Until now, there has been no widely available test to tell if a person is under the influence of dagga. The urine test that is widely used can only indicate whether the person has taken dagga any time within the past month - not whether they are under the influence.
Taking dagga at any time in any form used to be illegal. Now you’re allowed to take dagga in the privacy of your home and law enforcement agencies as well as employers are finding new and more accurate ways of testing - similar to a breathalyser at a roadblock.
The limitations of urine testing have been especially clear at the Commission for Conciliation, Mediation and Arbitration (CCMA), where multiple cases have arisen from employees being fired after testing positive for cannabis - even though they may not have been under the influence at work.
Attorney Craig Harvey has specialised in cannabis cases over the past three years and is awaiting judgment from the CCMA for another client fighting dismissal following a urine test.
“In terms of the law, somebody is entitled to smoke cannabis at home,” said Harvey.
“If you used it yesterday, you come to work, you shouldn’t be under the influence, but you’ll test positive (on a urine test).”
Traces of dagga can remain in your body for weeks after you last smoked or ingested dagga.
“The saliva test shows if you used it in the last three hours. The saliva test is now the most accurate.”
Quinton van Kerken is an expert witness in Harvey’s CCMA case and has run a drug-testing company of his own.
“With cannabis, we’ve got about a three-hour window where it’s effective and you’re actually ‘stoned’. After that there’s nothing. It just happens to be in your system,” Van Kerken said.
“How can something that you do legally in the comfort of your own home suddenly become illegal when you set foot into work?”
He said there were a few different saliva tests entering the market.
One test looks like a lollipop with a sponge head, which you put in your mouth. It absorbs your saliva, which is then dripped into chemicals that it reacts with. Within a minute or two, the test will tell you if the subject has smoked dagga the past three hours.
The Western Cape Department of Transport and Public Works said it would look at getting the saliva tests approved for potential use for testing driver impairment at roadblocks, similar to a breathalyser.