Failed Drug Test At Work - A Guide for Employers

A failed drug test can lead to disciplinary action, suspension or dismissal - the exact outcome will depend on the company's alcohol and drugs policy.


James Rowland

Commercial Director James leads Account Management, Sales and Marketing at Neathouse Partners.


07 June 2022


17 July 2024
4 min read
Failed Drug Test At Work - A Guide for Employers

A failed drug test at work can lead to disciplinary action, suspension or dismissal for employees but the exact outcome will depend on the protocols outlined in any alcohol and drugs policy that exists at their place of work.

If an employee tests positive for drugs or alcohol and therefore fails a drug test at work, they should be interviewed by the doctor overseeing the testing to determine if anything else could have impacted the result, such as prescribed medication. 

When dealing with a failed drug test, employers must uphold their legal obligations to maintain workplace safety, whilst treating employees fairly and without judgement. This combination of factors will ultimately decide the course of action that will be taken in each case.


The Importance Of Drug Policies At Work

Legal or illegal drugs can alter an individual's state of mind and awareness. This makes them a major safety risk to the user and others working with them in the workplace and is a particular concern in safety-critical roles where it’s illegal for machine or vehicle operatives to be under the influence of alcohol or drugs. Outside of immediate safety concerns, employees must be fit to work, meaning they need to be free of drugs or alcohol in their system.

It’s for these reasons that we recommend that all employers put in place a comprehensive but clear drugs and alcohol policy that proactively addresses the issue, outlines your tolerance to drugs, their use in the workplace and what happens when employees breach the policy communicated with them. Drug testing at work may form a part of this policy and act as a line of defence against the effect of employees taking drugs that will negatively impact their ability to work safely.


Drugs Testing Policies & Advice For Employers

Neathouse Partners provide solution-driven outsourced HR support for employers. If you need help with employee policies, staff handbooks, or managing difficult conversations including dismissal or discrimination discussions surrounding drug testing at your place of work, then our experienced HR professionals and employment lawyers can help you expertly navigate HR matters like these with the sensitivity and pro-activeness they deserve, regardless of how complex the issue may seem.

Failed drug tests at work can be stressful for all involved but employers need to know the procedures to follow, how to manage employees seeking help and their legal obligations under the Health and Safety at Work Act 1974, the Transport and Works Act 1992 and the Misuse of Drugs Act 1971 to ensure that they implement practices and policies that protect themselves and their employees regarding drug use in the workplace.

Read on to find out more about drug testing at work, your obligations as an employer, and the steps to follow when drug tests are failed.


What Is A Drug Test At Work?

The most common form of drug testing at work is a urine sample that tests for cannabis, cocaine, amphetamine, methamphetamine, benzodiazepine and opiates, and failing a drug test can lead to disciplinary action or dismissal for employees.

A drug or alcohol test looks for the presence of chemicals that remain in the body after the drug that has been taken has broken down. The tests cannot confirm if an employee is under the influence of drugs, only that there are traces of the chemicals in their system as a result of taking the drugs recently.


Employer Obligations & Recommendations

You have a legal obligation to protect and support employees in your organisation and should as a result be familiar with the following legislation when it comes to drug testing and associated policies at work:

  • Health and Safety at Work Act 1974 - section 2 & Management of Health and Safety at Work Regulations 1999 - Place an obligation on you to ensure and assess as far as reasonably practicable the health, safety and welfare of people at your workplace, meaning employees shouldn’t be under the influence of drugs in the workplace and you could be prosecuted if they are.
  • Misuse of Drugs Act 1971 - it is an offence for someone to knowingly permit the product, supply or use of controlled drugs on their premises
  • The Transport and Works Act 1992 - it is a criminal offence for certain workers to be unfit through drugs and/or drink while working on railways, tramways and other guided transport systems.

Most companies will have an alcohol or drugs policy and this should ensure that problems are dealt with effectively, and consistently and efficiently. If part of this policy relates to drug testing, then you should be aware that:

  • You cannot force employees to provide samples of urine, hair, saliva or blood for any purpose, including drug testing. However, if your employees have a contractual obligation to comply with drug testing and provide samples, then they subsequently refuse to do so, there may be grounds for dismissal in certain circumstances.
  • Your drug and alcohol policy should be clearly outlined in the staff handbook, including the consequences for workers who breach it.
  • When drug testing at work, you must tell workers what drugs they are being tested for. These should only be substances and exposure levels that will have a significant bearing on the ability to carry out work safely.
  • When conducting routine or ad-hoc drug tests employers should have a medical doctor available to provide assistance and professional advice on the day. Should a test return positive, the employee should be interviewed by the doctor to determine if anything else could have given a positive reading such as prescribed medication before any disciplinary action is taken.
  • When positive results are returned, a confirmation test should be given to confirm it’s not a false positive.
  • Anyone who conducts any kind of analysis for drugs should be accredited by the UK Accreditation Service and comply with the International Standard for Laboratories (ISO 17025)
  • Privacy and data protection considerations must be met when dealing with employees' health and personal records relating to drug testing.
  • Managers should be trained to spot signs of workers needing help and where they can direct staff for advice and support when needed.

What Happens If An Employee Fails A Drugs Test

Whilst failing a drug test can ultimately mean an employee will be dismissed or suspended, it’s important to take appropriate steps to fully investigate and manage the situation before any official action is taken.

A positive drug test can occur due to legal or illegal drug use, or as a consequence of taking prescribed medication and any positive result should be confirmed with a confirmation test which is independently checked and verified.

Additionally, an assessment with a qualified medical professional should take place with the affected individual to discuss any reasons that may have led to the positive test outcome.



Employers have a legal obligation to ensure the health, safety and welfare of employees at work. If carrying out drug testing as part of implementing a drug and alcohol policy, you need to be aware that this can be a stressful experience for employees that cause stress or an inability to cope. When requesting tests and reading results, you should always treat employees with compassion and kindness, even if a positive result is returned.

As drug tests are not infallible, a failed drug test at work can be contested, redone, and independently checked and verified. The eventual outcome when an employee fails a drug test will depend on your company’s policy on drugs, the situation that led up to the testing and if a confirmatory test was also positive.

See HSE guidance for more information on drug misuse in the workplace or contact Neathouse Partners to discuss the ways the team can support you in managing employee behaviours and policies regarding drug and alcohol use at work.

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