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South Africa: Positive or negative, the challenge with breathalyser tests

15 June 2023
– 4 Minute Read



  • In a recent decision by the South African Labour Court, the reliability of breathalyser testing to prove the contravention of an employer’s zero-tolerance alcohol and drugs policy was called into question.
  • In the matter of Samancor Chrome Ltd (Western Chrome Mines) v Willemse and Others, the Court found that the arbitrator did not reach an unreasonable decision in finding the employee’s dismissal to be substantively unfair. The employee had tested positive for alcohol on three breathalyser tests on two different machines, but a blood test yielded a negative result.
  • In the circumstances, the arbitrator found that the employer had failed to establish that the employee breached the zero-tolerance rule.

On 29 May 2023, the Labour Court handed down judgment in the matter of Samancor Chrome Ltd (Western Chrome Mines) v Willemse and Others (JR 312/2020) [2023] ZALCJHB 150. The judgment calls into question the reliability of breathalyser testing to prove the contravention of an employer’s zero tolerance alcohol and drugs policy.

The facts

The employee was dismissed after testing positive for alcohol on three breathalyser tests conducted by the employer on two different machines. The second machine (the Lion Alcometer 500) indicated an alcohol content of 0.013%. The employee denied that he had consumed any alcohol that day or the previous night. He then went to a medical doctor who sent a blood sample to Ampath Laboratory to be tested, the results of which were negative.

The employer’s zero tolerance policy deems an employee unfit to enter the premises if their breath alcohol level exceeds 0.000%. Any positive test is considered gross misconduct, which may lead to summary dismissal.  This fate befell the employee, and he challenged his dismissal at the Commission for Conciliation, Mediation and Arbitration (CCMA).

The CCMA’s award

At the CCMA, the employee’s doctor confirmed that the employee had consulted him and that a blood sample came back negative. The employer led the evidence of a chemical pathologist who testified that breathalyser tests may be false in certain circumstances, including when the person tested had not eaten for more than eight hours, or had eaten any substance with a yeast content. However, the blood test did not mean the employee did not have any alcohol in his blood, because the method used cannot test for alcohol below 0.010g/dl. Nevertheless, for all clinical purposes, the blood result was negative and in the pathologist’s opinion the breathalyser was false/positive.

While the arbitrator acknowledged that breathalyser testing was a convenient method for the employer to use to check if an employee had alcohol in their system, he found that the chairperson of the disciplinary hearing ought to have taken the laboratory results into consideration, since those are more accurate and reliable. Accordingly, based on the evidence presented, the arbitrator found that the employee did not breach the employer’s policy. The employee’s dismissal was found to be substantively unfair and retrospective reinstatement was awarded.

Labour Court review

On review, the Court found, among other things, that the arbitrator did not misdirect himself in the assessment of any evidence. Having dismissed the employee for testing positive for alcohol in breach of its policy, the employer bore the onus of proving that there was alcohol in the employee’s blood stream.

The result of the blood-alcohol test, taken together with the expert evidence, did not definitively establish that there was any alcohol in the employee’s bloodstream and instead produced a clinically negative result.

As for the breathalyser tests, these were confirmed to be less reliable than blood tests and to be prone to give false positive results. To the extent that the employer sought to contend that it was improbable that the two breathalyser devices could have given three false results on the same date, there was no evidence presented by the employer to show how many other employees were tested on that day, and how many positive or negative results were generated. Therefore, the evidence presented at arbitration supported the arbitrator’s assessment of the probabilities and his findings.

The employer’s review application was accordingly dismissed, with costs.

Key take aways

While it is generally accepted that breathalyser tests are a convenient way for employers to test compliance with their alcohol and drugs policies, it is also trite that they are not always reliable. Therefore, where their results are contested by employees, it is advisable for employers to corroborate the results by way of other evidence, such as the results of more accurate tests, prior to taking adverse employment decisions, including disciplinary action.

This case also illustrates the difficulty that employers may face in enforcing a ‘zero tolerance’ policy in circumstances where an employee has only a small amount of alcohol in the system. This is something employers ought to bear in mind when drafting their policies.