Updating your drug and alcohol policy for medicinal cannabis
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More than a million Australians have been prescribed since 2016. If your policy predates that reality, it will eventually be tested by a disclosure, a non-negative result, or a tribunal — usually in that order. Here is what a defensible update contains.
1. Name prescription medication — and medicinal cannabis — explicitly
Policies that only contemplate illicit use leave managers improvising when a lawful prescription appears, and improvisation is where discrimination risk lives. State plainly that the policy covers prescription, over-the-counter and illicit substances, and address medicinal cannabis by name, including that THC-containing products can return non-negative results regardless of lawful use.
2. Choose your standard: cut-offs, impairment, or both — and say so
The Commission upheld DP World’s dismissal partly because the policy honestly set cut-off limits and did not pretend to measure impairment. Whichever standard you adopt, draft it explicitly: the testing method, the applicable Australian Standard, the cut-offs, and what exceeding them means. Vague hybrids — impairment language enforced as detection — are where policies die in cross-examination. See impairment vs detection.
3. Make disclosure an ongoing, specific duty
The single most decisive clause in the case law. Require disclosure of any medication that could affect safe performance — to a named role, in writing, before commencing affected duties, and renewed whenever the prescription changes or resumes. Mills (disclosed cannabis, not THC) and Haigh (resumed without re-disclosing) both turned on the gap between one-off and ongoing disclosure.
4. Define what happens after disclosure
A policy that jumps from disclosure straight to discipline invites discrimination claims. Build in a documented fitness-for-work assessment: role risk, product and THC content, dosing timing, medical input, and consideration of adjusted duties where reasonably practicable. That documentation is simultaneously your safety case and your discrimination defence — the Policy Pack’s risk assessment template structures it.
5. Guarantee process integrity
- Confirmatory laboratory testing before any disciplinary decision — screening results alone are indicative.
- Kits and procedures matched to the standard named in the policy (the 2025 mining matter in our tracker shows what a 2006/2019 standards mismatch does to your evidence).
- Privacy handling for medical information — see the privacy guide.
- Procedural fairness in discipline — see the process guide.
6. Consult, train, and date the review
WHS law expects consultation on policies like this, and consultation also produces disclosure instead of concealment — which is the outcome you actually want. Train supervisors on the manager conversation (what to say when someone discloses; what never to say), and put a review date on the document: this area is moving quarterly.