Understanding Workplace Alcohol Testing

In this article we will examine the different types of alcohol testing commonly used in the workplace. Some of these testing methodologies can be used also for other alcohol testing situations such as court ordered testing, probation testing, DUI testing, child custody testing and child welfare testing.

The types of alcohol testing we will cover are:

More information regarding alcohol testing is available on our National Drug Screening (NDS) web site:

EtG Alcohol Testing – https://www.nationaldrugscreening.com/etg-alcohol-test/

Alcohol Drug Test Panels – https://www.nationaldrugscreening.com/alcohol-drug-test-panels/

Breath Alcohol Testing

We have all heard of a Breath analyzer (Breathalyzer is a brand name and commonly used name) typically concerning law enforcement and drinking and driving. Also, this is commonly called evidential breath testing device (EBT). This a device for estimating blood alcohol content (BAC) using breath as the specimen.

For workplace alcohol testing this the most common method for an alcohol test. It is also the required alcohol test for employers regulated by the United States Department of Transportation (DOT). DOT requires the evidential breath testing device (EBT) being used for DOT alcohol testing be approved by the National Highway Traffic Safety Administration (NHTSA).

The workplace alcohol testing performed with a breathalyzer is administered by a Breath Alcohol Technician commonly called a BAT. The individual must be trained and qualified to utilize the particular brand of evidential breath testing device (EBT) (breathalyzer) they are utilizing.

Saliva Screening (Instant)

An instant screening device using saliva as the specimen to be tested is also used for workplace alcohol testing. As the name implies this is a screening device and negative results are acceptable. For results that are 0.02 positive, a second confirmation test using an evidential breath testing device should be performed 15 minutes later. The results of this second test would be the official result.

This process is allowed for DOT alcohol testing as long as the alcohol screening device (ASD) is also approved by the National Highway Traffic Safety Administration (NHTSA). There is a conforming product lists (CPL) for alcohol screening devices published by the National Highway Traffic Safety Administration.

The person performing the testing with the saliva screening device is commonly called a Screening Test Technician (STT). This person who instructs and assists employees in the alcohol testing process. Training and qualification are required for the STT to administer these tests.

Some examples of approved alcohol screening devices:

QED Saliva Alcohol Screening Test – https://alcopro.com/product/qed-saliva-alcohol-screening-test/

Alco-Screen 02 Saliva Alcohol Screening Device –

Oral Fluid Alcohol Testing

Oral fluid can be collected and sent to a lab for drug or alcohol testing. This is commonly called lab-based test and at the lab testing can be just for drugs or both drugs and alcohol. Many times, employers administer the specimen collection in house at their place of business.

Some major laboratories can perform alcohol testing with this method, not all Labs have this available. Some specific oral fluid collection devices are available for lab-based alcohol testing with oral fluid, not all of the oral fluid collection devices are configured for alcohol testing. With this testing method there is an excellent correlation between ethanol in breath and ethanol in blood. This testing is not approved for DOT testing programs.

This drug and/or alcohol testing goes through initial screen at the lab and if non-negative confirmation testing. It is common that oral fluid alcohol testing may be performed as a single test or as part of a drug panel. Some State laws (Minnesota for example) required all specimen to a laboratory for any workplace drug or alcohol testing, in that case the lab-based alcohol test is a great option.

The Quantisal™ collection device is widely used for oral fluid drug testing and has availability for lab based oral fluid alcohol testing. https://immunalysis.com/products/oral-fluid/quantisal/

Blood Alcohol Testing

Blood alcohol testing is a true measurement of alcohol concentration in the blood and shows impairment. The amount of alcohol in the blood reaches its highest level about an hour after drinking. The amount of alcohol in a person’s blood is called their blood alcohol content (BAC) or blood alcohol concentration. For DOT and most workplace testing a BAC of 0.04 is a violation. For a BAC of 0.02 to 0.04 the person has consumed alcohol and should be taken out of service till the next day.

In some States (Florida for example), for workplace alcohol testing blood is the required specimen. For DOT and in most States, blood is not used for alcohol testing.

