The prevalence of cannabis and its impact on the workforce, like drug driving, is already a common, and divisive issue. Under the current system drug testing is legal for those who work in a safety critical environment, however it must be part of the employee's condition of appointment. Drug testing measures currently are technically limited and often used as a punitive tool; as with driving, current drug tests do not screen for impairment; they only indicate past use, which is a major limitation. This is especially significant as cannabis has the longest detection period for urine based drug tests, which can show the presence of cannabis long after the adverse effects have gone (up to a week for single use, while habitual use lasts for several months). [i]
Testing raises two main issues:
- Gaming the system through users predicting when they will be tested, or changing their drug use to undetectable substances; and
- Users testing positive and being punished when the adverse effects are no longer present.
For these reasons, TOP advocates safety-critical workplace testing only in conjunction with observing people for impairment. Non-safety critical testing is not necessary – it is much better just to observe for impairment and respond with constructive support where a problem is identified. Research on random workplace drug testing found the chance of being detected did not change the number of people involved in incidents due to impairment from alcohol or drugs, and that testing alone is ineffective at improving health and safety.[ii] Testing on workers drug use does impact the amount of users found, but does not show a change in the number of injuries in the workplace. Therefore it can be concluded that the testing only impacted drug use that was not causing impairment in the workplace.[iii]
Air New Zealand is leading the way on this issue with drug testing considered only a very small component of a comprehensive workplace policy. Their focus has been on building a safe culture promoting peer responsibility. In their sector, self-reports and help-seeking are promoted and common.
TOP Takeaway: Again, workplace testing is already an issue. We advocate safety-critical workplace testing only in conjunction with observed impairment, as per drug driving. That way people with residual cannabis in their system who are not impaired are not unfairly punished.