Drugs and Alcohol at Work — Writing a Policy for Your Trade Business (2026)

Why Drugs and Alcohol Matter on a Trade Site

Trade work concentrates exactly the hazards where impairment is most dangerous. Power tools, circular saws and angle grinders demand split-second reactions. Excavators, telehandlers, dumpers and other plant put a heavy machine in the hands of a single operator. Working at height — scaffolds, roofs, ladders, MEWPs — leaves no room for a lapse in balance or judgement. And many trade workers drive vans, tippers or HGVs as part of the job, where alcohol or drugs in the system is both a safety risk and a criminal offence.

Impairment slows reaction time, impairs coordination, reduces risk awareness and increases the chance of an error that on a building site can be fatal. Alcohol consumed the night before can still leave a worker over the limit the next morning. Cannabis and other drugs can remain detectable and impairing well after use. Even legitimate medication — antihistamines, strong painkillers, some cold remedies — can cause drowsiness that is dangerous around machinery. A policy that addresses all of these is not box-ticking; it is part of keeping people safe.

The Legal Duties — What the Law Requires

Several pieces of UK legislation bear on drugs and alcohol at work. You do not need to be a lawyer, but you should understand the framework so your policy stands on solid ground.

Health and Safety at Work etc. Act 1974

This is the cornerstone. Under section 2, you as an employer have a general duty to ensure, so far as is reasonably practicable, the health, safety and welfare of your employees. Knowingly allowing an impaired worker to carry on working — operating machinery, driving, working at height — would breach that duty. Section 7 places a parallel duty on employees to take reasonable care of their own safety and that of others affected by their work, and not to be a danger through their own conduct. A worker who turns up impaired is in breach of their own legal duty as well as yours.

Management of Health and Safety at Work Regulations 1999

These regulations require you to carry out a suitable and sufficient risk assessment of the risks to health and safety in your business. Where drugs and alcohol could reasonably foreseeably contribute to a serious incident — which on most trade sites they could — your risk assessment should consider that risk and the controls you put in place to manage it. A written policy is one of those controls.

Misuse of Drugs Act 1971

This Act makes it an offence to knowingly permit or suffer the production, supply or use of controlled drugs on premises you occupy or manage. If you become aware that drugs are being used or dealt on your site or in your premises and you do nothing about it, you could be committing an offence. Your policy should make clear that controlled drug activity will be reported to the police where appropriate.

Transport and Works Act 1992

For safety-critical transport roles — for example certain rail, tram and guided-transport work — this Act makes it an offence to carry out specified duties while unfit through drink or drugs, and places a duty on operators to take all reasonable steps to prevent it. If any of your work falls under safety-critical transport rules, testing and tighter controls are effectively mandatory rather than optional.

Drink and Drug Driving Law

Anyone who drives for work — vans, tippers, plant on the public highway — is subject to the Road Traffic Act drink-drive limits and the separate drug-driving offence, which sets specified limits for a list of controlled drugs (including limits set very low for illegal drugs). It is an offence to drive, or attempt to drive, while over the limit or impaired. Where staff drive for you, your policy must address this directly.

Quick Reference: What a Drugs & Alcohol Policy Should Contain

How to Write and Implement the Policy

A policy that sits in a drawer achieves nothing. To be effective — and to stand up if you ever have to rely on it in a disciplinary case — it needs to be clear, fair and properly introduced. The steps below work for a small firm without an HR department.

Consult Your Staff

Talk to your team before you finalise the policy. Explain why you're introducing it — safety, not surveillance — and give people the chance to ask questions. Consultation builds buy-in and reduces the sense that the policy is being imposed. If you have a union or employee representatives, involve them. A policy that staff understand and accept is far more likely to be followed than one that lands as a surprise.

Make It Clear and Fair

Write in plain English. State clearly what is prohibited, what will happen if the rules are broken, and how the policy is applied to everyone equally. The same rules should apply to the owner and the apprentice alike — a policy that is seen to be applied selectively loses all credibility. Set out the standards, the consequences and the support available, and make sure every worker has a copy and signs to confirm they have read it.

