Pre-employment Drug Testing in Canada: An Employer’s Guide

  • Employer advice
drug and alcohol test vials
Charlie Herrera Vacaflor

Charlie Herrera Vacaflor, Employment Law & HR Content Senior Consultant

(Last updated )

Conducting pre-employment drug tests in Canada can be a valuable tool for employers when they wish to ensure the suitability of potential employees in safety-sensitive positions. These are usually roles that require employees to operate heavy machinery, administer healthcare, or carry out transportation-related duties. 

However, before conducting pre-employment drug tests, employers must ensure they have valid job-related reasons to do so. Additionally, they must ensure that all drug testing follows fair and non-discriminatory employment practices, with respect to individual rights and privacy. Especially when it may concern an employee’s substance dependency and addiction.

Laws to consider before conducting a pre-employment drug test 

In Canada, drug testing in the workplace is regulated by a combination of federal and provincial laws, labour codes, and human rights legislation. These regulations aim to strike a balance between respecting individuals’ rights and privacy while also maintaining safety for both employees and the public.

Here are the laws employers must consider before conducting pre-employment drug tests: 

Human rights law and pre-employment testing

Pre-employment drug testing could be considered discriminatory across Canadian human rights law. This is because drug and alcohol testing could reveal a person’s substance dependency and addiction and poses a risk of discrimination against the candidate if a job offer is rescinded. Unless an employer can prove that there is a bona fide occupational requirement (BFOR) for testing, it is best practice for employers not to conduct pre-employment drug testing for non-safety positions.

If an employer is recruiting for a safety-sensitive position, then pre-employment drug testing could be justifiable as policy for the promotion of workplace safety. Employers should still justify drug testing as a BFOR. Withdrawing a job offer because of a positive test result without first considering the duty to accommodate could lead to discrimination against the candidate. If the candidate requests accommodation, employers have an obligation to provide them up to the point of undue hardship.

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Occupational health and safety regulations (OHS)

Provincial OHS regulations require employers to provide a safe working environment for workers and prevent workplace hazards. It may be necessary for employers to implement health and safety training that addresses drug impairment or have a drug and alcohol policy in the workplace.

Privacy laws

Employers must respect employees' privacy rights when collecting, storing, and using their personal information, including drug and alcohol testing results. This includes following the guidelines set by the Protection and Electronic Documents Act (PIPEDA) as well as being compliant with provincial information protection legislation.

Safety-sensitive positions

Some occupations and industries may conduct pre-employment or impairment-related drug and alcohol testing for safety-sensitive positions. These include:

  • Transportation and logistics: Roles such as truck drivers, airline pilots, ship captains, and other positions that involve the operation of vehicles or transports. 
  • Aviation: Besides pilots, employees working in aviation maintenance and air traffic control may be subjected to drug testing.
  • Healthcare: Jobs in healthcare, such as doctors, nurses, and paramedics may require drug testing, especially when patient safety is a concern.
  • Law enforcement: Police officers, correctional officers, and other law enforcement personnel often undergo drug testing due to the nature of their work.
  • Emergency services: Firefighters and emergency medical personnel are often subject to drug testing.
  • Construction and mining: Workers in these industries often operate heavy machinery and equipment, making sobriety crucial for safety.
  • Oil and gas industry: Employees working on oil rigs or in related fields may face hazardous conditions and may be subject to drug testing.
  • Manufacturing: Positions in manufacturing may require drug testing if they involve operating machinery or working with dangerous equipment.

Conducting pre-employment drug testing

When conducting pre-employment drug tests, employers must keep several factors in mind to ensure the process is aligned with legal requirements:

Necessity and relevance to the job

Pre-employment drug testing should only be considered when it is necessary for the effective performance of a safety-sensitive position. It's crucial to assess whether drug or alcohol use could impact an employee's ability to carry out essential job functions and if impairment could lead to accidents and hazards.

Informed consent

Employers must obtain informed consent from candidates before conducting drug and alcohol tests. Consent should be obtained in writing and should clearly state the purpose of the test, the types of drugs being tested for, and the consequences of a positive result.

Testing procedures

Pre-employment drug testing must follow recognized testing standards, including chain-of-custody procedures for samples. It's important to use accredited and certified labs and medical professionals for sample collection and analysis.

