What Is Drug and Alcohol Testing?

27th September 2017

Updated October 2023

Workplace drug and alcohol screening is on the rise in the UK. Used appropriately it can be a vital step in helping keep your employees and your workplace safe.

While screening can be seen as controversial, when it comes to potentially hazardous work environments (in the construction industry, for example) or safety-critical situations, workplace drug and alcohol testing is often a smart move.

For instance, we recently had a group of plumbers and electricians from a local firm who had been offered positions at a nuclear plant. Their employer needed formal evidence that they were clear of drink and drugs before they could commence work at the site – a quick, non-invasive test was able to supply that.

Of course, as well as controversy there is a lot of confusion around drug and alcohol testing too. And as an employer, it’s important you understand exactly what you’re asking of your employees so you can make informed decisions about when it’s necessary, and how to carry it out.

In this post, we’re going to explore the ins and outs of workplace drug and alcohol screening. We’ll answer some commonly asked questions about the process as well as discuss the different methods available to help you pinpoint which would be the best for your company. We’ll also explore how we carry out our own drug and alcohol testing procedure.

Image of a sample pot and a drug test result form ready to be filled in.

What do workplace drug tests test for in the UK?

Drug testing can pick up on a range of drugs, though it is most common to test for cannabis and cocaine. The majority of employers also choose to run wider workplace drug tests that detect the use of amphetamines, benzodiazepines, opiates as well and even MDMA and ketamine.

Here at David Barber Occupational Health our drug tests detect the following substances:

  • Barbiturates
  • Methadone
  • Benzodiazepines
  • Cannabinoids/THC
  • Cocaine metabolites
  • Opiates
  • Amphetamine
  • Phencyclidine
  • Methamphetamines
  • Ketamine

What are 5 common ways to test for drugs and alcohol?

The most common ways to test for drugs and alcohol in the workplace are:

  • blood tests
  • urine tests
  • breath alcohol testing
  • hair drug testing
  • saliva testing

Though the most common type is urine tests, there are a range of pros and cons to all methods.

Blood tests

Blood testing is the most flexible type of drug and alcohol test as it can be used to detect a wide variety of drugs alongside levels of alcohol.

However, it is rarely the most efficient method of drug and alcohol screening. There is actually quite a short window where you can detect drugs in blood – it takes a couple of hours for drugs to appear and they will only be traceable for around ten hours after that.

They are also more expensive to carry out and process.

Blood tests are far from ideal from an employee’s perspective too. Having one can be painful, and often feels invasive – this creates a lot of resistance to the process, making it a lot more difficult and upsetting than it needs to be.

Urine drug tests

With urine drug testing, employees give a urine sample which is then screened for traces of drugs and alcohol.

They can pick up on the drug itself, as well as any metabolites or biomarkers that are created when the body breaks down and processes the drug. They can detect recent or past drug use covering days, weeks and months after use. This type of test can be less reliable when it comes to current intoxication though.

Breath alcohol testing

One of the most well-known alcohol screening methods uses breath. To carry out a breath alcohol test, you exhale into a breathalyser which measures the concentration of alcohol on your breath (Breath Alcohol Content or BrAC).

It immediately shows whether a person is over the legal limit (in the UK that’s 35 micrograms for every 100 millilitres of breath). This method is common all across the world, including by police forces, as a frontline way to identify excessive or inappropriate alcohol consumption.

Testing saliva

A saliva test is taken by gently swabbing the inside of a person’s mouth with a cotton swab. This oral fluid is then analysed for traces of drugs.

The biggest benefit of saliva drug testing is that it can detect recent drug use – quicker than urine analysis in many cases. However, it also leaves a much shorter detection window.

It is less painful than a blood test, though it can be slightly uncomfortable. It is more invasive than hair or urine testing too, but it is a lot harder to tamper with than urine drug testing.

