In short:
The detection limit of devices used by NSW Police in roadside drug testing has come to light amid debate on reforms for drivers using medicinal cannabis.
The roads minister told a parliamentary committee that police had said the devices were set at 50 nanograms per millilitre.
What’s next?
The police minister is due at the committee this Friday where it is expected she will be asked about the drug driving reforms.
The number has long been guarded closely by New South Wales police — the concentration of cannabis in a driver’s saliva that produces a positive drug test.
“They [police] don’t necessarily advertise what the level is,” roads minister Jenny Aitchison told a parliamentary committee on Friday.
Despite the force’s efforts to keep the limits of roadside drug testing under wraps, longstanding detection thresholds have come to light as a proposed legal limit for medicinal cannabis patients is scrutinised.
Section 111 of the Road Transport Act spells out the state’s “zero tolerance” for drug driving.
The concentration of cannabis in a driver’s saliva that will return a positive result has not been disclosed by NSW Police. (Supplied: NSW Police)
Driving with the “presence” of an illicit drug, such as delta-9-tetrahydrocannabinol (THC), in your system is an offence.
But while what the law says is one thing, what happens in practice is another.
Confusion over limit
The device used for the roadside test is called the DrugWipe 3S, made by the German company Securetec.
Its website lists other models, the 5S and 6S, boasting a detection limit of 5 nanograms per millilitre for THC.
Despite multiple ABC inquiries, police have refused to divulge the detection limit of the 3S model used in NSW.
But as Ms Aitchison faced the budget estimates hearing, she was up-front about the figure she said police gave her.
“The DrugWipe is set at 50 [nanograms per millilitre],” the minister said.
Ms Aitchison told a budget estimates hearing the DrugWipe is set at 50 nanograms per millilitre. (ABC News: Romy Stephens)
An incredulous Greens MLC Cate Faehmann pressed her on whether the detection threshold was really that high, and suggested the tests used by police were in fact more sensitive.
The Australian and New Zealand standards for saliva drug tests prescribe a 15 ng/ml cut-off concentration for cannabinoids.
Across the ditch, the government openly states its screening threshold for THC is 15 ng/ml.
New Zealand Police also use the 3S model, but the agency says on its website that its version is made specifically for the country and is not used in other jurisdictions.
“Did somebody mishear someone and put 50 in?,” Ms Faehrmann said.
“I’m trying to understand because medicinal cannabis patients are contacting me. They’re very confused.”
Ms Faehrmann told budget she had been contacted by confused medicinal cannabis patients. (AAP: Bianca De Marchi)
Ms Aitchison was emphatic in her answers.
“What we’ve had in conversations with police is that 50 nanograms was the level set for roadside detection,” she said.
“It’s the same kind of test that’s been used for two decades.
“But who and what set those detection levels, I can’t tell you.”
Legal limit for medicinal cannabis patients
For the first time, the 50 ng/ml limit is set to be written into legislation.
A Labor bill has passed the lower house and is working its way through the Legislative Council.
The reform would give registered cannabis patients two warnings every two years if they were caught exceeding the limit while driving.
On the third strike, drivers would face the full force of the law, including a minimum three-month licence suspension.
Registered cannabis users who return a positive result will receive a warning for a first or second detection within two years. (Supplied: NSW Police)
Technically, someone with a cannabis prescription would not commit an offence at all if they had fewer than 50 ng/ml in their system.
But given the calibration of the DrugWipe stated by the minister, it seems unlikely they would test positive in the first place.
Limits that apply to all drivers
One of the most revealing moments during Friday’s hearing was when Transport for NSW deputy secretary Sally Webb detailed the current process for enforcing drug driving laws.
Ms Webb likened the DrugWipe device to a COVID-19 test in that it returns either a positive or negative result.
Upon a positive reading, she said, the driver repeats the DrugWipe test with a device from a different batch.
Upon a second positive result, the driver is suspended for 24 hours — an automatic ban that would also apply to registered cannabis patients.
According to Ms Webb, police then take a saliva sample which is put in an esky and transported to a laboratory.
Drivers will be suspended for 24 hours if they return a second positive result. (Supplied: NSW Police)
It is the laboratory result, she said, that is used to determine whether a driver is prosecuted.
“The threshold then for laying charges is 10 ng/ml,” Ms Webb said.
The threshold for charging medicinal cannabis patients who have run out of warnings would be 50 ng/ml.
Questioned about the sensitivity of the roadside test, the senior official said the DrugWipe was “guaranteed” to return a positive result at 50 ng/ml but could also pick up lower levels.
“It will at least detect 50, but it could detect 45, 40,” Ms Webb said.
A NSW Police spokesperson said questions about the equipment should be directed to the manufacturer.
“Driving with the presence of an illicit substance is an offence,” they said.
Police Minister Yasmin Catley is set to be questioned about the drug driving reforms when she is due to appear at estimates on Friday.
https://www.abc.net.au/news/2026-08-23/nsw-drug-testing-limits-questioned-as-police-stay-silent/107065740
