" and assume the result proves drinking in the ordinary sense. Sometimes it does. Sometimes it points to exposure that needs a closer look. Either way, EtG is a metabolite test, not a driving impairment test.

The most common EtG test in DUI monitoring is a urine test. Laboratories often pair EtG with EtS, which stands for ethyl sulfate. EtS is a companion alcohol metabolite. When both EtG and EtS are present in a pattern that fits drinking, the result is harder to explain away as a lab oddity. When EtG is positive and EtS is negative, that can point away from beverage alcohol use and deserves attention.

Hair and nail EtG testing also exist. Those tests are used less often in ordinary DUI probation, but they can appear in professional licensing, custody litigation, treatment monitoring, or after repeated urine testing problems. Hair and nail testing look at a longer window. That longer window can sound attractive to a monitoring program, but it also raises its own questions about timing, exposure, collection, and interpretation.

The "80 Hour" Claim

EtG is often marketed as an "80 hour" alcohol test. That phrase is repeated so often that people treat it like a rule. It is not a rule. It is the outer edge in some heavy drinking situations, not the ordinary expectation for every person after every drinking event.

For a typical single drinking episode, the practical urine EtG window is often closer to 24 to 48 hours. Some people clear faster. Some test positive longer. The detection window depends on dose, timing, the laboratory cutoff, hydration, kidney function, body size, and individual metabolism. A person who had a small exposure and is tested two days later is in a different position from a person who drank heavily and is tested the next morning.

This matters in court because vague statements are easy to overstate. "EtG can detect alcohol up to 80 hours" is not the same as "this result proves drinking within 80 hours." The number on the report, the cutoff used, and the rest of the specimen data are where the real discussion begins.

Cutoffs Matter

The word "positive" is not enough. Before conceding an EtG violation, I want to know the cutoff. Common laboratory cutoffs include 100, 500, and 1000 ng/mL. The same urine sample might be positive at 100 ng/mL and negative at 500 ng/mL.

A 100 ng/mL cutoff is sensitive. It can catch low-level exposure that a 500 ng/mL cutoff would not report as positive. That can include incidental exposure from products that contain alcohol. A 500 ng/mL cutoff is commonly used to reduce the risk of low incidental positives, though it does not eliminate every argument. A 1000 ng/mL cutoff is higher still, and may be used by some programs when the goal is to focus on stronger evidence of consumption.

Do not let anyone reduce the issue to "you were positive." Ask what cutoff was used. Ask whether the number reported is EtG only or EtG with EtS. Ask whether the result came from an initial screen or from confirmatory testing. The cutoff can change the meaning of the same report.

Who Gets Tested

EtG testing is not limited to one corner of the legal system. In California, it can appear anywhere abstinence is being monitored. That includes DUI probation with a no-alcohol condition, especially where the court has imposed alcohol terms under statutes such as Vehicle Code 23538. It can also appear as a condition of pretrial release while a DUI case is pending.

DUI court and drug court programs often use EtG because they monitor behavior closely and respond quickly to claimed violations. Treatment programs may use it to check compliance with program rules. Professional licensing boards and monitoring programs may use it for nurses, doctors, lawyers, pilots, and other licensed professionals whose paperwork requires abstinence or testing.

Family law cases can also involve EtG testing. In custody disputes, one parent may claim the other is drinking despite court orders or safety concerns. The EtG result then becomes part of a larger factual record, not a stand-alone answer to every question about parenting, judgment, or risk.

Incidental Exposure

Some low positive EtG results can come from alcohol exposure that is not drinking. That does not mean every positive is harmless. It means the source should be investigated before the report is treated as the end of the story.

  • Hand sanitizer, especially frequent use in medical, service, or childcare work.
  • Mouthwash and breath sprays that contain alcohol.
  • Cough syrup and other over-the-counter liquid medicines.
  • Kombucha and other fermented drinks.
  • Non-alcoholic or "alcohol removed" beer, which can still contain up to about 0.5 percent alcohol by volume.
  • Vanilla extract and other alcohol-based flavoring extracts.
  • Communion wine or other religious exposure.
  • Some fermented foods.
  • Workplace exposure to alcohol-based cleaning products, disinfectants, or solvents.

The timing matters. So does the amount, frequency, and documentation. A person who used hand sanitizer once is in a different position from a nurse who used it dozens of times during a shift. A person who drank several non-alcoholic beers without realizing they contained alcohol has a different record to build than a person who simply says, weeks later, "maybe it was something I ate."

If you are under an abstinence order, the safest practical habit is to avoid products that contain ethanol when you can. Read labels. Keep receipts. Take photos of bottles, ingredient lists, and workplace products when exposure is real. Documentation made at the time carries more weight than a memory reconstructed after a violation notice arrives.

