The legal issues which arise from the dismissal of employee for contraventions of their employer’s drug and alcohol policies is vexed and difficult to apply.
In Trevor Purves v Queensland Rail Transit Authority T/A Queensland Rail  FWC 3343 a Queensland rail track worker whose employer had a zero tolerance policy to the presence of alcohol in an employee’s body and had terminated his employment was ordered to be reinstated to his job despite presenting for work with a very small of alcohol in his body. In doing so the Fair Work Commission recognized that the employer’s policy was consistent with Queensland’s rail safety laws on the subject of fitness for work and the employer being engaged in a safety critical industry and there was thus a valid reason for the employee’s dismissal but held that the dismissal was nevertheless relevantly harsh, unjust and unreasonable due to the employee’s particular circumstances including his age, re-employment prospects, unblemished work record and that he had consumed no more alcohol than he normally did and had been tested many times before without returning a positive result in those circumstances.
In contrast the Commission routinely supports employers who dismiss employees for even the slightest and most technical of contraventions of drug and alcohol policies particularly in safety sensitive industries; see for example Matthew Wyss v Omnigrip Direct Pty Ltd (2022) December 2022 and Hancock v DP World Brisbane Pty Ltd (2022) FWC 1406.
For a more detailed analysis of this issue see an excellent article published by Holding Redlich, lawyers, who are fine employment lawyers, which can be accessed at https://www.mondaq.com/australia/employee-rights-labour-relations/1348558/employers-beware–zero-tolerance-policy-does-not-automatically-warrant-dismissal?email_access=on