Employers should take a proactive approach in dealing with this changing landscape and, to this end, we have outlined some key action items below.
• Marijuana is currently illegal and listed as a controlled substance under the Controlled Drugs and Substances Act.
• Medically authorized marijuana is regulated under the Access to Cannabis for Medical Purposes Regulations (legal access to permitted marijuana was first provided in 1999 under an earlier set of regulations).
•Canadians with medical authorization provided by a physician can access marijuana for medical purposes.
• Medical marijuana is not approved by Health Canada as a therapeutic substance and Health Canada has not expressed any conclusions as to the appropriate use of medical marijuana (or other cannabinoids) for medical purposes.
• In April 2017, the Canadian government introduced Bill C-45 (the Cannabis Act) to parliament. The legislation aims to create a framework for the production, distribution, sale and possession of marijuana by the Summer of 2018.
• The use of medically authorized marijuana has been rising steadily in Canada since its legalization, with many physicians and researchers voicing their support for its use in connection with the alleviation of symptoms where other therapeutic options have failed or been exhausted. 
• Recreational marijuana use is also expected to rise once legalization comes into effect.
• Marijuana use can trigger an employer’s duty to accommodate under human rights legislation, both in respect of individuals medically authorized to use medical marijuana and those suffering from marijuana addictions.
• Legalization of recreational marijuana creates an issue as to whether, how and to what extent marijuana possession and use can be tolerated in the workplace or at work-related events.
• Both of the issues above must be dealt with in a manner that takes into account an employer’s overarching obligation to ensure the health and safety of its workers.
Drug Policies and Training:
• The use of workplace policies is crucial to setting in stone what is and is not acceptable concerning marijuana use and possession in the workplace and at workplace social events.
• Policies must be reasonable and should take into account the nature and circumstances of the employer’s business.
• Policies can put in place a process for disclosure of marijuana use for medical purposes, describe the accommodation process and confirm the paramountcy of a healthy and safe workplace.
• Employers can also manage safety risks in the workplace by implementing a drug policy that encourages employees to proactively disclose drug addictions (for further discussion of this topic, see our blog post on the Stewart v Elk Valley Coal Corp. decision).
• Policies can be used to stipulate that recreational use and impairment while on duty will not be tolerated and outline a process to be followed in instances of suspected recreational use or impairment. In addition, sale and distribution of marijuana in the workplace can be prohibited by policy.
• If desired, employers can use workplace policies to address the use of recreational marijuana, similar to the approach taken to alcohol consumption, in relation to workplace social functions.
• Training on workplace drug policies should accompany their implementation to ensure employee awareness and understanding. New employees should also be provided with such training and supervisors and managers should be educated on their particular roles and responsibilities.
• All employees should be required to sign and acknowledge their understanding of the drug policy.
•We suggest that employers review their existing drug policies (or put one in place), in the coming months and before July 1, 2018. Employers are well advised to consult with legal counsel as they work to craft and implement such policies.
Responding to Suspected Marijuana Use:
• Meet with the employee in confidence, review observations or signs of use, provide an opportunity for response and assess the situation. In some situations, it may be appropriate to refer an employee to a third party for further assessment.
•The duty to accommodate may be triggered if the employee advises that he or she is medically authorized to use marijuana, has a marijuana addiction, or shows signs of addiction.
• Drug testing in Canada is appropriate in limited circumstances only, and very generally, where appropriate, may be used to measure present impairment. As there is currently no drug testing method that detects present impairment as a result of marijuana use, employers are advised to focus on the steps outlined above when responding to suspected use of the drug.
• Discipline and in some cases termination of employment may be appropriate but employers should proceed cautiously and evaluate the appropriate action on a case by case basis.
• Given the sensitivity and legal risks associated with confronting an employee as to suspected drug use, and in light of the changing landscape on this issue, we suggest that employers consult with legal counsel where possible when contemplating discipline or termination.
Accommodation Process (Medically Authorized Marijuana):
• Proceed on a good faith basis, recognizing that medically authorized marijuana should be treated in the same manner as any other prescription medication:
• As part of the procedural duty to accommodate, obtain the employee’s medical authorization to use marijuana, engage in dialogue with the employee in order to understand his or her limitations (including any risk of impairment) and canvass options for accommodation.
• On the substantive level, an employer’s response to a request for accommodation will vary based on the particular needs of the employee and the type of work he or she performs, and must be weighed against health and safety risks to determine whether putting an accommodation in place will create undue hardship for the employer.
• For an employee in a safety sensitive position, health and safety considerations may require an employer to modify the employee’s role such that they are no longer performing safety sensitive duties or to put the employee on a leave of absence, unless such accommodations cause undue hardship for the employer.
• A similar process as above should be followed in the case of marijuana addiction, except in this situation an employer may need to be more proactive as an employee may not be forthcoming as to their needs or may not recognize that they have an addiction.
• Respect the employee’s privacy, maintain confidentiality, and document all aspects of the accommodation process.
 The College of Physicians and Surgeons of Ontario, Marijuana for Medical Purposes (Policy 8-16)