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Drinking Night Before Pre Employment Drug Test

Will drinking night before a pre employment drug test make you fail? Maybe.

In general, routine pre-employment drug tests are looking for illegal drugs rather than alcohol. But while alcohol screens are less common during the hiring process, they’re not unheard of, and any pre-employment drug test for a job that follows Department of Transportation regulations will include a test for alcohol.

In this article, we’ll go through the most common types of pre-employment drug tests and detail the substances they look for. We’ll also go over some alcohol metabolism basics to help you understand how long alcohol stays in your system at detectable levels.

Drinking Night Before Pre Employment Drug Test

Drinking Night Before Pre Employment Drug Test

Do Drug Tests Pick Up Alcohol Use?

Some do, and some don’t. The most commonly used pre-employment drug tests do not include an alcohol screen, although an employer can ask for a separate test for alcohol if they feel that’s necessary.

When you take a pre-employment drug test, you’ll usually take a 5-panel or a 10-panel drug screen.

Neither standard test looks for alcohol.

There’s a widespread misconception about drug tests, and many people worry that any substance they use is going to be picked up.

The truth is, that drug tests only detect the specific substances the test has been designed to find.

The next point to consider is the sample used for the test. You may be asked to give a urine sample, oral fluid sample, or blood sample. Sometimes you’ll need to provide some of your hair for a hair follicle test. And then there’s the breathalyzer test which analyzes your breath to detect your alcohol level.

Each type of sample has a different detection window for alcohol.

Let’s get into some details.

Does A 5-Panel Pre-Employment Drug Screen Include Alcohol Testing?

A 5-panel pre-employment drug test screens for:

  • Opiates
  • Cocaine
  • Marijuana
  • Amphetamines and methamphetamine
  • Phencyclidine (PCP)

The standard screen does not include a test for alcohol, but an employer may ask for a separate alcohol test, in which case you would be taking a ‘5-panel plus alcohol test’.

Read This Also: Drug Test For DOT Physical – What Does It Screen For?

Does A 10-Panel Pre-Employment Drug Test Look For Alcohol?

Again, the answer is not usually. Besides the drugs tested for on a 5-panel drug screen, a 10-panel drug test also looks for:

  • Benzodiazepines
  • Barbiturates
  • Methadone
  • Methaqualone
  • Propoxyphene

Employers sometimes request an additional screen for oxycodone and ecstasy, and they can also ask for a ‘10-panel plus alcohol test’.

If your test does include alcohol, the amount you drink and the length of time between your alcohol consumption and the test will determine if you pass or fail.

Alcohol Metabolism Basics

Alcohol Metabolism Basics

When you drink alcohol, your body processes and eliminates that alcohol at a certain rate per hour. To find out how much alcohol is present in your system, an alcohol test measures your blood alcohol concentration (BAC).

It’s not necessary to do a blood test to determine BAC, and the most common test used for alcohol is the breathalyzer test.

A breathalyzer test can provide an accurate measure of your BAC because of the known ratio of breath alcohol to blood alcohol.

Alcohol leaves the body at a rate of 0.015% per hour which equates to roughly 0.25 – 0.30 an ounce of ethanol per hour. Ethanol is pure alcohol, and alcoholic drinks contain varying amounts of ethanol.

A standard drink contains 0.6 fluid ounces or 14 grams of ethanol. The following common measures are considered standard drinks and each drink will contain 0.6 ounces of ethanol:

  • 12 ounces of beer (5% alcohol content)
  • 8 ounces of malt liquor or strong beer (7% alcohol content)
  • 5 ounces of wine (12% alcohol content)
  • 5 ounces or 1 shot of distilled spirits (40% alcohol content)

One standard drink containing 0.6 ounces of ethanol, metabolized at 0.25 – 0.30 of an ounce per hour, will be eliminated in roughly 2 hours, taking your BAC down to zero.

Factors like biological sex, weight, age, medications, sleep, the amount of alcohol consumed, and food can all influence your rate of alcohol metabolism, and there are some tools you can use to estimate how soon your blood alcohol concentration will return to zero.

For example, the calculator provided by American Addiction Centers at estimates your current blood alcohol concentration and the number of hours remaining until you’ll reach a BAC of zero.

To use the calculator, just enter the number of drinks you’ve had (or plan to have), your body weight, biological sex, and the time since your first drink, to get your estimate.

