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Alcohol Testing: The Ultimate Guide to EtG Testing

Last Updated: March 18, 2024

Reviewed by Michael Espelin APRN

The history of blood alcohol testing dates back to the 1930s when the first blood alcohol content (BAC) tester was invented and trivially named the “drunkometer.” Other more efficient BAC tests began to spring up, providing aid to local authorities and medical facilities.

The BAC test began to make its way into various industries, including recruitment and employee behavioral assessment requirements. Some safety-sensitive employers, especially in an industrial setting, mandate frequent drugs, and blood alcohol level testing to ensure that employees are fit for work activities. This test is also practical in obtaining a driver’s license, operating heavy machines, mass transit industries, and other sensitive placements. Why is BAC so important?

Alcohol Testing Overview

According to the survey in 2018 by the National Survey on Drugs Use and Health (NSDUH), at least 86.3% of individuals within the age range of 18 and above reported having used alcoholic drinks at some stage in life, while about 70% of the population admitted to engaging in liquor drinks in the previous year. Furthermore, an estimated 26% to 45% of individuals aged 18 and older admittedly engaged in binge drinking bouts in the previous month.

Alcohol Use Disorder (AUD) in the United States

Moreover, this substance is by far the most commonly used addictive substance in the United States, with approximately one in every 12 adults abusing or addicted to alcohol.

The Markers Usually Checked for are:

  • abstinence
  • Recent use (by hours/days)
  • Social drinking
  • Binge drinking
  • Excessive drinking

Alcohol Testing is Largely Used in Situations such as:

  • Pre-employment requirement
  • Workplace screening program
  • Alcohol-related crime screening
  • Individuals granted visitation or child custody by the court
  • Drivers with a history of alcohol-related offenіes who are on probation

The tests show the concentration level and possible intoxication based on the BAC level. The BAC level is one of the most viable determinants for the recent use of alcohol, even though numerous other tests are conducted using various bodily samples.

Here are Some Alcohol Test Samples and What They Show:

  • Head hair concentration: For abstinence, social drinking, drunk, and abuse
  • Body hair concentration: for abstinence, intoxication, social drinking
  • Fingernail testing: for social drinking and abuse
  • Breath test: for intoxication and as long as required
  • BAC test: for abuse, drunk, social drinking, abstinence

Blood Alcohol Level: BAC Explained

There are different levels of effects and measurements for them. An individual with a BAC of .10% means that the person’s blood composition contains one portion of liquor drink to every 1000 portions of blood. In certain parts of the US, a person is said to be intoxicated at a blood alcohol level of .8%.Scientist holds a blood probe.

Various Factors May Influence the BAC of a Person; They Include:

  • Body weight
  • Use of medications
  • Water composition
  • Presence of food in the system
  • Number of drinks
  • Enzyme production
  • Time taken to consume the drink
  • Gender at birth and hormone level

The effects of alcohol at different levels or concentrations may differ from one person to another; however, when it comes to individual BAC and its physical and mental effects, the result can be organized in percentage progression.

BAC Level Effects
0.01-0.03 minimal effect, mood elevation
0.04 – 0.06 feeling relaxed, slightly impaired reasoning
0.07 – 0.09 mildly impaired balance, slight intoxication
0.10 – 0.12 significantly impaired movement and reasoning, slightly slurred speech
0.13 – 0.15 highly impaired motor control, loss of balance, anxiety, and restlessness
0.16 – 0.20 high dysphoria, nausea, and extremely drunk
0.25 – 0.30 critical intoxication, requires assistance for mobility, dysphoria, nausea, confusion, and vomiting
0.35 – 0.40 individual loses consciousness
0.40 above coma, respiratory failure, possible death

Key Facts About BAC and Alcohol Effects:

  • Concentration and effects are greatly affected by body mass. Bigger individuals have more room for the circulation of alcohol.
  • Males generally have more tolerance than females. This is because men are largely bigger, have lesser body fat and higher water content than women.
  • Alcohol-containing drinks used concomitantly with medications such as depressants may be dangerous to health as it is also a depressant and would increase intoxication.
  • Food in the system significantly slows down alcohol ethanol absorption into the bloodstream reducing its metabolism.
  • The absorption of ethanol into the bloodstream can be reduced by mixing with water or juice.
  • Activities such as exercises, cold showers, coffee, and others will keep you alert but will not affect your BAC. The body slowly reduces BAC over time.
  • The BAC of a person may continue to rise even after the bout of drinking is over. This is because of the ethanol storageб which is slowly absorbed into the bloodstream.

When is Alcohol Test Required?

