Drug and alcohol testing in UK workplaces must be ‘risk-based and transparent’

Substance misuse in the workplace is emerging as one of the most difficult challenges for employers to manage and it isn’t just about recognising the problem – it’s about knowing how to manage it. For many employers, that means having the right drug and alcohol testing policy in place, one that protects safety without undermining trust. It’s a fine balance, and it’s where HR and health and safety need to work hand in hand.

The latest edition of IOSH Magazine looks at this in detail in Anna Scott’s article ‘How to Implement Drug Testing’ which explores the legal, ethical, and practical challenges of introducing testing at work. It’s an issue that sits right at the intersection of HR and health and safety – getting it wrong can damage culture and risk legal claims but getting it right can strengthen both safety and well-being. We’ll speak to health and safety lawyer Zoe Betts about what fair and proportionate testing looks like in practice. 

Anna Scott’s article makes clear that testing is not a quick fix or a disciplinary shortcut – it’s a risk-management tool that must be justified by safety concerns and underpinned by consent, transparency, and trust. She stresses that drug and alcohol testing should only take place where there is a clear business or safety reason, and that the policy must spell out when testing will occur – whether that’s pre-employment, post-incident, for cause or on a random basis. HR’s role, she says, is central: ensuring policies are lawful, proportionate, and consistently applied, and that results are handled confidentially and with care.

She also highlights the importance of communication. Employees need to understand why testing exists and how it fits within a wider health and well-being strategy. Without that understanding, even a technically compliant policy can erode trust. HR, working alongside health and safety teams, is therefore key to bridging that gap, ensuring procedures protect privacy while maintaining confidence in how testing is managed.

So, let’s get a view on this. Earlier I caught up with Zoe Betts, who joined me by video link to discuss it. So, can drug and alcohol testing it be justified, and if so when?

Zoe Betts: “Yes, drug and alcohol testing certainly can be justified. Fundamentally, employers have a duty under section 2 section 3 of the Health and Safety at Work Act 1974 to take reasonably practicable steps to safeguard the health and safety of their employees, and also their non employees – so that's people like visitors, contractors and members of the public – and in this context, we are safeguarding people from the risks that may be created by workers who are under the influence of drugs and alcohol for obvious reasons, really. They are more likely to be involved in, or create accidents because they may have poor concentration, they may have impaired judgment or slower reactions. So drug and alcohol testing is definitely justified but there does have to be a clear safety rationale. So that might be where people are in safety critical roles, they might drive for work, they may work at height or operate machinery, because if there isn't a clear business reason for undertaking the drug and alcohol testing, I would also say that that's disproportionately intrusive on the worker’s privacy and their human rights. I would also say that drug and alcohol testing should be part of a broader risk management framework, one which really tries to do two things. On the one hand, support openness and encourage people to admit they may have substance misuse issues but at the same time be very clear about outlining when and why drug and alcohol testing would take place in the workplace and that really is in four categories. It can be pre-employment, following an incident where there is reasonable cause, and it can also be done randomly.”

Joe Glavina: “There are obviously quite a few legal and ethical pitfalls HR need to be aware of. I guess consent must be one of them” 

Zoe Betts: “Yes, it absolutely is. Consent has to be contractual and it has to be explicit. So employees cannot be forced to undergo drug and alcohol testing unless there is something expressed in their contract of employment, and unless they have given their informed consent. I think one of the other pitfalls that HR and health and safety professionals can fall into in this context, is not understanding the quite onerous obligations of GDPR compliance and confidentiality. It's obviously critical that people feel that this sort of testing is being done appropriately, it’s being done to the right standards and that, of course, any sensitive personal data is going to be handled and stored very well. Ultimately, the results of drug and alcohol testing should only be seen by those on a strict authorised basis and a need-to-know basis, and if that isn't the case then I would say that testing without justification, or testing in a way which ultimately leads to a breach of privacy, can really undermine the trust and faith that employees have in their employer and that can really damage morale within an organisation because, ultimately, everybody wants to believe that they are being employed in a fair and transparent way.”

Joe Glavina: “Clearly there is a balance to be struck here, Zoe, so maintaining safety and compliance, but without damaging trust. How does HR do that?”

Zoe Betts: “Yes, I think there's a couple of ways they can do that, and communication is often key. Communication should be as open as possible. People need to understand why testing is being done. Fundamentally it's being done to maintain high safety standards in the workplace and that goes to the heart of an organisation's culture, really, but it's also about encouraging people to accept help and look for support if they've got medical issues or they're battling with addictions. So communication is definitely key to getting this right. I would also say there has to be a real trust from the workers in the reliability and the credibility of results. So if initially screening has taken place and a non-negative result has been returned, that then needs to be corroborated by a laboratory that has been UKAS accredited for the type of testing that has already been carried out. That will really instil faith, I would suggest, in the employees that the testing is being done properly and to the right standard. Then lastly, I think there's a role here for health and safety professionals to really collaborate with their HR colleagues and also management to ensure that any policy which is implemented is fair in the way that it's been drafted, is fair and consistent in the way that it's being applied in the workplace, and that appropriate equipment has been used. So that's almost going to your procurement department to make sure that the right testing equipment is being purchased and then used so that the results are reliable and not likely to be challenged. Then lastly, I would say there's a role for training. So if health and safety professionals are able to train their HR colleagues, and their line managers, as well as all of the employees on the drug and alcohol testing policy and why it's being done, I would hope that that would underpin the positive safety measures behind it, and steer people away from regarding the policy with fear and suspicion.”

That article by Anna Scott appeared in the latest edition of IOSH magazine which can be accessed online for free. We have included a link to it in the transcript of this programme for you.

- Link to IOSH magazine September/October 2025 issue