12 October 2022

By Rhys Evans, MD at ALCO-Safe

A sober workforce is both a legislative and an operational requirement. Employers have a duty to ensure a safe working environment, which includes a duty to prevent intoxicated persons from entering the workplace.

This is especially important in industries such as construction, manufacturing, mining and transport, where operating heavy machinery under the influence of intoxicating substances can be extremely dangerous. Workplace testing of existing employees has been used successfully to identify and deter intoxication in the existing workforce. To extend this deterrent effect and communicate a zero tolerance to substance misuse, it is advisable for companies in safety-critical industries to conduct pre-employment substance testing so as to avoid hiring individuals who are likely to defy or ignore company policies that prohibit the consumption of intoxicating substances. A clearly communicated policy that details the company’s position on alcohol and other intoxicating substances is a necessary starting point for the enforcement of occupational health and safety rules. Such a policy must detail how and when employees will be tested for substances – either on a random basis of suspicion, or regularly. In safety-critical industries, workers are usually tested for alcohol and in some instances, random drug testing, before they clock in to start a new day, and when returning from lunch breaks. However, drug testing is not that common and is usually done on suspicion. This is standard operating procedure to keep existing employees from misusing substances, but what about new or potential employees? These individuals should be thoroughly screened too. Along with the interview and a background and references check, a substance test should form part of the recruiting and on-boarding processes.


Where companies need to increase their headcount, it is critical to ensure that they are not unknowingly hiring individuals who will pose a threat to the sobriety and productivity of the workforce in place. Pre-employment testing should be included in every workplace policy on substance misuse and clearly communicated in the job advert. Applicants must be informed that if they wish to proceed with the recruitment process for this position, they will be required to submit to an alcohol and drug test during the interview process.


The most common way to conduct such pre-employment testing would require the applicant to submit to a multi-panel screening test, which is usually a six, seven or ten-panel urine test. A urine test is preferable over a saliva test, as a saliva test can only indicate the presence of substances consumed in the last few hours, while a urine test has a greater window of detection, making it possible to see if the applicant has used any substances in the past few days. For a person with a substance misuse problem, stopping consumption for at least a week before the interview and the test would be difficult. Such urine tests look for the presence of amphetamines, methamphetamines, opiates, Tetrahydrocannabinol (THC) and benzos, among other substances. Some companies are looking for a greater range of substances, seeking to avoid hiring individuals with a prescription medication problem.


It is particularly important for both employers and potential employees to note that pre-employment testing is something that is well within the employer’s rights to enforce. The Occupational Health and Safety Act states that employers can take reasonably practical measures to ensure that intoxicated people are prohibited from entering the workplace. It is also important to be aware of the fact that workplace policies supersede personal privacy rights, in respect of alcohol and substances. A recent high court judgment indicated that while the use of cannabis has been decriminalised by the Constitutional Court in an individual’s private life, this does not provide a defence for failing to comply with workplace rules that require a clean result from substance testing. It also does not matter if the individual is not impaired at the time of testing positive for a substance such as THC (the active ingredient in cannabis), what takes precedence is that there is a policy in place, the employee is aware of the policy, and the employee had previously worked in compliance with the policy.


In light of a dangerous working environment, a company is entitled to enforce its zero-tolerance policy and the Constitutional Court judgment does not offer any protection to employees against disciplinary action should they breach company policies. In this high court case, a long-serving employee was fired after repeatedly testing positive for cannabis, in breach of the company’s rules. The individual approached the high court for relief, requesting that she be reinstated and that such a dismissal was unfair because she relied on the substance for medicinal purposes. The high court dismissed her application, stating that she had been treated the same way as any other employee and if she were treated differently, it would inevitably create a precedent that placed an unfair burden on the company.


This high court judgment confirmed that as long as there is a fair policy in place, written within the bounds of the law, that policy must stand. Accordingly, for pre-employment testing, as long as it is clearly communicated, then the individual has the opportunity to choose whether or not they wish to comply with the testing requirement, but failure to do so will preclude them from employment at that particular company. Bearing in mind that the ultimate goal is not to catch people out and punish them, but to proactively identify substance misuse and ensure a sober workforce. As such, pre-employment testing can and should be used to communicate and enforce a zero-tolerance policy in dangerous industries.

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