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Safeguard Magazine

Cannabis: Testing: not weeded out

Would legalisation of recreational cannabis use mean the end of workplace testing for it? Not so fast, says AMANDA DOUGLAS.

The landscape is changing, with medicinal cannabis now legalised and an upcoming referendum testing the appetite for the legalisation of personal use of cannabis. So, what is the impact on drug testing in the workplace, and the systems that employers already have in place?

The Misuse of Drugs (Medicinal Cannabis) Regulations 2019 came into force in April. These regulations allow individuals to obtain a prescription for medicinal cannabis from their doctors. Although the legislation initially proposed the need for a specialist sign-off, the regulations, now in place, allow all general medical practitioners to prescribe medicinal cannabis to their patients.

This is an important development that employers need to be aware of, as employees could now be validly using medicinal cannabis.

However, the floodgates will not be opened to allow unregulated use of medicinal cannabis. First, the use of medicinal cannabis is heavily regulated, and second, by definition, medicinal cannabis does not contain THC and is not psychoactive, meaning that those taking it will not be “getting high”.

There is also a push for change in relation to recreational cannabis. Voters at the September referendum will be asked to vote “yes” or “no” to the question of whether they support the proposed Cannabis Legalisation and Control Bill. That Bill allows for personal possession (up to 14 grams of dried cannabis), purchase and use of cannabis by persons 20 years or older. Cannabis could only be used in private residences or specially licenced/regulated consumption places.

All employers who drug test employees will be affected by the medicinal cannabis regulations and, possibly, by the outcome of the referendum. It will be important for employers to review current drug and alcohol policies to ensure their policies reflect the legalisation of medicinal cannabis use, and (dependent on the referendum results) potentially the recreational use of cannabis. For employers who do not have drug and alcohol policies, it will be more important to introduce policies that clearly outline how the business will approach these issues.


Currently, cannabis is one of the drugs that employers test for. Employers in safety sensitive industries regularly conduct drug tests on their employees, for health and safety reasons. The presence of cannabis above a specified level generally constitutes a failed drug test. Dependent on an employer’s policies, a failed drug test can lead to disciplinary action up to and including dismissal.

In a pre-employment drug test, the presence of cannabis may be grounds to withdraw an offer of employment.

When taking a drug test, employees ordinarily have to declare the prescription medicines that they are taking. Medicinal cannabis is now one that employees will need to declare. If an employee does not declare the use of a prescription medicine and it shows up in the test results, the employer has grounds to start a disciplinary process over the failure to declare that substance, particularly where it can affect safety.

Also, employees are often required to disclose medical history or current medical issues that might impact their ability to perform in their role, so the underlying medical condition may, in fact, be something that needs to be disclosed to the employer.


Employers are already asking how drug testing in the workplace will be affected if recreational cannabis is legalised; in particular, whether testing will still be allowed.

The short answer is: yes. We need to look at why employers drug test. It is not because it is illegal, but because of the impact on safety and health. Despite any legalisation, the safety concerns about drug use affecting employees in the workplace remains the same. Those who work in safety sensitive environments remain a health and safety risk to themselves and others. Legalisation will not change those effects.

If recreational use of cannabis is legalised following the referendum, it is useful to draw an analogy with alcohol consumption now. While it is legal for employees to drink alcohol in their own time, employers do not permit employees to show up to work under the influence of alcohol. The same would apply in respect of recreational consumption of cannabis. Drug testing can, therefore, continue.


Of course, any legalisation may change the focus from whether cannabis is present in an employee’s system (as is currently tested) to whether the cannabis has impaired the employee. This is a fraught topic, as cannabis can remain present in an employee’s system for several weeks after they have consumed it. This could mean an employee is at work with cannabis in their system but not necessarily impaired by its presence.

Presently, there is no mainstream test for impairment in New Zealand, although we are told that saliva testing will assist with this. We may see methods of testing evolve so that employers are able to test for impairment of the individual, as opposed to simply measuring the level of cannabis present.

Until such methods are available, employers will need to ensure they have robust policies in place with processes to fall back on that are fair and reasonable, taking into account the potential that cannabis may be legalised for recreational use.


If recreational use is legalised, employers will need to take care when enforcing drug and alcohol policies and testing employees. All employers who drug test their employees will need to look at their current policies and consider their stance on both medicinal cannabis consumption and recreational cannabis consumption (if it is legalised). It is safe to say that most policies will need to be updated.

The introduction of these measures should not stop employers from drug testing their staff. To the contrary, if there is legal access to cannabis, it will become even more important that employers have up-to-date processes and that they are monitoring their employees through testing.

Amanda Douglas is a partner specialising in employment and health & safety at Wynn Williams Lawyers.

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