Basically, if you have a drug test scheduled in the morning, you’ll be able to have a few drinks the night before and still pass your drug test if an alcohol screen is administered.

How many drinks you can have will depend on what you drink, and at what time you start and finish drinking.

Let’s say it’s midnight and you’re taking a drug test tomorrow at 10 a.m. You’re a 160-pound male, you’ve had 4 regular beers, and you opened the first bottle 4 hours ago at 8 p.m. Your BAC, according to the calculator, is 0.07 and you’ll have to wait another 5 hours before you’re at BAC zero.

You’ll be sober at 5 a.m. in plenty of time for your drug test at 10 a.m.

What if you took a shot with each beer? Well now, you’re in trouble because you need to wait another 13 hours before you get a BAC of zero, which puts the time at 1 p.m., 3 hours after you need to take the test.

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What Blood Alcohol Concentration Will Fail An Alcohol Test?

Alcohol tests used for employment purposes don’t require a BAC of zero because there are some medical conditions, normal bodily processes, and external exposures that can register a small alcohol concentration on a test.

Conditions like ketoacidosis in diabetics, for example, fermentation of certain foods in the gut, and the use of mouthwash can all result in a BAC above zero.

Alcohol tests detect blood alcohol concentration levels above 0.02%, and the Department of Transportation in their drug and alcohol testing rules for transportation workers determines an alcohol level of 0.02% or higher as a failed test.

Now, you may not be taking a test for a DOT-regulated position, but many employers base their drug testing on those federal standards, and if that’s the case for your test, any level at or over 0.02% BAC will result in a failed test.

Alcohol test providers using a test that meets the standards for a federal evidential breath test (EBT) also use 0.02% as the cutoff point.

What results in a BAC of 0.02%?

Using the BAC calculator at, we can see that if you drink 1 regular beer, you’ll still have a BAC of 0.02% 1 hour later.

Now let’s plug in those 4 beers and 4 shots and see what happens.

Sixteen hours after the first drink, you would still have a 0.02% BAC and you would fail any pre-employment drug test during those hours that included an alcohol screen.

One or two standard drinks the night before a drug and alcohol test won’t be a problem, but a moderate to heavy drinking session will be, especially if your test is first thing in the morning.

And be warned, drinking lots of water before your test won’t make any difference to the result.

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How Long Can Alcohol Be Detected On A Drug Test?

How Long Can Alcohol Be Detected On A Drug Test?

Now you know how to work out how long alcohol stays in your system, you can plan for your pre-employment drug test. But what if the job you’ve applied for has a zero-tolerance alcohol policy that prohibits any alcohol use at all? How long can alcohol use be detected on a test?

If the alcohol testing method uses a saliva sample, alcohol can be detected for roughly 12 – 24 hours after the last use.

For urine samples, the alcohol detection window can be as long as 5 days on more advanced tests if heavy drinking has occurred. A normal urine test will detect alcohol for up to 24 hours.

Some pre-employment drug screens use blood tests and the detection window for alcohol in the blood is about 6 hours.

If you’re asked to take a hair follicle drug test, any alcohol use over the past 90 days can be picked up.

The most common pre-employment alcohol testing method is the breathalyzer test. A breathalyzer test measures the amount of ethanol in your breath and uses that measurement to establish the corresponding blood alcohol concentration. The detection window on a breathalyzer is roughly 24 hours.

These detection windows also apply if you’re asked to take a random, reasonable cause, or post-accident drug and alcohol test.

How To Find Out What Type Of Drug Test You’ll Be Taking

If you’ve already got a pre-employment drug test scheduled, you should have received a copy of the drug and alcohol policy in use by your new employer.

The drug and alcohol policy (or substance abuse policy) should contain details about the type of test you’ll have to take, and the substances you’ll be tested for.

So that’s your first option. Check your job offer for a link to the employee handbook or other policies, and read through the drug testing information.

If you didn’t receive any information, call the company and ask if the drug test includes alcohol. Alcohol is not an illegal substance, so it’s safe to ask.


Unless you’re taking a drug test for an employer that prohibits alcohol use at all times, having one or two drinks the night before your test shouldn’t cause you any problems.

Most employers don’t test for alcohol on a pre-employment drug test, but if you know that you’ll be tested for alcohol, you just need to be sensible about how many drinks you have.

To be on the safe side, use the BAC calculator to find out how long alcohol will stay in your body.

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