20 February 2026
A practical guide to managing prescribed cannabis in the workplace - balancing employee rights with health and safety.
The legal landscape has changed
Since November 2018, specialist doctors in the UK can legally prescribe cannabis-based medicinal products (CBMPs). This means employers are increasingly likely to encounter employees who use prescribed cannabis - and how they respond matters enormously, both legally and ethically.
Getting it wrong can expose a business to discrimination claims, health and safety liability, and insurance complications. Getting it right protects everyone.
Your key legal obligations
Employers must navigate several overlapping pieces of legislation:
Health & Safety at Work Act 1974: This requires employers to provide a safe working environment and ensure employees aren't impaired during safety-critical tasks. At the same time, employees have their own duty to take reasonable care of themselves and colleagues.
The Equality Act 2010: The Equality Act 2010 is critical. If an employee's underlying condition qualifies as a disability, blanket policies that penalise prescribed cannabis use could amount to direct discrimination or a failure to make reasonable adjustments. Treat each case individually - not as a category.
Road Traffic Act 1988: This allows employees with a valid prescription a statutory medical defence for driving, provided the drug was taken as prescribed and driving wasn't impaired. However (and this is important) that defence does not automatically protect their insurance cover.
The Right Way to Handle Disclosure
When an employee discloses they have been prescribed cannabis, follow a structured process:
1. Create a safe channel for disclosure: Designate a trained, discreet contact in HR or occupational health.
2. Obtain written consent: Obtain the written consent to process medical information, and explain how it will be used.
3. Request documentation: Ask for a valid prescription, dosage details, timing of doses, known side effects, and duration.
4. Refer to occupational health: Refer to OH for an independent assessment of functional impact and fitness for the specific role.
And remember: Never pressure employees to disclose, but make clear that voluntary disclosure protects both parties.
Assessing the Real Risk
Not all roles carry the same risk, and no two people respond to cannabis-based medication the same way. A meaningful risk assessment must consider:
Nature of the work: Is it safety-critical? Does it involve driving, machinery, working at height, or lone working?
Medication effects: Side effects can include drowsiness, dizziness, impaired cognition, and slower reaction times — but timing, duration, and individual tolerance all vary.
Working patterns: Can shift times or break schedules be adjusted to avoid peak medication effects?
Base decisions on evidence of actual or likely impairment - not on the fact that cannabis is involved.
Control Measures and Reasonable Adjustments
Where risk exists, consider a hierarchy of practical responses:
Temporarily remove the employee from safety-critical duties during peak medication windows.
Redeploy to lower-risk tasks or roles.
Adjust working hours to align with medication timing.
Increase supervision or introduce buddy systems for high-risk work.
Allow flexibility - amended start times, rest areas, time off for medical appointments.
Review your drug & alcohol testing policy – Ensure that it is now legal and considers prescription medication.
Reasonable adjustments must be practical, cost-proportionate, and must not create unacceptable risks for others. They don't have to be permanent - many situations can be managed during an adjustment or review period.
Don't overlook Insurance
This is where many employers are caught off guard. Prescribed cannabis can have significant implications for:
Employer's liability: Depending on the insurer and policy wording, failure to disclose a known risk could void coverage.
Motor fleet insurance: commercial vehicle insurers may require notification, impose exclusions, or increase premiums for drivers prescribed CBMPs.
Professional indemnity: consider whether errors linked to impairment would be covered.
Action required: Review all policies for drug-related exclusions, contact insurers in writing, and document everything.
The Golden Rules
DO'S
Assess every case individually on the evidence.
Involve occupational health professionals.
Keep medical information strictly confidential (it's special category data under UK GDPR).
Train managers to have supportive, objective conversations.
Document every step - assessments, adjustments, reviews, and insurance communications.
DON'TS
Don't apply blanket bans on prescribed medication.
Don't treat prescribed cannabis the same as recreational use.
Don't make assumptions about impairment without evidence.
Review your policy annually, after any significant incident, or whenever legislation or insurance terms change.
Further reading:
https://www.cicouncil.org.uk/resources/the-use-of-prescription-cannabis-at-work/
Medical cannabis and road safety
Chris Moore | Tech IOSH | AIFSM | L3CertFRA
Risk Management Development Director
chris.moore@verlingue.com