Alcohol testing can be required where someone is suspected of consuming alcoholic drinks under circumstances where the use is prohibited. An alcohol test is usually requested by authorities when an individual displays one or more of the following characteristics:

  • Slurred speech
  • Poor judgment
  • Risky behaviors
  • Misconduct
  • Mood changes
  • Slurred speech
  • Nausea and vomiting
  • Slowed reflexes
  • Loss of coordination

In testing for alcohol, the ETG alcohol test is one of the most reliable detection tests because of its accuracy and versatility for all body samples such as hair tests, urine tests, BAC tests, etc. Specific Situations that Require the ETG Test are:

  • Court Cases: in situations such as child custody cases, a guardian may be obligated to take an ETG test to show that they are fit to cater to the child in their custody.
  • DUI and DWI program: driving under the influence or driving while intoxicated is an offense, and to ascertain the level of intoxication, an alcohol test is usually conducted.
  • Liver Transplant: The liver is responsible for alcohol metabolism. It is a strict requirement that the patient undergoes a liver transplant abstains from alcoholic drinks before and after the operation to avoid putting pressure on the liver as this may affect overall health.
  • Schools and Military: To avoid misconduct and enforce discipline, some schools and military barracks conduct compulsory tests.
  • Alcoholics Rehabilitation Facilities: A rehab facility is a treatment center for alcoholism, and patients may be tested occasionally to certify that they are dedicated to the treatment and maintaining sobriety.
  • Professional careers (airline pilot, medical practitioners, attorneys): careers that require handling highly technical equipment, automobiles, or human lives require compulsory alcohol tests to certify that the professional is physically and mentally fit to handle the task.

Types of Alcohol Testing

There are a few types of alcohol testing, and they are all effective; however, due to the time taken to conduct these tests and get a quick, accurate result, three of these tests are most commonly used.Woman takes the Breath Test. for alcohol

The common alcohol testing methods are:

  • Blood tests – which can detect alcoholic drinks used within the past 24 hours. This is conducted in a laboratory by qualified professionals
  • Saliva tests – which can detect the presence of the substance in the saliva for approximately 10 to 24 hours
  • Breath tests – which measure the amount of alcohol in the body via a breathalyzer device

Below we’ll review the tests which are considered to be the best in each category (blood, saliva, digital), ranked by our trained, paid staff.

ETG Testing

EtG testing has recently emerged as the most desired form of drug testing. EtG stands for Ethyl Glucuronide or simply ethanol, which is the intoxicating ingredient found in beer, wine, and liquor. EtG is produced when yeast, starches, and sugars are fermented. Upon entering the body, ethanol can severely impact decision making depending on the amount taken, the time since a person last drank, and their body weight. EtG is a urine testing process that tries to detect the presence of ethanol, which is a definitive indicator that the body has metabolized ethanol within the past three or four days. When ETG testing is used, alcoholic drinks can be detected in urine up to 80 hours after the last consumption of alcohol.

One of the earliest discoveries of the kinetics of ETG detection in the blood serum was on a human in 1997. The researcher discovered that ETG levels declined periodically at a half-life of 2 to 3 hours, and testing for ETG may not be viable after 6 to 18 hours or more.

ETG is administered to detect whether a person is consuming alcoholic drinks or not by using an immunoassay screen with Liquid chromatography–mass spectrometry (LC/MS) confirmation of any positives that might be a sign of alcoholic drinks use. Most labs will do confirmatory testing in conjunction with ETG testing to eliminate the possibility of a fake positive. Although it’s becoming quickly popular because of the longer detection window and accuracy, ETG doesn’t show the exact amount of drinks consumed.ETG test and urine can.

ETG Has Emerged as the Test of Choice for Alcohol Because of Several Benefits it Offers Over Other Options:

  • It’s more accurate than standard testing.
  • It has a considerably longer detection window than standard testing i.e., can detect the substance use up to 80 hours. In other words, it can detect ethanol even after other tests will fail to do so.
  • The biggest benefit of EtG testing is that it doesn’t give false-positives in the case of fermentation and only gives a positive result when alcoholic drinks are consumed.
  • It can be used on a urine specimen to test the abuse of other drugs in addition to alcohol.
  • It is ideal in scenarios of zero tolerance, such as when ordered by the justice system.

In addition to EtG, several other testing methods are also available to find out whether a person has used it or not.

Detection Time of ETG Alcohol Test

Etg is sensitive and can detect the metabolites long after use. It can detect the substance in urine for as much as five days after use.

Test Accuracy

The ETG test, however, has a few limitations that may alter its accuracy. The ETG test can show a positive result for exposure to any home or environmental product that contain a certain percentage of ethanol or ethyl alcohol; such products may include:

  • Cleaning reagents
  • Aftershave
  • Sanitizers
  • Mouthwash
  • Hair dyes
  • Food prepared with alcohol-based preservatives
  • Breath sprays

Blood Test for Alcohol

The best thing about a blood test is that it can measure the amount of ethanol in the system. Just like nicotine, it is also absorbed by the bloodstream. Although it reaches the highest level after one hour of drinking, it is detectable via a blood test within minutes of consumption. Blood tests are performed by qualified health professionals in a laboratory with specialized equipment.

Detection Time

A blood test can detect the use within the past 12-24 hours of use. This result may vary from one person to the other.

Test Accuracy

When it comes to the blood test, time is of the essence. The test is only viable within 6-12 hours after the person’s last drink.