A sample of blood labelled for a drug test

Testing hair

Hair drug testing delivers highly accurate results but has a lot of drawbacks. One of these is collecting the hair for testing- though the collection method is non-invasive, a sizable sample is needed. It is also important not to test the follicle itself, so it is best to have the sample taken by a trained professional to ensure a reliable result.

Hair testing also has a very long detection window – it can detect the use of certain drugs weeks after they were used. However, in a workplace setting this is rarely useful as it is not always possible to prove historic drug use is relevant.

What type of drug test do most employers use?

Urine tests are the most common choice of drug and alcohol testing method when it comes to workplace testing. This is because it has benefits for both employees and employers.

From an employee’s point-of-view it is one of the least invasive methods, with no needles or swabs needed. This makes it the most comfortable option, though some people may still find it embarrassing or difficult to complete.

From an employer’s point-of-view it is a reliable and cost-effective option. A urine drug test can be used to detect a wide variety of drugs if they were taken in the last 4-72 hours (though as with all testing methods, the detection window can vary depending on the drug).

Another benefit of urine drug testing is that you can get rapid same-day results, as well as send samples off for more in-depth analysis. Samples are also easier to store than some other methods.

The biggest drawback with this drug testing method is how easy it can be to tamper with. This said, there are plenty of safeguards you can put in place to protect against tampering.

Here at DBOCC, we use urine analysis for our workplace drug testing as we find it the most efficient and effective method.

What is looked at in urine drug testing?

A major benefit of using urine workplace drug testing is the wide range of substances it can detect. This includes alcohol, amphetamines, barbiturates, benzodiazepines, cocaine, fentanyl, cannabis, nicotine, opioids, and phencyclidine.

Here at David Barber, our urine tests can detect 8 substances including barbituates, cocaine and methamphetamines. 

Image of a lab technician holding an empty urine sample cup.

How do you perform workplace drug screening?

Obviously, different types of workplace drug and alcohol testing programmes will have different procedures. Here at DBOCC, we have a very strict process for carrying out our tests to make sure we get fair and reliable results. As the results of these tests can have long-reaching consequences, we make sure that both employers and employees are protected.

We start by preparing the bathroom. We’ll clear the space of bins, soaps, bleach etc or anything that could be used to pollute samples or affect test results. We’ll also search the area to make sure there is nothing hidden in the room, and make sure the room is secure so nothing can be bought into the testing area.

We’ll also add a coloured liquid to the toilet bowl. This means that if someone tries to tamper with the test and flush the toilet, we can spot it immediately.

With all these checks carried out, we can begin testing. We ask the person being tested to remove any outer clothing and hats, then empty their pockets. We also ask them to fill in a form with their name, address and DOB. Ideally, we ask to see a photo ID – if this isn’t possible, we’ll ask their Manager to formally identify them.

Next, we’ll ask some questions to check if they’ve taken any prescription or over-the-counter medication, had any alcoholic drinks or even eaten anything with poppy seeds on it. Any of these can skew the accuracy of the tests.

Before doing the test, we’ll also ask the person to sign to say they’ve agreed to take part in the testing process. If they refuse, the matter is reported to HR to follow. In many cases, this counts as an instant fail depending on the company policy.

If they agree, then we walk them to the bathroom to carry out the test.

The results of the test will show on a strip inside the pot which looks similar to a pregnancy test. If has a non-negative result, the urine is decanted into the laboratory tubes and sent for further testing.

The pots are sealed with an anti-tamper seal and placed in a padded envelope ready for posting to the lab. The test is then complete.  The two lab pots will be sent off and tested for drugs and alcohol.

What if you only need an alcohol test?

For alcohol screening, we use a breathalyser test. As mentioned above this is a straightforward test that gives an immediate result.

Helping to keep your workplace safe

As an employer, keeping your workplace and your employees safe must always be a priority. Drug and alcohol screening can be a vital part of that but only if they are handled correctly.

However, a screening programme best protects your workplace if used as part of a health and safety package. Here at DBOCC, we can support you with risk assessments, health surveillance and a range of other occupational health services that will keep your employees supported and your workplace safe.

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