Procedure When an Employee Fails a Drug Test – UK Guidance
In the UK, the process following a failed drug test is governed by UK employment law, workplace policies, and industry-specific safety requirements. Employers have a duty to maintain a safe working environment, while also respecting employee rights under the Equality Act 2010 and data protection laws.
1. Initial testing and confirmation
If an employee returns a positive rapid onsite drug screening test result, further analysis should always be performed using a confirmatory lab drug test (typically using a UKAS accredited laboratory drug test, either liquid chromatography-mass spectrometry/mass spectrometry (LC-MS/MS) or GC-MS gas chromatography-mass spectrometry) The lab drug test is carried out to ensure accuracy. This type of confirmatory laboratory drug test is considered the gold standard and highest level of accuracy in workplace drug testing.
When this occurs, there will normally be a delay of several days before the lab result is available. If the employee is in a safety critical role, best practice is to suspend them from duties , pending the confirmatory drug test results, on full pay at the employers expense, and no other disciplinary action should be taken until the lab drug test result is available.
Before any action is taken, the advice of a Medical Review Officer (MRO) may be sought by the employer to discuss the laboratory results, and their significance in relation to over the counter and prescribed medications, and illegal street drugs, and whether there is a legitimate medical explanation, such as a prescription medication. This service is provided free of charge by our Medical Director on laboratory tests purchased from UK Drug Testing. Only after confirmation should an employer proceed with next steps.
2. Handling prescription medications
If the positive drug test result is linked to a prescribed medication, and the employee can provide evidence of a valid prescription, the result may be classed as negative for employment purposes. Employees in safety-critical roles have a responsibility to disclose, in confidence, any medication that may affect their ability to work safely. Employers must treat such information confidentially and in line with data protection regulations.
Even where a drug is legally prescribed, employers may still require a fitness-for-work assessment if there is a potential impact on safety. Reasonable adjustments should be considered if the medication relates to a disability under the Equality Act 2010. Misuse of prescribed drugs or failure to disclose relevant medication may lead to disciplinary action.
A fitness-for-work assessment is an evaluation to determine whether an employee is physically and mentally capable of performing their job duties safely and effectively. This type of assessment is typically conducted by an occupational health professional (such as a doctor or nurse) and is often required in situations where an employee has health concerns, has taken medication, or has experienced an injury or illness that may impact their work performance.
In the context of a failed drug test, a fitness-for-work assessment may be used to assess whether the employee is fit to return to work or whether the prescribed medication or any drug-related impairment would affect their ability to safely carry out their duties. The assessment looks at:
- The potential impact of medications or substances on performance and safety
- Any underlying medical conditions that could affect job performance
- Whether reasonable adjustments or temporary changes to duties are necessary
The goal of the assessment is to ensure the employee's safety, the safety of their colleagues, and the smooth operation of the workplace.
3. Investigation and disciplinary process
Once a positive onsite drug test result is confirmed, the employee should be invited to a formal meeting to explain the circumstances. They are entitled to be accompanied by a colleague or trade union representative. The employer must follow their own disciplinary procedures, in line with the ACAS Code of Practice, and ensure a fair and impartial investigation.
The response will depend on the role and the company's drug and alcohol policy. In non-safety-critical roles, a first offence may lead to a warning, occupational health referral, or support through an Employee Assistance Programme. In safety-critical roles, a positive test may constitute gross misconduct and could result in suspension or summary dismissal.
4. Legal considerations
Employers must act reasonably and lawfully when responding to failed drug tests. Disciplinary action, including dismissal, must be procedurally fair and proportionate to the circumstances. Employees with over two years’ continuous service have the right to claim unfair dismissal if procedures are not followed. Employers must also consider whether drug misuse is linked to a health condition, addiction, or disability that may require support rather than sanction.
5. Return to work and ongoing monitoring
If dismissal does not occur, the employee may be subject to a return-to-work agreement which could include follow-up drug testing, monitoring, and ongoing occupational health support. Any measures taken should be documented and agreed upon with the employee.
6. Drug and alcohol policy recommendations
Employers should ensure that drug and alcohol policies are clearly communicated and regularly updated. These policies should include provisions for:
- Voluntary disclosure of medication that may impair performance
- Confidential handling of medical information
- Clear procedures for drug testing, investigations, and disciplinary action
- Access to support and drug or alcohol rehabilitation where appropriate