Saliva Test for Alcohol

Saliva drug tests are very easy to administer and less invasive than the blood or hair follicle test. Moreover, the saliva test can detect both the drug and its metabolites. Collecting saliva is very easy. A cotton swab is usually placed inside the cheek, which can be used to detect the substance’s concentration in saliva, similar to how BAC can be detected in the blood. Because alcohol-containing drinks and their metabolites don’t stay in saliva for as long as they do in blood or urine, saliva has a short detection window. However, it offers a fast and straightforward method for detecting recent use.Doctor using a swab to take a saliva sample.

 

Detection Time

The substance can be detected in saliva for approximately 12 to 24 hours after ingestion, after which it will be metabolized and will no longer be detectable, at least in saliva.

Test Accuracy

Saliva alcohol tests can be conducted with a test strip. The results are fast and reliable; however, the test must be conducted within the frame of 12-24 hours of use, while the metabolites are still present in the saliva.

Breath Alcohol Test

A breath test detects the level of alcohol in the blood by determining the amount in the breath. The device used for estimating blood alcohol content by breath is known as a breathalyzer. Although it’s also the name of a brand, the term is generically used to refer to any device for estimating BAC through the breath.

The donor blows directly into the breathalyzer, which instead of measuring BAC in blood, estimates BAC indirectly by measuring the amount in the breath. 90% of alcohol is broken down by the liver, while the rest is blown out through breath or secreted with urine.

Detection Time

The substance may be detected in breath by using a device called the breathalyzer over a period of 24 hours.

Test Accuracy

The breathalyzer isn’t always accurate; there are a few factors that may alter the result, for example, mouthwash, breath fresheners, and other substances that may contain a small percentage of ethanol.

What Do The Alcohol Test Results Mean?

To interpret ETG test results, there are 3 specific categories of positive and then negative. While we all understand that the negative means complete abstinence, the positive result has various indications and detailing that is vital for decision making.

The Following are the Three “Positives” of the ETG Test and What They Indicate:

  • The High Positive: usually around >1000ng/mL, may indicate light or heavy drinking on the day of the test or the day before.
  • Low Positive: around 500 – 1000ng/mL. It means:
    • Light drinking within 24 hours
    • Intense drinking within one to three days before the test
    • Exposure to household alcohol-based products within the past 24 hours
  • Very Low Positive: about 100 to 500ng/mL, this indicates:
    • Recent exposure to alcohol-based home products
    • A bit of light drinking within 12-36 hours
    • Heavy drinking within one 1-3 days

ETG and other tests are considered very useful, and though unequally efficient, they have a reasonable error margin that can be managed. ETG is suited for daily drinking screening rather than complete abstinence tests to ensure accuracy.


Page Sources

  1. National Institute on Alcohol Abuse and Alcoholism, Alcohol Facts and Statistics, http://pubs.niaaa.nih.gov/publications/AlcoholFacts&Stats/AlcoholFacts&Stats.pdf
  2. U.S. National Library of Medicine, Blood Alcohol Level, https://medlineplus.gov/lab-tests/blood-alcohol-level/
  3. College of Saint Benedict & Saint John's University, Understanding Blood Alcohol Content (BAC), https://www.csbsju.edu/chp/health-promotion/alcohol-guide/understanding-blood-alcohol-content-(bac)
  4. Stanford University, What Is BAC?, https://alcohol.stanford.edu/alcohol-drug-info/buzz-buzz/what-bac
  5. Mark H. Wojcik, Jeffrey S. Hawthorne, Sensitivity of commercial ethyl glucuronide (ETG) testing in screening for alcohol abstinence, 2007, https://academic.oup.com/alcalc/article/42/4/317/160166
  6. Michael G. McDonell, Jordan Skalisky, Emily Leickly, Sterling McPherson, Samuel Battalio, Jenny R. Nepom, Debra Srebnik, John Roll, Richard K. Ries, Using Ethyl Glucuronide in Urine to Detect Light and Heavy Drinking in Alcohol Dependent Outpatients, 2015, https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4663163/
  7. Medical University of South Carolina, About Urine Ethylglucuronide (EtG) Testing, https://medicine.musc.edu/departments/psychiatry/divisions-and-programs/programs/cnl/heavy-alcohol-testing/etg

Published on: August 2nd, 2016

Updated on: March 18th, 2024

About Author

Peter J. Grinspoon, MD

Dr. Peter Grinspoon is an experienced physician with long-term clinical practice experience. As a former analgesic addict, Dr. Grinspoon knows precisely how important it is to provide patients with effective treatment and support. Medical writing for him is the way to communicate with people and inform them about their health.

Medically Reviewed by

Michael Espelin APRN

8 years of nursing experience in wide variety of behavioral and addition settings that include adult inpatient and outpatient mental health services with substance use disorders, and geriatric long-term care and hospice care.  He has a particular interest in psychopharmacology, nutritional psychiatry, and alternative treatment options involving particular vitamins, dietary supplements, and administering auricular acupuncture.

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