Cover Prescription and Over-the-Counter Medication

This is the part small firms most often miss. Some prescription and over-the-counter medicines cause drowsiness or affect coordination and reaction time. Your policy should ask workers to check the label and ask their pharmacist or GP whether a medicine affects their ability to do safety-critical work, and to tell you (in confidence) if it does. You can then decide together whether to move them to lower-risk duties while they take it. Treat this as a safety conversation, not a disciplinary one — workers must not feel they have to hide legitimate medication.

Define Testing — If You Use It

Testing is not mandatory for most trade firms, but many choose to include it, and some principal contractors require it. If you test, your policy must say when and how. Common triggers are:

• With-cause: testing where there is a reasonable suspicion of impairment based on observed signs
• Post-incident: testing after an accident or near miss, as part of the investigation
• Random: unannounced testing of staff selected at random, used by some employers as a deterrent

Testing needs the worker's informed consent, and the policy should explain what a refusal means. Results are health information — special-category personal data under UK GDPR and the Data Protection Act 2018 — so you must have a lawful basis to process them, keep them confidential, share them only with those who genuinely need to know, and store and dispose of them securely. Use a reputable, accredited testing provider so the procedure and chain of custody stand up if challenged. Do not improvise testing with a kit off the internet.

Spotting Signs of Impairment

Supervisors should know what to look for. Possible signs include the smell of alcohol, slurred speech, unsteadiness, bloodshot eyes, mood swings, unexplained lateness or absence, a drop in work quality, and uncharacteristic mistakes around tools or machinery. None of these alone proves impairment — many have innocent explanations, including illness or fatigue — so train supervisors to raise a concern calmly, remove the person from safety-critical work while it is looked into, and follow the policy rather than jumping to conclusions or accusing someone on the spot.

Balance Discipline With Support

A drugs and alcohol policy should do two things at once: protect safety, and recognise that dependency can be a genuine health problem. Where a worker comes forward, or where a problem emerges, treating dependency as a health issue — offering support, time to seek help, and a route back to work — is both the humane response and often the one that resolves the situation. Many employers signpost to their GP, occupational health, or charities and support services. Keep this support route separate, in the policy, from the disciplinary process: a worker who turns up impaired and refuses help is a conduct matter, but a worker who discloses a dependency and engages with treatment should be supported. Be clear, though, that the support route does not give a free pass to ignore safety rules.

Site Rules and Inductions on Larger Contracts

If you take on subcontract work for a principal contractor — a main builder, a housebuilder, or a commercial site — expect them to require a drugs and alcohol policy as a condition of working on their site. Many large sites operate their own rules, run inductions that cover drugs and alcohol, and carry out testing (with-cause, random or as part of induction). Having your own policy in place means you can sign up to those site rules without scrambling, and it shows the principal contractor you take safety seriously. Make sure your own staff and any labour you bring on understand that the site's rules apply to them and that a positive test or refusal can mean removal from site.

Record-Keeping

Keep a record that each worker has received and read the policy, that supervisors have been briefed, and of any incidents, concerns raised, decisions taken and support offered. If you ever face a dismissal claim, an HSE investigation or a query from a principal contractor, those records show you acted reasonably and consistently. Where records contain health information — such as test results or details of medication or dependency — handle them as confidential special-category data: limit access, store them securely and keep them only as long as you need them.

Keep It Practical for a Small Firm

You don't need a 40-page corporate document. For most small trade businesses a clear two- to four-page policy is enough: why it exists, what's prohibited, the rules on medication, whether you test and how, the support available, the consequences, and a signature line. Build it into your induction so every new starter reads and signs it on day one, review it every year or two, and update it if the law or your sites' requirements change. The goal is a policy people actually understand and follow — not a binder nobody opens.

The Bottom Line

A drugs and alcohol policy is one of the cheapest and most effective safety controls a trade business can put in place. It clarifies the rules, protects your workers and the public, helps you meet your legal duties under the Health and Safety at Work etc. Act 1974 and related law, and gives you a fair, consistent basis for acting when something goes wrong. Write it in plain English, consult your team, cover medication and testing properly, balance discipline with support, and keep the records to prove you mean it.