Can a Legal CBD or Hemp Product Get You Charged With Drug Driving?

The Short Answer

Two different products, two different answers.

A hemp seed food bought in an Australian supermarket — hemp seed oil, hulled seeds, hemp flour, a hemp beverage — has to meet a THC limit to be sold at all. Food Standards Australia New Zealand tested that question before those foods were approved, and its own conclusion was that a positive saliva or urine test from eating them is unlikely. The numbers are below.

An oil sold as CBD oil, CBD hemp oil or cannabis oil, extracted from the flowers or leaves rather than pressed from the seed, is not covered by those limits. Its actual THC content is not something you can check from the label. That is the product that gets people charged.

And if a relevant drug is detected, the source of it makes no difference to the charge. Buying a product legally is not a defence to drug driving.

"How Much THC Is Allowed in a Legal Hemp Food?"

The Food Standards Code sets a limit for each type of hemp seed product:

• Hemp seeds — not more than 5 mg/kg of total THC, and for retail sale the seeds must be non-viable and hulled.
• Oil pressed from the seeds — not more than 10 mg/kg.
• A beverage made from the seeds — not more than 0.2 mg/kg.
• Any other product extracted or derived from the seeds, hemp flour included — not more than 5 mg/kg.

"Total THC" there means delta-9-tetrahydrocannabinol plus its acid form. The plant itself has to be low-THC cannabis, meaning the leaves and flowering heads carry no more than 1% THC. The only cannabinoids allowed in the finished product are the ones that were naturally in the seed — nothing can be added.

Those limits are not zero. Queensland's drug driving offence has no threshold in it. That gap is the reason this question gets asked at all.

"So Could a Hemp Food Actually Fail Me?"

On the food regulator's own figures, it is unlikely. Before hemp foods were approved for sale, Food Standards Australia New Zealand worked through the roadside testing question directly. It took a 30 g cookie made entirely of hemp seed at the maximum permitted THC level. The estimated THC level in oral fluid was 0.86 ng/mL. The confirmatory cut-off in the Australian Standard for oral fluid testing is 10 ng/mL — about twelve times higher. That calculation assumed the whole cookie was hemp seed at the maximum limit, which overstates a real product, where hemp is typically no more than a fifth of the ingredients.

Its stated conclusion was that it is unlikely that consumption of hemp foods containing THC at the permitted maximum levels could produce a positive result in oral fluid or urine testing done to the Australian Standards.

Two limits on that. It rests on the product actually complying with the THC limits, which an imported or online product may not. And Queensland's roadside device is approved under a regulation rather than by that Standard, so the figures are a good indication of the risk, not a guarantee about a particular machine on a particular day.

"What About the CBD Oil I Bought Online?"

Different position. The Food Standards Code permits hemp seed and products derived from the seed. An oil extracted from the flowers, leaves or stalks is not within that permission and cannot lawfully be sold as a food in Australia. Neither can a product with cannabinoids added to it, even if the base was seed oil.

A product sold outside those rules is not held to the 5 and 10 mg/kg limits, and nothing on its label has to be accurate about THC content. Overseas sellers are not bound by the Australian limits at all.

There is a labelling test you can apply yourself. A hemp food lawfully sold in Australia cannot be presented as having a psychoactive effect, cannot carry a nutrition or health claim about cannabidiol, cannot show any part of the plant other than the seed, and cannot use the word cannabis or marijuana on the label. A product being marketed on its CBD content and its effects is telling you it is not a compliant hemp food.

"CBD Isn't One of the Drugs They Test For, Is It?"

It is not. The four drugs prescribed for roadside saliva testing in Queensland are MDMA, cocaine, delta-9-THC and methylamphetamine. Cannabidiol is not on that list, and a CBD isolate with no THC in it should not produce a positive result for THC.

The THC that travels with the CBD is the problem, not the CBD.

"Isn't 'I Didn't Know It Had THC in It' a Defence?"

No. The general criminal law defence of honest and reasonable mistake of fact is switched off for this section of the Act by an express provision. Believing a product was THC-free, including because it was legally sold to you, does not answer the charge.

It is still worth raising. What you were taking and why goes to how a magistrate deals with you at sentencing, even though it does not defeat the charge.

"How Long Would It Show Up For?"

There is no reliable figure that applies to everyone. Detection time in saliva depends on how much was consumed, how often, and individual metabolism. There is no published safe waiting period for a trace-THC product the way there is a rough guide for alcohol and body weight. Regular use of a THC-containing product carries more risk than a single serve, and neither can be reduced to a number of hours.

"What Happens to the Saliva Sample?"

It can only be used for the drug test. The Act prohibits using it for DNA analysis to work out whether you might be a suspect for something else. If the test shows no relevant drug, the sample has to be destroyed as soon as possible after the result is known. If it shows a drug, it is destroyed once it is no longer needed for the case, including any appeal.

"What About Prescribed Medicinal Cannabis?"

Related, but a separate situation, covered on our main page — a valid prescription is also not a defence to this charge. The practical difference is the paperwork. A prescription comes with a treating doctor, a dosing schedule and medical records, which give a magistrate something concrete. A CBD oil bought online, with no stated THC content and no medical basis, gives a court much less.

"What Should I Do?"

• Work out which kind of product you have. Seed-derived and sold as a food in Australia, or an extract of the flower or leaf. The second carries the real risk.
• Keep the packaging, batch details and any certificate of analysis. If you are charged, that is the material that shows what you were actually taking.
• Treat any THC-containing product as a risk on a day you have to drive, whatever it cost and however you feel.
• If you are charged after using a product you believed was safe, tell your lawyer. It will not defeat the charge and it can still change the outcome.

How We Help With This

Send us the charge paperwork and tell us what you were using. We will tell you plainly what that context can and cannot do in your case, and what to put in front of the magistrate.