Stopping cannabis use in its tracks

With the decriminalisation of the private use of cannabis, it has become more challenging to prevent, monitor or take legal action against marijuana use among truck drivers. MARISKA MORRIS investigates

It is no longer a criminal offence for individuals to consume cannabis in the privacy of their own homes. While some might rejoice, this brings with it a host of challenges for transport operators who are attempting to curb or prevent marijuana use among drivers. Even with a zero-tolerance policy, traditional approaches to testing for cannabis are insufficient.

Why bother at all? Well, as Alco-Safe MD Rhys Evans points out: “There are numerous dangers to driving while under the influence of cannabis, such as slower reaction times, inability to concentrate for long periods, poor decision-making and a higher risk of falling asleep at the wheel on longer journeys.”

It is in the best interests of the driver and company to ensure that no cannabis is consumed before the driver operates a vehicle. While there are some other tell-tale signs (such as smell or behaviour) that can indicate intoxication, drug testing is still the most reliable way to determine whether a driver is under the influence.

However, traditional urine testing is no longer enough. Greg Kew, occupational medicine specialist, notes: “After the Constitutional Court ruling, urine testing is now no longer enough, as it can identify only the use of cannabis, which is no longer a criminal offence.

“The results of a urine test can’t be used as a sanction for being under the influence without additional evidence that indicates the person was acting in a similar way to someone who is under the influence.” Traces of marijuana, or inactive cannabolites, can be found in the body for weeks after use.

These inactive traces of the substance have no psychoactive impacts on the individual. It simply indicates that the individual has used the substance. Rather than testing to see if the driver uses cannabis (traditionally done through urine tests), transport operators need to test whether the driver is under the influence of cannabis.

This is where drug-a-lysers, or saliva drug tests, can assist. By testing the presence of the drug in the saliva, companies are better able to determine if the individual’s capabilities are impaired.

“The benefits of saliva drug tests are fewer privacy issues, simpler steps for testing and a smaller chance of the test subject adulterating the sample,” Evans says. “The most relevant benefit is that saliva tests have a very short window of detection after cannabis is used – on average between two and six hours.

“This is useful in showing very recent use in comparison to a urine test, which can detect cannabis use for days and even weeks after a person has stopped smoking.”

For transport operators who are not planning on implementing a zero-tolerance policy, it is important to determine the acceptable levels of tetrahydrocannabinol (THC) – the psychoactive factor in cannabis. There is no real guideline in South Africa to determine an acceptable level.

Kew recommends that the cut-off point for oral fluid cannabis screening be set at around four nanograms per millilitre and two nanograms per millilitre for the confirmatory test. Two nanograms per millilitre is said to be the equivalent of 0,5 g/l blood alcohol concentration. When the acceptable THC levels are determined, it must be clearly mentioned in the company’s drug policy.

A comprehensive and clear substance-abuse policy is crucial to prevent the abuse of cannabis at the workplace. Evans explains: “The policy should state the legal acts, such as the Occupation Health and Safety Act with regard to intoxication from alcohol and other drugs. The company’s stance on the use of cannabis should be mentioned and the reasons behind this.

“It must be clear what health and safety procedures will be implemented in order to control the use of cannabis and the consequences for a driver who has a positive test.”

In addition to clearly communicating the company’s policy to the driver, Evans also recommends training: “It is useful to provide employees with education on the dangerous effects of cannabis on the brain and lungs, as well as the heightened risk of having an accident.”

With the correct training, a comprehensive company policy and drug-testing devices, transport operators can ensure the safety of their drivers, vehicles and other road users.