Alcohol and drugs at work: what are the rules?

A positive drugs test can cost you a job, shifts or a safety-critical career, even when you took a medicine legally. It does not prove you were impaired or make dismissal fair. Today, save the test result and policy, write down what happened and when, and ask for the evidence and next steps in writing. If your job is at risk, contact your union or Acas now. The claim deadline may be ticking while an appeal is underway.

What the law starts from

Cannabis remains a Class B controlled drug. Unlawful possession can carry up to five years in prison, an unlimited fine or both. Supply or production can carry up to 14 years. Being off duty does not make recreational possession lawful.

Cannabis-based medicinal products moved to Schedule 2 of the Misuse of Drugs Regulations 2001 on 1 November 2018. A doctor on the GMC Specialist Register must initiate treatment. A lawful prescription permits possession and use as directed, but does not override workplace safety or guarantee fitness for every duty. The prescribing rules give no separate employment right.

Alcohol is lawful, but your employer can prohibit drinking during a shift and require you to arrive fit for work. Check whether the policy covers on-call time, company vehicles and work-related events. Criminal rules also apply to driving and certain transport duties.

CBD products need care too. Some may contain THC that a test detects. A product being sold openly does not prove that all its contents are lawful or that it will produce a negative result. If you work in a tested role, ask occupational health about the product before using it. Do not treat “CBD” on the label as a defence to a policy breach.

Safety duties and criminal limits

In Great Britain, the Health and Safety at Work etc Act 1974 requires employers to protect employees’ health, safety and welfare so far as reasonably practicable. They must also protect others affected by the work. Employees must take reasonable care of themselves and others. Risk assessments should address impairment where it could make driving, machinery, work at height or other duties unsafe.

There is no general statutory requirement for every employer to have a drugs-and-alcohol policy or to test staff. The HSE describes screening as optional and says it should sit within a wider health-and-safety policy. If your employer tests, the procedure and interpretation must be reliable. An instant screening result may need laboratory confirmation before it can support a disciplinary decision.

For driving, the criminal thresholds are separate from your workplace policy:

The alcohol limits do not tell you how much you can safely drink; a lower reading does not prove fitness. For example, 60mg per 100ml blood exceeds Scotland’s limit but not England and Wales’s. A cross-border fleet can use one stricter policy instead of different allowances.

The drug-driving rules distinguish exceeding a specified blood limit from driving while unfit through drugs. A medical defence may apply to the specified-limits charge where you took a prescribed drug in accordance with medical directions. It does not excuse driving while impaired. It also does not override your employer’s fitness-for-duty rules.

What should a workplace policy say?

A written policy helps you know what is prohibited and what happens if there is a concern. Without one, an employer can still act on a serious safety breach. But an undisclosed testing rule or unexpected sanction can be harder to defend.

If you are drafting or checking a policy, look for:

• Rules on drinking, possession, supply and impairment, including on-call duties, vehicles and work events.
• When testing happens, who is selected and why. Random testing needs justification for the particular roles.
• Sample methods, laboratory, cut-offs, confirmation and challenges, including duplicate samples for independent analysis where appropriate.
• Confidential disclosure of medication or dependency, occupational-health assessment and treatment support.
• Consequences of breaches and refusals, including what the employer regards as gross misconduct.
• Access to test data, retention periods and deletion.

Consult staff and representatives before introducing testing. If you are asked to test, request the policy and reason. “Zero tolerance” does not remove the need for reliable evidence or consideration of disability.

Testing: can you be made to take one?

You cannot be forced to provide a breath, urine or saliva sample in an ordinary workplace. That is different from being free of consequences. The HSE says refusal can lead to disciplinary action where your employer has good grounds for testing.

A policy clause does not justify every test. Observable impairment after a forklift collision may support testing; an argument with a manager alone does not. Explain any objection about the method, medication or missing policy.

Results are special-category health data under UK GDPR. The ICO advises a data-protection impact assessment covering necessity, alternatives and safeguards. Testing should usually address safety, not uncover off-duty illegal use. Agreement to provide a sample is separate from data-processing permission. Employers need a lawful basis and a special-category condition; consent is generally unreliable because of the employment power imbalance.

Your employer should explain the test, access to results and consequences, keep records confidential and delete unnecessary data. A manager may need a fitness assessment, not your medical history. See workplace monitoring.

After a shift, save the policy, result, rota and messages. Note the test date, who was present, medication disclosed and what you were told. Ask in writing for the policy, reason, confirmed result and hearing date. Do not sign an account you dispute. Ask your union rep to attend the hearing.