The blood alcohol test is invasive and expensive. Alcohol blood testing is more often used during an investigation or court case. Company policy, Federal regulations and State laws should be reviewed for the potential of using or not using the blood alcohol test. This testing in workplace settings is uncommon except as required for State laws and State law drug free workplace programs like in Florida.

Urine Alcohol Testing (ethanol)

Urine alcohol testing is not recommended for workplace testing. The results of the urine alcohol test do not measure current impairment. In fact, urine alcohol tests are quite sensitive and can detect very low levels of alcohol and can do so up to several days after consumption. You might get a positive on an employee who had a glass of wine the previous evening at home with dinner. Additionally, the urine alcohol test for ethanol can also produce “false positives” for individuals with certain medical conditions (e.g., diabetes).

The urine alcohol test for ethanol for workplace testing can lead to significant liability if an employer uses these test results for adverse action against an employee. The urine alcohol test is also prohibited for DOT required drug & alcohol testing programs.

A urine alcohol test for ethanol can be combined with a urine test for drugs. This type of test is often used for probation testing, court ordered testing or zero tolerance programs where alcohol consumption is prohibited. A common example is a urine specimen five panel drug test plus ethanol.

EtG Alcohol Testing (urine and hair)

Alcohol tests may be conducted by collecting urine or hair samples using a technique to analyze the sample for the presence of Ethyl Glucuronide (ETG), an alcohol metabolite. Ethyl glucuronide has been shown to be a sensitive and specific marker for ethanol consumption is detectable in urine for up to 80 hours after alcohol has been ingested and up to 90 days with a hair sample. EtG testing is not recommended for workplace testing as it does not measure current impairment.

EtG alcohol testing has become very popular with court ordered testing and other zero tolerance alcohol abstinence programs such as with repeat DUI offenders or child custody cases where alcohol is a problem with one or both parents.

The presence of the EtG metabolite in urine or hair is a definitive indicator that alcohol was consumed, but again does not indicate current impairment. The main purpose of the EtG testing with urine or hair is to determine alcohol abstinence. The testing can also be conducted with fingernails or blood, but most often urine or hair is the specimen utilized.

Consuming food products with alcohol could cause a positive EtG test. In addition, many environmental or home products contain alcohol that could trigger a positive EtG results. These include: Aftershave, Hair dye, Hygiene products like antiperspirant, Mouthwashes Hand sanitizers, Breath sprays, Cleaning products, Cosmetics, Foods prepared with or flavored with alcohol. At National Drug Screening we recommend a minimum cut off level of 500ng/mL for the EtG test so as to decrease the possibility of a positive due to food or household products.

EtG testing does not measure the number of alcohol drinks one has consumed. The test is for any consumption at all of alcohol, not the specific amount or determining intoxication.

More on EtG Alcohol Testing – https://www.nationaldrugscreening.com/etg-alcohol-test/

PEth Blood Alcohol Testing

Peth blood alcohol testing is not recommended for workplace testing as it does not measure current impairment. This blood test is measuring for phosphatidylethanol, an alcohol-specific biomarker, in the blood. Phospholipid (Peth) is formed with the presence of ethanol and is then bonded to the membrane of red blood cells. The more alcohol consumed, the more Peth will be formed. This test generally requires daily consumption of alcohol to show a positive. The test is designed to detect heavy consumption of alcohol going back 2-4 weeks prior to the blood collection.

A single drink will not typically cause a positive on the Peth blood alcohol test. PEth testing will not detect food or household products that have alcohol in them. The detection is that the PEth is present in the specimen; there is no detection of impairment, time, dose, or frequency of use.

The blood testing for PEth is most often used in court ordered cases and child custody cases. It is common for those with a serious drinking problem who is not required or volunteering to not consume any more alcohol.


In general, in the workplace alcohol testing is utilized for post-accident and reasonable situations. It is not typically used for pre-employment. Some DOT agencies require random alcohol testing, some do not. To properly service their employer clients, drug testing service providers should have available methods for alcohol testing.

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