Driving under the influence of cannabis


Ontario’s legalization of cannabis will debut government-controlled, online cannabis sales October 17, 2018, with private retail sales set to hit stores on April 1, 2019. The legalization of cannabis brings with it a unique set of ambiguities and problems to the driver who potentially will test positive for Tetrahydrocannabinol (THC), the main psychoactive compound found in cannabis. With the legalization of cannabis and new regulations in place, we here at Toronto DUI Lawyers want to address the question, is there an inherent risk of criminalizing people who are not actually impaired?

As spelled out in the Criminal Code, drivers with a blood concentration of five nanograms of THC per one milliliter of blood are considered impaired, plus an offense at concentrations of three nanograms of THC per one milliliter of blood in combination with 20 milligrams per 100 milliliters of alcohol.

In addition to this, the criminal law response to drug-impaired driving was strengthened  by authorizing police to use additional tools, including approved drug-screening equipment. Law enforcement officers are equipped with new technology to administer roadside tests for drugs and alcohol, along with the collection of blood samples.

In order to administer these field tests, law enforcement must suspect you are impaired.  Drivers with blood concentrations of THC greater than two nanograms, but less than five nanograms, would face a summary conviction rather than a criminal one. Blood concentrations greater than five grams will result in a criminal conviction with hybrid offenses if alcohol is also detected.

The issue arises in that roadside test, especially in cold climates where technology may be susceptible to harsh weather conditions, readings are not always accurate. In addition to this, THC levels in the blood decrease rapidly, and detection levels may differ when the blood test is administered within two hours of the traffic stop.

These ambiguities and potential pitfalls translate to a sort of  “no tolerance” approach to cannabis use and driving. Long-term cannabis users, such as the medically prescribed, have developed a tolerance, and may not behave impaired. In addition to this, cannabis affects every user differently.

The guideline of five nanograms of THC per one milliliter of blood being considered the point of impairment was suggested by English scientists. However, cannabis use is strictly prohibited in England, and their findings are based off studies based on small populations with findings that are difficult to generalize.

Another thing to consider is what is actually considered “driving.” Many judges look at whether or not the vehicle was turned on or off, moving or stationary, operable, keys were in the ignition and more.

The legalization of cannabis brings its own unique set of considerations to DUI laws, and drivers who use, whether medically or recreational, need to be well-versed in the potential risks of getting behind the wheel. When faced with a potential DUI conviction, it is important to seek out professional legal representation who will explore every available defense and help you avoid conviction.