Can you refuse a drugs test?

Gail Evans, Alphabiolabs

By Gail Evans, Technical Trainer at AlphaBiolabs
Last reviewed: 29/09/2023

Six reasons why you can refuse a drug test at work; and why they won’t work.
Table of contents
  • Can you refuse a drugs test?
  • You haven’t been informed about the company drug testing policy
  • You can’t be forced to take a drugs test
  • You decline to take part
  • You have a medical condition that prevents you from giving a sample
  • You are on prescribed medication
  • You claim your sample has been tampered with
  • What happens if you fail?

Can you refuse a drugs test?

You are more likely to be asked to undertake a random drugs test by your employer if your job involves safety-critical work such as driving, operating machinery or looking after vulnerable people. As the name implies, this method involves selecting a number of employees at random at regular intervals and testing them, usually using urine or oral fluid drug tests.

There are several reasons why you can refuse a drugs test at work. However, any refusal is going to make your employer suspicious of your reasons for saying no.

1. You haven’t been informed about the company drug testing policy

If you have not been provided with information about your company’s drug testing policy you can refuse to be tested and your employer is not allowed to take any action against you.

Employers can only drug test their staff if there is a drug testing policy in place that you are aware of and that you have agreed to. This drug testing policy forms the foundation of a company’s drug and alcohol testing programme and outlines the approach to substance misuse. This is usually an official document, which provides formal information on what constitutes non-compliance. A well-written policy should also detail how substance abuse issues will be handled.

This drug testing policy could form part of your Staff Handbook or be specified in your contract. Check for this policy to see if your employer can perform a drugs test. Sometimes drug testing policies are introduced after you have been working somewhere for a while; in this case, you will have to accept this separately or agree to a change to your contract.

2. You can’t be forced to take a drugs test

An obvious reason to refuse is when you know that you have been abusing drugs, either illegal, prescription or over-the-counter, and do not want a positive result. In this case, you ideally want to delay any tests for as long as possible. The time taken for drugs to leave your system depends on what substance you have taken, and how much. Cannabis, for example, could stay in your system for up to 28 days. If you are a chronic long-term user, then the drugs may be more evident in your sample than for occasional users. However, if you refuse a drugs test when your employer has good grounds for testing you under a proper occupational health and safety policy, you may face disciplinary action. This could include being sacked.1

A comprehensive drug testing policy should encourage any employee with a substance dependency problem or other addiction to inform their Line Manager in confidence. Disciplinary action may be suspended whilst appropriate treatment and/or rehabilitation is sought.

3. You decline to take part

There are several reasons that you can use as a reason to decline taking part in a drugs test. You may find the tests required an invasion of privacy. You may have been unaware that regular testing was routine and are disconcerted because you were unprepared. You may not feel comfortable having to pee or provide an oral fluid sample on request. In all of these cases, a well-managed drugs and alcohol awareness policy should have explained the testing procedure and what to expect. This would help alleviate some of your concerns. The most common forms of workplace drugs testing involve taking a sample of saliva or urine in a professional and discreet manner. There should be no need for you to feel uncomfortable or pressured into doing something you don’t want to.

4. You have a medical condition that prevents you from giving a sample

If oral fluid testing is on the cards, then fear of saliva is a real condition. It usually affects people with obsessive-compulsive disorder (OCD). Individuals with this condition may fear not just their own saliva but the saliva from other people. They may also have phobias of other bodily fluids and waste products, including blood, urine and other excretions. For many with saliva phobia, this obsessive behaviour is uncontrollable without mediation and psychological counselling.

Fear of gagging, a sensitive gag response and emetophobia (a phobia that causes overwhelming, intense anxiety pertaining to vomiting) can also cause issues for individuals asked to perform an oral fluid test. Some people cannot cope with anything being in their mouth and there are physiological causes which can predispose or cause a person to gag. These include not being able to breathe through your nose properly, catarrh, sinusitis, nasal polyps, mucus in the upper respiratory tract, a dry mouth, and medications that cause nausea as a side effect. Certain medical conditions (gastrointestinal diseases) can also contribute to gagging.

As the oral fluid test involves placing a sample collection device in the person’s mouth for several minutes, this could be a real concern. If saliva phobia or fear of gagging are real concerns then an alternative testing method may be advised, or counselling initiated.

Shy bladder syndrome (known as paruresis) is when you have trouble urinating when other people are around. As such, the use of a urine drugs test could be avoided, or at the very least, postponed. This common social phobia is psychological and not a physical condition because nothing is wrong with the urinary tract. However, the urinary sphincter must be relaxed in order for urine to flow from the bladder down the urethra. Treatment involves graduated exposure therapy, perhaps three or four times per week. It is advisable to drink plenty of water before any practice session to make sure that your bladder is full. Individuals with OCD may also object to providing a urine test. Oral fluid testing may be advised as an alternative to a urine test.

5. You are on prescribed medication

One of the major reasons for refusing to take a drugs test is because an individual does not want it made aware that he or she is on prescribed medication. This could be antidepressants, for example, and the employee is concerned that there may be stigma associated with mental health issues. Alternatively, you may be worried that any medication you are taking will interfere with the drug testing result. It could even be that the drugs you are taking cause drowsiness and could impair your ability to do your job? Your company’s drug testing policy should advise that any prescribed medication is disclosed to your Line Manager. A good company has a duty of care to support its employees by assigning other duties, if necessary. Bear in mind that if you refuse a drugs test, you may face disciplinary action. This could include being sacked.1

6. You claim your sample has been tampered with

Drug test samples are usually collected by trained sample collectors who should follow the correct company procedure. Claiming that the sample taken was interfered with in with some way, or wasn’t even your sample, would be very difficult to prove as strict chain of custody conditions should have been followed. This involves the trained collector checking your ID, performing an adulteration check, and sealing the pot or collection device with tamper-tape. Should your concerns need to be investigated, the likelihood is that the test will need to be repeated, or another test method proposed.

What happens if you fail?

If the worst-case scenario happens and you fail a company drugs test you could face disciplinary action or be dismissed. The outcome will depend on your company’s policy and the nature of your work. If the company has a zero tolerance policy to drugs, just the positive test could be seen as gross misconduct and you could be dismissed immediately or suspended while there is an investigation. This is most likely to be the case if your job is safety-critical, such as driving or operating machinery. In such a case, specialist advice from an employment solicitor may be in order. If you are dismissed, your first port of call is to challenge this through your employer’s internal procedures. If your employer doesn’t change the decision you may want to appeal to an employment tribunal. If you are a member of a trade union, you should also check if you are able to get free representation through them.

For information on any of AlphaBiolabs’ workplace testing services, call us on 0333 600 1300; email:

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Gail Evans, AlphaBiolabs

Gail Evans

Technical Trainer at AlphaBiolabs

A professionally-trained forensic scientist, Gail joined AlphaBiolabs in 2012 and holds the role of Technical Trainer.

Her day-to-day responsibilities include delivering in-depth training sessions both internally and externally, covering DNA, drug, and alcohol testing.

Before joining the company, Gail was a practicing forensic scientist with 25 years’ experience working for the Forensic Science Service, attending scenes of crime, and analysing physical and biological material with potential evidential value.

Gail also holds qualifications in chemistry and is a Lead Auditor for the ISO 9001 standard, the international standard for quality management.

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