Buying test kits is easy. The hard part comes later, when a test result is challenged at a disciplinary hearing, an employment tribunal or in a conversation with a union representative. At that point the cup and the cassette count for very little. What matters is whether everything around them stands up: the policy, the consent, the procedure and the competence of the people who ran the test.
Why it matters
Employers already have a general duty under the Health and Safety at Work etc. Act 1974 to protect employees and others. The Management of Health and Safety at Work Regulations 1999 also require a suitable and sufficient risk assessment. Where people drive, operate plant, work at height or look after others, impairment through drink or drugs is a foreseeable risk. Some sectors carry specific legal duties as well. In rail and tram operations, for example, the Transport and Works Act 1992 makes it a criminal offence for certain workers to be unfit through drink or drugs.
Testing is one control among several. On its own, it is not a policy.
Five things a defensible policy needs
1. A clear reason for testing. Say why you test and who is covered, and link it to your risk assessment. Testing safety-critical roles is easy to justify. Testing everyone, everywhere, with no reasoning behind it is much harder to justify.
2. Consent and contract. Nobody can be lawfully tested without their consent. The policy should be part of the terms of employment, explained at induction and agreed in writing. The policy should also explain what happens if someone refuses a test.
3. Data handled properly. Test results are health information, and UK GDPR treats health data as a special category. Limit who sees results, keep them secure, keep them only as long as you need to, and complete a data protection impact assessment before you start testing.
4. A sound procedure. A screening test is a screen, not a conviction. A non-negative result needs confirmation by an accredited laboratory, with a documented chain of custody from the sample to the report. The person being tested should be told about their rights at each step and given the chance to declare any medication.
5. Competent people. Whoever collects the sample has to follow the procedure exactly, every time. Most challenges succeed because a step was skipped, not because the result was wrong. Train your collectors, assess them, and authorise them in writing.
Support as well as discipline
A good policy separates someone who asks for help from someone who is caught. Encourage people to come forward before an incident, offer support for dependency, and say clearly how the business will respond. Fairness here protects both the person and the business if a case reaches a tribunal.
Where PMSCS helps
PMSCS writes and reviews drugs and alcohol policies. It also delivers the Competence in Workplace Drugs and Alcohol Testing course, which follows four steps: training, assessment, demonstrated competence and organisational authorisation. Your collectors finish the course with more than a certificate. They come away with evidence that they can do the job properly.
This article is general guidance, not legal advice. Take specific advice for your own circumstances.