Home
/
Markers
/
Drug Screening
/
Alcohol (EtG)

EtG test: detecting alcohol use in urine

An EtG test measures ethyl glucuronide in urine, a breakdown product your liver makes when you drink alcohol. The liver attaches a small share of the alcohol to glucuronic acid, a substance the body uses to send waste out through the kidneys.

Alcohol itself leaves your blood within a few hours, while ethyl glucuronide stays in your urine for days. You cannot feel whether it is still there; only a urine alcohol test can show it.

According to the laboratory guide of Slingeland Hospital, EtG in urine can be detected 40 to 130 hours after drinking, depending on how much was drunk. Zuivertest lets you order the test without a GP referral.

Doctor's Assessment Included

Alcohol (EtG): what this test measures

The EtG measurement counts how much ethyl glucuronide is in a urine sample, in micrograms per litre (µg/L). The laboratory compares that amount with a cut-off: the level above which a result counts as positive.

A positive result means alcohol most likely entered the body in the days before the sample was taken. A negative result means the amount stayed below that laboratory's cut-off. A negative result does not prove that no alcohol was ever drunk, only that none was detected within a window of a few days.

Urine can be concentrated or watery, depending on how much you drink. Some laboratories therefore also measure creatinine, a waste product from muscle that shows how concentrated the urine is, and report the ratio between EtG and creatinine.

You hand in the urine at a collection point of one of the independent, certified laboratories that Zuivertest works with. Those locations belong to the laboratories themselves.

Alcohol (EtG): why this value matters

EtG in urine looks much further back than a breath test or a blood alcohol measurement. A breath test only sees alcohol that is still in your body, which is usually a matter of hours.

That is why EtG is used to follow a period without alcohol. Examples are treatment for alcohol problems, agreements with an employer, or a personal decision to stop drinking. Testing a few times a week can show an unbroken stretch without alcohol.

The measurement is sensitive, and that has a downside. According to Slingeland Hospital, hand sanitiser and mouthwash containing alcohol can produce a positive result. Propanol and a breakdown product of the sleeping medicine chloral hydrate can do the same.

Certain bacteria can form EtG in urine when alcohol is also present, for example in people with diabetes. The reverse also happens: bacteria can break EtG down in the urine, so a result comes out too low.

For those reasons, the same hospital states that a single EtG result is not reliable enough for use in court. A result you order yourself from Zuivertest is also not a CBR (Dutch driving licence authority) examination and does not replace one.

Alcohol (EtG): how the blood test works

Referral: No GP referral needed. After the order we arrange the referral through ZorgDomein, within one business day; orders after 17:00 or at the weekend start on the next business day. ZorgDomein emails a barcode, and that barcode is what the draw site needs.
The draw: A blood draw from a vein in the arm, at a partner laboratory's draw site. No home kit, no finger prick.
Where: 650+ draw sites run by independent laboratories across the Netherlands. Draw sites

Alcohol (EtG): when is testing worthwhile?

An EtG test makes sense when you want to know, or show, that you have not drunk alcohol in the past few days. EtG stays detectable for roughly 40 to 130 hours, so one test covers a few days at most.

To show a longer period without alcohol, you need repeated tests. The moment of each sample decides which days before it are covered.

For heavy drinking over a longer time, a different marker looks further back: CDT in blood. The CDT test measures a form of transferrin, an iron-carrying protein that changes with prolonged heavy drinking.

Discuss a positive result, or any doubt about the outcome, with your GP or the professional treating you.

Alcohol (EtG): lifestyle and this value

An EtG result is easiest to judge when you avoid other sources of alcohol as much as possible in the days before the test. Hand sanitiser and mouthwash often contain alcohol, so choose an alcohol-free version where you can.

If you cannot avoid such products, write down what you used and when. Do the same for medicines, such as a sleeping medicine containing chloral hydrate. That information helps the doctor judge a positive result.

Drinking a lot of extra water just before the sample dilutes the urine. The amount of EtG per litre then comes out lower, but a creatinine measurement can reveal diluted urine. So drink the way you would on an ordinary day.

Alcohol (EtG): frequently asked questions

How long is alcohol visible in a urine test?

With an EtG test, alcohol in urine can be detected 40 to 130 hours after drinking, according to the laboratory guide of Slingeland Hospital. The exact window depends mainly on how much was drunk: after a single drink it is shorter than after an evening of heavy drinking. Alcohol itself leaves the body much sooner.

Can hand sanitiser or mouthwash cause a positive EtG test?

Yes, hand sanitiser and mouthwash containing alcohol can turn an EtG result positive. Propanol can also disturb the measurement. If you used such products in the days before the test, mention it when you hand in the sample. A doctor can then place a positive result more accurately.

What does a negative EtG test mean?

A negative EtG result means the urine held less ethyl glucuronide than the laboratory's cut-off at the moment of collection. That fits with no alcohol, or very little, in the days before. The result says nothing about drinking in an earlier period, because the window only covers a few days.

Does a Zuivertest EtG test count for the CBR or in court?

No, an EtG measurement you order yourself is not a CBR examination and does not replace one. If the CBR, the Dutch driving licence authority, requires an examination, follow its instructions. For court use, Slingeland Hospital states that a single EtG result is not reliable enough. The test is meant for checking your own alcohol use.

What is the difference between an EtG test and a CDT test?

EtG in urine shows whether alcohol was drunk in the past few days, while a CDT test in blood responds to heavy drinking over a longer time. EtG can also pick up light drinking from a few days ago. CDT only changes with substantial drinking over a longer stretch. The two tests therefore complement each other.

Is a pharmacy EtG rapid test the same as a laboratory test?

No, with a pharmacy EtG rapid test you read a line on a strip yourself at home. With Zuivertest, a certified laboratory analyses your urine sample and a BIG-registered doctor then assesses the result. A rapid test is quick and cheap, but no doctor looks at your result.