Why Water Loading Backfires

There is a bad strategy that gets repeated online and in courthouse hallways: drink large amounts of water before an EtG test to flush the alcohol out. I am going to be direct. That plan often creates a worse problem.

Laboratories do not just test for EtG. They also check specimen validity. Creatinine, specific gravity, and pH are measured on every sample. Those values tell the lab whether the urine looks like real, normally concentrated human urine.

A creatinine under 20 mg/dL with a low specific gravity is commonly reported as diluted, or "dilute." Under about 2 mg/dL with water-like specific gravity is usually reported as substituted or invalid rather than merely dilute. That is a different category of problem, and it can be treated as an attempt to defeat the test.

In most California courts and monitoring programs, a dilute result is treated like a missed or failed test. It buys nothing. It often costs the same as a positive. Some programs do not care whether the dilution was intentional, accidental, or caused by panic. They care that the sample could not be relied on.

There is also a courtroom problem. A dilute sample looks like consciousness of guilt. It converts the argument from "what does this number mean" into "why did this person produce a suspicious sample." That credibility argument is much harder to win.

Water can lower concentration. In theory, it can push a real positive below a cutoff. But the dilution flags often fire first. Then the program may respond by ordering immediate observed retesting, increasing testing frequency, using hair or nail testing, or switching the person to a continuous transdermal device such as a SCRAM bracelet. That can be a worse outcome than dealing with the original urine result.

The honest advice is simple. Normal hydration is fine. Do not stop drinking water. Just do not load up. What actually helps is knowing your cutoff, documenting exposure sources, asking for confirmation testing, and preserving the records needed to evaluate the result.

What I Check After a Positive

When someone brings me an EtG positive, I do not start with panic and I do not start with excuses. I start with documents. The report itself is usually not enough.

I ask for the litigation packet or the laboratory packet. That should identify the test performed, the specimen validity results, the cutoff, the numerical result if one was reported, the confirmation method, and the chain of custody. If the first result was an immunoassay screen, I want to know whether it was confirmed by LC-MS/MS. Confirmation matters because screening tests are designed to be efficient, while confirmatory methods are designed to identify and quantify the target compounds with greater specificity.

I check whether EtS was run alongside EtG. EtG positive with EtS positive may fit drinking, depending on the numbers and facts. EtG positive with EtS negative points away from drinking and raises questions about degradation, contamination, timing, or the reliability of the interpretation. It does not automatically win anything, but it changes what should be asked.

I also check the chain of custody. Who collected the sample? Was it observed? Was the container sealed? When was it transported? When did the lab receive it? Were there delays? Were preservatives used? Was the sample stored properly? Chain of custody problems do not make every result disappear, but they matter when the government or monitoring program is asking a judge to rely on a lab report.

Then I look at the timeline. When was the alleged drinking? When was the test? What was the cutoff? Was there any known exposure to sanitizer, mouthwash, medication, kombucha, alcohol-removed beer, extracts, fermented foods, communion wine, cleaning products, or solvents? Was the exposure documented at the time? Were there witnesses, receipts, work schedules, treatment notes, or photographs?

The timing of documentation matters because courts are skeptical of after-the-fact explanations. If you used cough syrup the night before a test, take a photo of the bottle and the label. If your job requires heavy sanitizer use, preserve the schedule and the workplace product information. If you accidentally drank a beverage labeled "non-alcoholic," keep the can or receipt if possible. The goal is not to tell a dramatic story. The goal is to give the court something concrete to evaluate.

How Courts Usually See It

An EtG violation is usually a probation violation issue or a monitoring compliance issue. It is not a new criminal trial. That difference matters.

In a new DUI trial, the prosecution must prove the charge beyond a reasonable doubt. A probation violation is decided by a judge under a lower standard, usually preponderance of the evidence. That means the judge is deciding whether the violation more likely than not occurred. The rules and pressure points are different.

That lower standard is why the details matter early. A vague incidental exposure claim may not be enough. A lab report with a clear cutoff, confirmatory LC-MS/MS result, EtG and EtS consistency, and valid specimen markers may be treated very differently from a low EtG result at a 100 ng/mL cutoff, no EtS, a questionable collection record, and documented non-beverage exposure.

The practical question is not whether EtG science can be debated in the abstract. The question is what this result proves in this case, under this order, with this cutoff, this collection history, this confirmation method, and this person's documented facts.

If you are facing an EtG allegation, focus on the record. Get the lab packet, identify the cutoff, check the validity markers, look for EtS, document exposure sources, and avoid dilution games. In court, the fight is usually over reliability, context, and credibility.