Positive weed test not a good enough reason for dismissal, Fair Work says

A worker who allegedly contravened his company’s cardinal drug rule by testing positive for cannabis has won an unfair dismissal claim.

A man was terminated on 15 September 2025 after his employer asserted that he was “under the influence” of cannabis, or THC, in August 2025, during a job that required him to drive to and perform work in NSW’s central west.

In a 23 March 2026 decision, Fair Work Commission deputy president Tony Slevin ruled his dismissal was harsh and unfair, rejecting the employer’s assertion that the employee had contravened “cardinal rule 10” of its drug policy.

Slevin preferred the employee’s evidence that he was not a regular user of cannabis and that his consumption of the drug was out of character.

He concluded the man was not under the influence on the job.

The commission approved the employee’s unfair dismissal claim and ordered his employer to grant him reinstatement and compensate him for lost wages.

The man commenced employment with Downer EDI Works (Downer) and its predecessors in 1998 and went on to work in a range of roles during his tenure, including traffic controller, plant operator, leading hand, and depot manager.

At the time of his summary dismissal on 15 September 2025, he had been working as an area supervisor for 12 years.

During a Friday night dinner party, he smoked a cannabis cigarette that was provided to him by a guest.

On Sunday, the employee undertook an over-the-counter urine test, which came out negative for THC. The employee formed the belief that he was fit for work the next day from his test result.

During the next workday, Downer required the employee to undergo another drug test, which came out with a non-negative result for THC.

On 28 August 2025, Downer issued him a show cause letter for serious misconduct arising from this test result. He responded the next day.

In this response, the employee admitted to consuming cannabis as alleged, but said that he believed that he was fit for work based on his self-test result.

After consideration of his response, Downer terminated him with immediate effect on 15 September 2025 for his contravention of its drug policy, citing the company’s “cardinal rule”.

The commission viewed expert evidence that revealed visible THC metabolites in his urine sample on 25 August 2025; however, Slevin found that this “only proves previous cannabis use, not that someone is currently impaired or intoxicated”.

The deputy president accepted his assertion before the commission that “using cannabis at the social gathering was out of character for him and not a regular habit”.

“I am satisfied based on the expert evidence in the proceedings that while [he] was over the cut-off level for the confirmatory test, he was neither intoxicated nor impaired to work at the time of the test,” the deputy president said in his judgment.

“I note again that the expert evidence was that it was unlikely that [he] was impaired at work. I find that he was not.”

After considering available evidence, Slevin ruled the dismissal unfair, citing his 27 years of unblemished service.

Slevin rejected Downer’s assertion that a loss of trust and confidence in the employee had formed, and he determined reinstatement as an appropriate remedy.

In his 23 March 2026 decision, Slevin ordered Downer to reinstate the employee within 14 days and provide compensation for lost wages for the period from dismissal to reinstatement.