Drug Testing 101

Drug Testing 101

Employers often justify drug testing on health and safety grounds, particularly in safety-critical jobs like driving or medicine. They may also cite concerns over employee absenteeism or job performance.

The practice has increased dramatically in the UK over recent years. Indeed, many businesses seem to have latched on to drug testing as a way to dismiss employees without paying them .

Informed consent

Your employer must obtain your informed consent before they perform a drug test. This means they have to explain the purpose of the test and wait for you to agree to be tested before taking a sample.

Your employer certainly cannot force you to take a drug test or covertly test you. If your employer tests you without informed consent, you should speak with a solicitor since this is unlawful. Moreover, even if you fail the drug test, your employer cannot rely on the illegally obtained sample to dismiss or discipline you.

Of course, if you unreasonably decline to take a drug test (e.g., you have a contractual obligation to take one), you should expect to face disciplinary action and, quite likely, dismissal over the refusal.


If your employer wants to carry out drug testing, the first thing you should do is take a look at your employee handbook or contact of employment. This should outline how and when they plan to conduct tests, and what happens if you fail one.

If your employee handbook or contract does not discuss drug testing then your employer may not be able to ask you to undertake such a test. You should raise any concerns you have regarding the legality of the test with your supervisor and/or follow your employer’s grievance procedure (this should be explained in your employee handbook).

There is no legal requirement that an employer provide advance notice of testing, however, which can be problematic if you have recently taken a drug like , which remains detectable in your urine for several weeks after use.


If your employer has reasonable grounds to test employees (e.g., because of the nature of your job) and says it will select people randomly, selection must be genuinely random. If you employer singles you out for a test without valid justification, you may be able to claim unfair discrimination.


The results of your drug test must remain confidential, even if you fail a test. Moreover, because of the sensitive nature of testing, it should be conducted by a person of the same sex.

Failed drug test

If you fail a drug test, your employer may be able to dismiss you summarily for gross misconduct, particularly if you work in a safety-critical profession, your drug use has noticeably impacted your job performance or it adversely affects your employer’s business or reputation.

(NB. Being summarily dismissed for gross misconduct is significant because it may excuse your employer from having to provide notice and pay you .)

First things first, however, check your employment contract to see what it says your employer can do.

Appealing a dismissal over a failed drug test

You can challenge a drug test dismissal through your employer’s internal grievance procedure. If your employer rejects your appeal, you could then take your case to an employment tribunal. In either event, you are strongly advised to seek the immediate help and advice of an experienced .

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