Medical cannabis and disability discrimination: lessons from Truman v SPL Powerlines

The Employment Appeal Tribunal’s decision in Truman v SPL Powerlines UK Ltd and others [2026] EAT 54 highlights the legal risks of applying a blanket approach to positive drug test results without considering individual circumstances.

Background to the case

Mr Truman, a long-serving rail worker, had been prescribed medical cannabis to manage the chronic pain arising from genetic haemochromatosis. He applied for a safety-critical role with SPL Powerlines, which required him to pass a drug and alcohol test in line with Network Rail’s policy. Under that policy, a ‘fail’ could be recorded as a ‘pass’ where there was a legitimate medical explanation.

Although Mr Truman disclosed his prescription, the test result, showing cannabis in his system, was recorded as a ‘fail’. As a result, SPL Powerlines withdrew the job offer, and Network Rail imposed a five-year ban on him undertaking safety-critical work.

Mr Truman brought claims for disability discrimination. The Employment Tribunal found that, had the policy been applied correctly, the result should have been recorded as a ‘pass’ because there was a legitimate medical explanation for the substance detected. However, it dismissed the claims, comparing Mr Truman with a non-disabled person who had failed a drug test and concluding that any disadvantage arising from a failure to make reasonable adjustments was not significant.

On appeal, the Employment Appeal Tribunal held that the correct comparator was an individual who would have passed the test under the policy’s medical exemption, had it been properly applied. Given the Tribunal’s finding that Mr Truman’s result should have been treated as a pass, it could not properly conclude that the disadvantage he suffered was insignificant.

What does this mean for employers?

Employers remain entitled to enforce genuine safety requirements, particularly in high-risk environments. However, reliance on policy wording alone will not be sufficient. A positive drug test should not automatically result in rejection of a job application or disciplinary action where prescribed medication may be relevant.

What should employers do now?

• Review policies: Ensure drug and alcohol policies clearly address prescribed medication, including how legitimate prescriptions will be assessed.
• Train managers: Ensure those responsible for applying policies understand them and apply them consistently so that avoidable errors do not escalate into tribunal risk.
• Avoid automatic decisions: Do not adopt a ‘zero tolerance’ approach where a positive result may be linked to prescribed medication.
• Assess medical evidence and reasonable adjustments: Consider obtaining medical evidence, carrying out risk assessments, and identifying reasonable adjustments where appropriate before reaching a final decision.
• Exercise care in recruitment: Withdrawing an offer can still give rise to discrimination claims, so decisions at this stage should be handled with particular care.

Contact our employment law solicitors today

If you would like advice on reviewing your policies or managing situations involving prescribed medication, our team at Ashtons Legal is happy to help. Please contact a member of our Employment Law team. You can use our online enquiry form or call 0330 191 5713.