Silence from the Government
Nearly nothing has come from the goverment in the form of guidance on marijuana in the workplace. With a likely July 2018 legalization date, workplaces are trying to prepare in advance.
Enform's tweet below sums it up best:
In addition, consideration will need to be given to the use of marijuana in workplaces. For example, a zero tolerance policy could be applied for those who operate heavy machinery or conveyances.
Without guidance, Canadian employers are in a tough situation especially when it comes to prescribed medical marijuana. People have a right to access medical marijuana and use it, but that may be in direct conflict with existing workplace safety policies.
There is still no test for active impairment and the only tests easily available are for recent use, which doesn't prove impairment. Human rights legislation dictates that employers cannot discriminate against an employee or applicant who has a disability; however, if your employees cannot perform their jobs safely given the medication they are using, there is still a duty to accommodate up to undue hardship. Your company may be required to move the employee to a position that is not safety-sensitive, or, if that is not possible, place the employee on leave until they can safely return to work.
If modified work is appropriate, employers should reserve the right to confirm the nature and duration of the work restrictions with the employee's physician. We also recommend obtaining a legal opinion on all of the above.