Impairment tests should be core part of drug and alcohol policies

Source: OHS Alert (subscription service) (https://www.ohsalert.com.au/) (26.02.2025) 

As the use of medically prescribed cannabis grows rapidly in Australia and New Zealand, a new guide suggests employer policies should focus more on assessing impairment, including through emerging technologies, rather than simply detecting substances.

The 47-page guide, developed by the New Zealand Drug Foundation in conjunction with global law firm Dentons and Construction Health and Safety NZ, provides an overview of medicinal cannabis and suggests practical changes to workplace policies and procedures to manage disclosures of medicinal cannabis use and workplace impairment.

The issue is a thorny one for employers in both Australia and New Zealand, encompassing workplace health and safety, employment, discrimination, and privacy laws.

So far in Australia there have been only a handful of Fair Work Commission decisions dealing with the use of medicinal cannabis (see this related article, for example), but lawyers and a number of state parliamentary inquiries (see related article) have suggested employers should approach the substance in the same way as other prescribed drugs with the potential to cause impairment, when drafting and enforcing WHS policies.

The New Zealand guide follows this approach, noting that clear workplace policies setting out the duties and responsibilities of both employers and employees are crucial.

These include the duty of employees to disclose their use of medicinal cannabis, it says.

Meanwhile, employers must have a clear statement of the process to be followed after disclosure, including how employees will be supported to remain working and employed, in circumstances where there are no risks to health and safety that cannot be reasonably mitigated.

"Implementing or maintaining a workplace culture where people feel comfortable and confident to disclose that they may be impaired, regardless of the cause, will go hand in hand with a robust workplace policy," the guide adds.

The guide also stresses that drug testing policies should look to assessing impairment rather than over-focusing on detecting specific drugs.

"We think the best practice in New Zealand safety-sensitive workplaces will be in detecting impairment regardless of the cause," Construction Health and Safety New Zealand chief executive Chris Alderson said on the launch of the guide.

"Emerging technologies, including mobile apps, are showing promise in this area, and can work in tandem with drug testing where needed," he said.

The guide names two apps on the market that purportedly "measure for cognitive and motor impairment that may be due to a range of factors".

In both Australia and New Zealand, medicinal cannabis must be prescribed by a medical practitioner, and workplace polices should require employees in safety-sensitive roles to disclose its use and provide evidence that it has been lawfully prescribed, specialist workplace lawyer Renee Kasbarian told a 2024 webinar, hosted by OHS Alert's associate publication HR Daily (the recording has been temporarily unlocked for OHS Alert subscribers).

She added that where employees do disclose they have been prescribed medicinal cannabis, employers should consider seeking the worker's permission to discuss with the treating doctor whether any impairment could result and whether any adjustment to the employee's work might be required.

Kasbarian, a Henry William Lawyers partner, said that rather than including specific drugs, workplace policies, and potentially employment contracts, should require the disclosure of any medical issue that might affect workplace safety, including the use of any substance that might cause impairment.