1. Check the reason. Ask which policy provision or safety concern justifies this test.
2. Explain medication. Give relevant prescription information to the testing professional before they interpret the result.
3. Challenge unreliable evidence. Ask about laboratory confirmation and independent analysis, rather than accepting a screening result as conclusive.
4. Record any refusal. Explain your reason in writing. Your employer should investigate it before deciding on discipline.

Can you work with prescribed medical cannabis?

A prescription is evidence that you are taking a medicine lawfully. It is not evidence that you are impaired, and it is not a guarantee of fitness for every job. Your employer should assess the medicine’s effects alongside your condition and duties.

In Great Britain, adjustment duties attach to disability, not a prescription. The Equality Act requires a substantial, long-term adverse effect on normal day-to-day activities. Long-term generally means at least 12 months, including likely future effects, or the rest of your life. Adjustments must be reasonable. Safety matters, but a blanket cannabis ban does not replace assessment. See reasonable adjustments.

In Truman v SPL Powerlines UK Ltd and others [2026] EAT 54, prescribed cannabis treated haemochromatosis pain. A failed pre-employment test caused a withdrawn offer and a five-year safety-critical rail ban. The tribunal found that correctly applying the policy should have produced a pass because of his legitimate medical use.

The Employment Appeal Tribunal remitted part of his adjustment claim against Network Rail, but dismissed his appeal against SPL Powerlines. It distinguished a qualifications body’s competence standard from its assessment process. It did not give every prescribed user permission for safety-critical work or finally find all respondents liable.

Disclose enough for an assessment if you need adjustments or your medicine affects safety. Check the policy’s reporting duties; unrelated medical history is not needed. Non-disclosure is not automatically dishonesty, and employer knowledge can arise without a request. A private place to take medication may be reasonable in your case, but is not a universal entitlement.

For work driving, discuss the THC limit and medical defence with your prescriber. Never drive while impaired. An employer can temporarily remove driving duties to assess safety; continuing restrictions should reflect evidence and disability duties. Check your fleet policy and our driving guide.

Addiction, impairment and support: conduct or capability?

Did you break a rule? Are you fit to work? Is dependency affecting attendance or performance? Your employer may need to investigate conduct and assess health in the same case. A positive test does not settle those questions.

Assess the actual task: a health or care worker with patients, a cleaner using chemicals, a retail worker near machinery, a kitchen porter by hot equipment, a warehouse picker or delivery driver. Do not assume impairment from job title or test alone.

The GB disability regulations generally exclude addiction as an impairment, except addiction originally caused by medically prescribed drugs or treatment. Depression, chronic pain or another condition may qualify separately. The exclusion does not make all health consequences irrelevant or require an employer to overlook a safety breach.

Illness preventing work may qualify you for Statutory Sick Pay; rehab attendance alone does not. From 6 April 2026, SSP is the lower of £123.25 a week or 80% of average weekly earnings, from the first qualifying day, with no lower earnings limit, for up to 28 weeks. Eligibility and notification rules still apply. Check contractual sick pay and our SSP guide.

Fair discipline and dismissal

A failed test is not automatically gross misconduct. A handbook can identify serious breaches, but its label does not settle whether dismissal is fair or whether dismissal without notice is justified. In Great Britain, conduct and capability are potentially fair reasons under the Employment Rights Act 1996. The employer must still act reasonably in the circumstances.

For GB misconduct, the Acas Code requires investigation, written allegations and evidence, a hearing, accompaniment and an appeal. Check sample handling, cut-offs, confirmation, medication and medical interpretation; for breath tests, check the device and policy threshold. Tribunals can adjust relevant compensation by up to 25% for unreasonable Code failures. Pure ill-health capability needs a fair medical process, but the Code and uplift do not necessarily apply. See disciplinary procedures.

If gross misconduct is established, dismissal without notice may be justified, but the employer should still follow a fair process. Otherwise, notice or payment in lieu may be due. Keep the result, policy, prescription evidence and correspondence, and use the appeal. See gross misconduct and notice periods.

As at 1 October 2026, ordinary unfair-dismissal claims normally require two years’ continuous employment in Great Britain or one year in Northern Ireland. Some automatically unfair reasons, including certain health-and-safety dismissals, require no qualifying service. Disability discrimination also has no ordinary unfair-dismissal service threshold. See unfair dismissal eligibility.

For GB dismissals from 6 April 2026, capped weekly pay of £751 gives a maximum basic award of £22,530. The ordinary compensatory ceiling is normally the lower of £123,543 and 52 weeks’ gross pay. Exceptions apply; discrimination compensation has no such cap. These are ceilings, not promised payments. Annual award-limit increases are separate from the Employment Rights Act 2025 reforms.

