Cannabis Impairment Far Different From Alcohol Impairment

Cannabis Impairment Far Different From Alcohol Impairment

WIS has highlighted key points in this article.
(June 18, 2018)
The amendments to the Criminal Code through Bill C-46 are far reaching and significant. Originally, the intention was to pass this law in concert with the Cannabis Act to create new driving offences at the same time that marijuana was legalized. However, it appears that this bill is unlikely to come into force until well after the Cannabis Act is passed.
Much of the focus in Bill C-46 is on the criminalization of per se set limits of marijuana, specifically THC, in the blood.
These limits operate to discourage the risk-taking behaviour of having a blood drug concentration that is likely to cause impairment. For example, with alcohol we set the level at 80 mg of alcohol per 100 ml of blood which recognizes that the vast majority of people are impaired at this level. Per se limits cause two main concerns. The first is that it may give the sense that a person is not impaired under that limit. The second is that some individuals may be over the limit but pose no risk deserving of criminal sanction.
Bill C-46 sets limits for a number of drugs, some at zero, but the main focus is on THC. These amendments set three separate levels. The first is at 5 nanograms (ng) of THC per 100 ml of blood. This will be punished similar to the current alcohol over-80 charge. Secondly, there is an offence where a mixture of alcohol above 50 mg with THC above 2.5 ng is also treated similarly to an alcohol over-80 charge.

The third offence is for individuals who are over 2 ng of THC but below 5 ng. This is treated as a lesser offence. It does not carry a mandatory driver’s licence prohibition in the way that other charges relating to impairment or being over each limit do. However, this is still a criminal offence and carries with it the significant impact of a criminal record and is likely to be interpreted at the American border similarly to a possession of drug charges, which leads to inadmissibility to the United States. Even though it is a lesser charge, the consequences are still wide ranging.
Unlike alcohol, there is no consensus among the scientific community regarding what is a safe legal limit for THC.

One of the problems with this drug is that it affects individuals in different manners at different times after ingestion more significantly than at a particular concentration. To put it simply, an individual consuming alcohol is more impaired the higher the level in his blood. The same does not hold true for individuals consuming THC.

Because THC is absorbed into the fat of the body rather than the water and because of the way that it crosses the blood-brain barrier in a different manner than alcohol, its impact is not as linear as alcohol’s.
Members of the general public are unlikely to appreciate their blood drug level due to a lack of experience with this drug and that symptoms may not be apparent at any particular level. Due to the non-linear elimination rate, it will be almost impossible to know what level a person is at without a chemical test being performed.

Unlike alcohol where calculations and charts can give some information, THC is not as simple.
Individuals who consume cannabis will be taking a risk every time they drive even if not impaired. THC can remain in the body for weeks. This should be most worrisome for individuals affected by zero tolerance policies in provinces like Ontario where individuals under the age of 22 must have a zero-blood drug concentration in order to drive legally.

Young people will need to be especially vigilant in avoiding cannabis products if they wish to keep their driver’s licences.

Finally, a thought-provoking issue arises with regard to mens rea issues. It is unlikely that a person will not realize they are consuming alcohol as it tends to have a distinctive taste, but there are a number of THC-laden products, specifically edibles, where the presence of the drug may be unapparent. The individual smoking marijuana knows they are consuming but a person eating a cookie, a chocolate bar or gummy bears at a party may not realize they have consumed THC.

Since this drug can affect inhibitions, a person may operate a motor vehicle without appreciating the danger they pose. Courts will have to carefully scrutinize evidence in these cases in order to protect the innocent while still punishing those with a guilty intent.

While Bill C-46 changes impaired driving laws in very significant ways and eliminates many currently existing defences with relation to alcohol impaired driving, it is likely to create a significant amount of business for criminal lawyers prosecuting or defending drug impaired driving charges.