Drug and alcohol testing is increasingly being implemented in workplaces across Canada. The law has not yet caught up with these developments.  There are no specific laws prohibiting or requiring these types of tests, and courts and labour arbitrators are left to establish rules on a case by case basis. (1)

Those in favour of testing argue that mandatory drug and alcohol testing promotes safety and security in the workplace. Opponents say that mandatory testing violates privacy rights without reasonable grounds and can lead to discrimination on the basis of an actual or perceived disability (an addiction is a disability under human rights law). Blood and urine can reveal what medications a person is taking (which can indicate medical conditions), the existence of a pregnancy; genetic defects or predispositions or other, undiagnosed medical conditions. So there must be strict controls on which tests are ordered. Further, unless the environment in which collection takes place is strictly controlled, the act of collection can itself violate privacy. (2)

The reliability of urinalysis (the main method of drug testing) can be questionable if the person tested has recently consumed legal products such as poppy seeds, herbal teas or over the counter medication, or if the sample is tainted with salt, vinegar, or other chemicals. Finally, urinalysis cannot detect current or past impairment or the quantity of the drug consumed. It can only indicate whether a drug was consumed within the recent past (for example, up to one month for marijuana).

Mandatory Drug Testing – A Legal Grey Area

Currently, there is no specific law requiring or prohibiting mandatory drug testing in Canadian workplaces. Employers in the public and private sector are instituting policies on a piecemeal basis across Canada, often as a result of being a subsidiary of a U.S. parent corporation, because mandatory testing in many industries is required by law in the U.S. For example, U.S. motor carrier safety regulations require trucking companies to have workplace drug and alcohol policies that include pre-employment testing, post-accident testing, reasonable suspicion testing, return-to-duty testing, follow-up testing and random testing. Canadian carriers that operate in the U.S. are required by U.S. law to comply with these regulations. In other industries, U.S. parents simply seek to impose their more stringent policies on all their employees, even those employed by Canadian subsidiaries.

As a result, some of the leading court cases on drug testing issues result from challenges by unionized employees in Canadian subsidiaries of large U.S. multinational corporations. Although there is no doubt that drug and alcohol testing in the workplace is very privacy-invasive, these court challenges have not usually involved privacy law, but rather have been decided under human rights law on the grounds that they discriminate on the basis of real or perceived disability.

In some of these cases the drug and alcohol testing policies that permit the employer to automatically dismiss or not to hire an employee on the basis of a positive test have been found to be discriminatory unless they are related to an actual, legitimate job requirement (“bona fide occupational requirement”) and the employer provides reasonable accommodation of a disability. (3)

Labour arbitrators have been very clear that drug testing requires either a reasonable cause or a workplace accident or “near-miss”, and a rehabilitation plan for the employee. Labour arbitrators have not accepted unionized employers’ claims that random drug testing is necessary for deterrence or safety, unless the collective agreement deals with it directly. (4)

Judges have been more open to allowing random drug testing. In particular, courts in Alberta have been less protective of individual privacy rights. So for example, in Alberta, the court allowed pre-employment drug tests in an highly hazardous workplace where the purpose of the policy is to prevent workplace accidents by reducing workplace impairment, because the policy identifies individuals who may engage in recreational use of marijuana, and evidence showed impairment is possible days after use, thus posing a safety risk in the workplace. In the particular case, the court found that the employee was fairly terminated when the test revealed that he had smoked marijuana before he was hired, because the workplace was already dangerous and the lingering effects of marijuana raised concerns about his ability to function in a safety-challenged environment. (5)

Some courts and arbitrators have concluded that a policy of random testing is not legitimate, while others have said that a policy for random testing may be legitimate in safety-sensitive positions but only if the test can establish current impairment. Thus a random breathalyser test is acceptable; random urinalysis, or a buccal swab (a swab of the inside of the mouth) which must be sent to a lab and cannot indicate current impairment, is not acceptable. All policies must provide for reasonable accommodation of employees with disabilities (including addiction and dependency).

A General Rule: Drug Testing Is Permissible Only In Limited Circumstances

So it can be said that generally, employers in Canada cannot use mandatory drug testing for all employees. However, some alcohol and drug testing, in limited and specific circumstances, is permitted by law.  As in all cases involving privacy rights, the privacy rights of the employee must be balanced against the needs of the employer to collect, use and disclose the personal information.

Drug and alcohol testing may be imposed on an employee in circumstances where there is reasonable cause, a reasonable suspicion of impairment or a significant incident or “near- miss” (of an accident). Regular drug testing may be imposed on all employees in a safety-sensitive environment, but is generally dealt with in a collective agreement. Random drug testing of the entire workforce is generally not permissible, but random breathalyser tests are permitted in safety-sensitive workplaces because it immediately identifies current impairment, enabling removal of the employee from a safety-sensitive environment. In workplaces that are not safety-sensitive, the employer must establish that there is an existing problem in the workplace and that other, less privacy-invasive means to address the problem have been ineffective. In British Columbia and Alberta, in workplaces that are more safety-sensitive, the employer is permitted to institute a drug testing policy – including, in Alberta, pre-employment testing – without having to prove that a drug problem exists in the workplace.

In all cases, any employee with a dependency or addiction must be provided reasonable accommodation on the basis of disability. Employers may institute random drug testing of particular individuals if in the particular circumstances there is reasonable cause to do so and it is accompanied by a process for reasonable accommodation.

If You Are Asked to Take a Drug Test

If you are asked to take a drug or alcohol test and you believe that your employer’s policy is unjustified, you can do a few different things: seek out assistance from your union if you have one, make a formal complaint with the relevant privacy commissioner


Alberta (Human Rights and Citizenship Commission) v. Kellogg Brown & Root (Canada) Company, 2007 ABCA 426 (CanLII), appeal to the SCC dismissed 2008 CanLII 32723 (S.C.C.)