Do not fight this alone. Ask Unite in hospitality, GMB in logistics or warehousing, UNISON in care or health, or USDAW in retail for union support. Acas advises on early conciliation; Citizens Advice and law centres can help. Report unsafe practice to the HSE and disability discrimination to the EHRC. Keep copies. Ask for deadline advice now.

Where the UK differs

Scotland follows GB employment rules and Acas, with lower drink-drive limits. Northern Ireland uses separate employment legislation, the Labour Relations Agency Code, the Disability Discrimination Act 1995 and HSENI. Its usual unfair-dismissal service requirement is one year. The GB specified drug-driving limits do not apply, but driving while unfit through drugs remains unlawful.

GB dismissal and tribunal reforms do not change Northern Ireland’s rules. SSP differs: nidirect confirms day-one payment and refers readers to GOV.UK. See Northern Ireland employment law.

What is in force and what is scheduled?

We have used the law and official timetable as at 1 October 2026. The government’s September timeline distinguishes changes already made from future measures. Future dates remain subject to parliamentary processes.

1. 6 Apr 2026In force: SSP changes

   The waiting period and lower earnings limit were removed. SSP is the lower of £123.25 a week or 80% of average weekly earnings.

2. 1 Oct 2026In force: longer GB tribunal time limits

   The government confirms an increase from three to six months. The change for breach-of-employment-contract claims in Scotland is scheduled for 9 November 2026. Northern Ireland’s usual time limit remains three months.

Get prompt advice on your deadline and contact Acas about early conciliation. Do not count from when you decide to claim. The timeline does not establish whether an older event gets the extended limit, and an internal appeal is no reason to delay. Ask your union, Citizens Advice or a law centre for help with the calculation. See tribunal claims.

Questions people ask

Can you be sacked for prescribed medical cannabis?

A prescription does not prevent dismissal or excuse unsafe work. But a positive result alone does not establish fairness. Ask for medical interpretation and assessment of your duties, including reasonable adjustments for disability.

Do you have to disclose your prescription?

Not every medicine must be disclosed. Check the policy, report safety-relevant effects and provide enough information for any adjustment. Keep unrelated medical details private.

Can you refuse a drug or alcohol test?

You can refuse a workplace sample, but refusal of a justified test may be misconduct. Explain your objection and request the policy and safeguards. Dismissal is not automatic.

Does a positive test prove you were impaired?

No. In Truman, the urine result showed past consumption, not current impairment. What your result proves needs qualified interpretation. Ask about confirmation and declared medication.

Is addiction a disability?

In GB, addiction itself is generally excluded unless originally caused by prescribed drugs or treatment. Other conditions may qualify. See dismissal because of illness.

Can you drive for work while using prescribed cannabis?

Never while impaired. Following medical directions may provide a defence to the specified blood-limit offence, not driving while unfit. Your employer must still assess safety and any disability duties.

Sources

1. Managing drug and alcohol misuse at work, HSE, including its guidance on safety duties and screening.
2. Screening and testing for drugs and alcohol, HSE.
3. Drug penalties, GOV.UK.
4. Misuse of Drugs (Amendments) Regulations 2018 and Misuse of Drugs Regulations 2001, regulation 16A, legislation.gov.uk.
5. Drink-drive limit and Drugs and driving: the law, GOV.UK.
6. Drug Driving (Specified Limits) (England and Wales) Regulations 2014 and Drug Driving (Specified Limits) (Scotland) Regulations 2019, draft instrument, legislation.gov.uk.
7. Transport and Works Act 1992 and Railways and Transport Safety Act 2003, legislation.gov.uk.
8. Truman v SPL Powerlines UK Ltd and others [2026] EAT 54, Employment Appeal Tribunal, judgment dated 1 May 2026. See paragraphs 38 to 40, 91 to 95 and 107 to 115.
9. Equality Act 2010 (Disability) Regulations 2010, regulation 3, legislation.gov.uk.
10. Medical examinations and drugs and alcohol testing, ICO.
11. Statutory Sick Pay: full guide, GOV.UK; Sick pay rights, nidirect.
12. Acas Code of Practice on disciplinary and grievance procedures, Acas.
13. Employment Rights Act 1996, including sections 98, 108 and 124; Employment Rights (Increase of Limits) Order 2026, legislation.gov.uk.
14. What to do if you are unfairly dismissed, nidirect.
15. Plan to Make Work Pay and Employment Rights Act: timeline update, GOV.UK, updated 25 September 2026.
16. Truman v SPL Powerlines UK Ltd and others [2026] EAT 54, Employment Appeal Tribunal, 1 May 2026.
17. Unfair Dismissal factsheet, Department for Business and Trade and Ministry of Justice, tribunal award figures for 2023/24.