Drug testing in the Irish workplace is one of those topics that throws up a multitude of considerations for employers. In the absence of a clear statutory framework, employers must assess and grapple with overlapping and competing factors, including employee wellbeing, health and safety obligations, constitutional rights, equality concerns, data protection issues and workplace culture. 
 

What does the law say?
While the Safety, Health and Welfare at Work Act 2005 (the “SHW Act”) envisages regulations for testing, these have never been enacted, meaning the subject remains a matter of contract and policy, not statutory compulsion. The SHW Act, does, however, place a number of obligations on employers and employees alike, including:

• Section 8 requires employers, so far as reasonably practicable, to ensure the safety, health, and welfare of employees.
• In addition, sections 19 and 20 impose obligations on employers in respect of hazard identification, risk assessment and safety statements. Employers must identify workplace hazards, complete a risk assessment in relation to those hazards and prepare a safety statement. Intoxicants (defined by the SHW Act as alcohol, drugs, and any combination thereof, including prescription and over-the-counter medication) may constitute a workplace hazard and accordingly, where identified as such, should be included in an employer’s risk assessment and safety statement.
• Section 13, on the other hand, places an obligation on employees to comply with all relevant statutory provisions and take reasonable care to protect themselves and others at work. This includes avoiding impairment and cooperating with safety measures. For example, employees must not work under the influence, to the extent that they endanger themselves or others, and must cooperate with employer policies.
   

When is testing permitted?
While testing may not be legally mandated under Irish law, it may be permitted where an appropriate framework is implemented. As a general rule, employers can introduce testing policies where they are reasonable, proportionate, and necessary for safety, particularly in safety-critical roles. Given that test results may constitute sensitive personal data, employers will need to be mindful that such policies must comply with GDPR and the Data Protection Act 2018. Appropriate consent is vital to a successful testing regime, and policies should be clearly communicated, consistently applied, and supported by fair procedures. 

A recent decision of the Workplace Relations Commission (“WRC”) provides a useful example of the issues that can arise with workplace intoxicant testing and the steps that employers can take to design a robust process. 
 

Recent caselaw: Philip McMahon -v- Dublin Bus
In this case, the Complainant was a bus driver with 28 years’ service with his employer, Dublin Bus. His employment was terminated following a disciplinary process that arose out of his refusal to submit to drug testing (specifically, oral swab testing) that was mandated for under a 2022 policy. The Complainant argued that his dismissal was unfair and contrary to his constitutional right to bodily integrity. He maintained that he would only submit to testing by his employer’s Chief Medical Officer under a 2016 agreement (which specified breath, blood, or urine tests).

The Respondent defended its position, citing a 2022 policy update that introduced oral swab testing for drugs and breathalyser tests for alcohol, delivered by a third-party provider. The policy was published and included clear warnings that refusal could lead to disciplinary action.
 

WRC Findings
The Adjudication Officer (“AO”) confirmed that the fact of dismissal was not in dispute, placing the burden on the employer to justify it under the Unfair Dismissals Acts. After reviewing evidence and hearing witnesses under oath, the AO found that the employer acted reasonably. The testing policy was lawful, proportionate, and had been communicated to staff. The complainant’s refusal to comply, despite multiple opportunities, amounted to gross misconduct.

The AO rejected the bodily integrity argument, holding that public safety considerations outweighed the complainant’s objections. The disciplinary and appeals process was deemed fair, and the claim for unfair dismissal was dismissed.

Implications for workplace testing and policies

This decision reinforces the view that:

• Drug and alcohol testing policies, when properly implemented, are enforceable.
• Refusal to comply with a lawful and reasonable policy can constitute gross misconduct.
• Constitutional rights arguments will be balanced against legitimate safety objectives.

This case also serves as a useful reminder of the key factors that should be taken into account when designing an effective intoxicant‑testing framework, including:

• Reasonableness & proportionality:  both the regime and the policy should be limited in nature and targeted at safety-sensitive roles or specific risks (e.g., machinery operation, transport).
• Communication and informed consent: the policy should be clear, and employees should be educated on the objective / reasons for implementing the policy in the first place. To assist in obtaining sufficiently informed consent, relevant processes and requirements should be embedded in contracts or relevant policies and clearly communicated.
• Consultation with employees/trade unions prior to implementation will enhance the likelihood of employee “buy-in” and acceptance. 

Further, policies should be:

• Clear and transparent: e.g. covering scope, testing procedures, data (storage/retention/access), confidentiality, prescription/over the counter medication and consequences for refusal or positive results.
• Fair & non-discriminatory: applied consistently to all employees in similar roles, with reasonable accommodations under equality legislation.
• Supported by risk assessment and documented in the workplace safety statement or risk management process. 
  Policies can also address the types of testing to be conducted, for example, pre-employment (for safety-critical roles), post-incident or “for-cause” testing; random testing (being truly random in nature, typically for safety sensitive roles only implemented on a  non-discriminatory basis); and “return to work” or “abstinence monitoring”.
  Employers may also wish to consider forward planning outside of disciplinary action in the event of positive testing, for example, the introduction of support and assistance for employees (e.g. in the form of counselling or rehabilitation services). 

Key Takeaways
The Dublin Bus decision suggests that the WRC will support the enforcement of robust safety-related policies, provided that a fair process is observed.

For employers and HR professionals, the case highlights the need to:

• keep policies updated and aligned with both operational realities and best practice testing methodologies;
• communicate expectations and any changes clearly to obtain valid and informed consent;
• ensure disciplinary (and any other consequences) for non-compliance are unambiguous and consistently applied.

Whether preparing a new policy or reviewing one already in place, employers should aim for intoxicant testing policies that are clear, proportionate, and GDPR-compliant. Where third-party providers are used, transparency and fairness in selection and procedure will also be critical.