Most common drug tests for employment

Urinalysis: Urine samples can be used to detect a wide range of drugs, including marijuana, cocaine, amphetamines, opiates, and more. This is the most commonly used method for pre-employment drug testing.

Saliva tests: These tests are also common because they are non-invasive, easy to administer, and can detect recent drug use. They are suitable for reasonable suspicion or post-incident testing.

Hair tests: Hair tests can detect drug use over a longer period, often up to 90 days. They are useful for positions where long-term drug history is relevant.

Blood tests: Blood tests are highly accurate and can detect recent drug use. However, they are uncommon in employment testing due to their invasiveness.

Breathalyzer tests: These tests can detect the presence and concentration of alcohol in the breath. However, they can’t uncover other illicit drug use, only alcohol impairment.

Pre-employment drug testing after marijuana legalization in Canada

Canada legalized the recreational use of marijuana in 2018, which may affect employers’ existing drug testing policies. Testing for marijuana use is still allowed in certain safety-sensitive positions, but employers should be aware that testing positive for marijuana doesn't necessarily indicate impairment at the time of the test due to its long-lasting metabolites.

Here are a few things to consider when implementing pre-employment drug testing after marijuana legalization:

Impairment VS use

Testing for the presence of marijuana in an individual's system does not necessarily indicate impairment. Unlike alcohol, which has standardized tests that can immediately detect impairment, measuring THC levels (tetrahydrocannabinol), the psychoactive compound in marijuana, typically takes at least 24 hours. This time gap makes it more challenging to establish if the person is actually impaired.  

Clear workplace policies

Under Occupational Health and Safety legislation across Canada, employers are required to have prevention programs in place to protect employees from workplace hazards (e.g., administrative hazard controls, engineering controls, substitution controls).

Since substance use may lead to impairment and accidents, employers can benefit from having a clear and well-communicated drug and alcohol policy. Ideally, these policies would address substance use in the workplace, establish practices that prioritize employee health and safety, and detail the consequences and disciplinary action for violating them. 

Duty to accommodate

Employers have a duty to accommodate employees who have disclosed legitimate medical reasons for using marijuana. Similarly, employers must accommodate employees with substance dependency, which is considered a disability under human rights laws. In both cases, employers’ duty to accommodate is not absolute; employers do not have to agree to accommodation requests that put their organization in undue hardship.

Employers should always discuss with the employee if they require special accommodations or alternative work arrangements if they are in a safety-sensitive position.

Cannabis Act

The Cannabis Act now includes amendments to the Non-Smokers’ Health Act (NSHA) that prohibit the smoking and vaping of cannabis in workplaces. The amendments aim to protect non-smokers from second-hand smoke in federally regulated workplaces and on certain modes of transportation.

Pre-employment drug testing in Canada


In Ontario, employers must navigate pre-employment drug testing within the framework of human rights legislation, primarily the Ontario Human Rights Code. The Code prohibits discrimination based on several grounds, including disability. Drug addiction is considered a disability under this law. 

While pre-employment drug testing in Ontario is generally legal, it must be conducted with a focus on job relevance and safety. Random testing and blanket drug testing may face challenges under human rights legislation.

British Columbia

In BC, pre-employment drug testing is also subject to the BC Human Rights Code. Employers must ensure that testing is non-discriminatory and based on genuine occupational requirements. 

Drug testing can only be enforced on an employee in circumstances where there is reasonable suspicion of impairment, such as after a significant incident or a “near-miss” mishap. Random drug testing is generally not allowed unless it is used to identify and remove an impaired employee from a safety-sensitive environment. 


Under Alberta’s Occupational Health and Safety (OHS) Act, employers, supervisors, workers and other worksite parties have an obligation to address impairment when it creates a hazard or unsafe work conditions. 

Currently, the legislation doesn’t address testing for impairment. However, provincial case law has ruled out pre-employment drug testing as being prima facie discriminatory. Tribunals from Alberta have decided that pre-employment drug testing is intended to screen out any drug use with the purpose of promoting workplace safety. It is best practice for employers to administer drug testing for safety-sensitive positions, job-related reasons, and are required to protect individual rights and privacy.

Employee assistance programs (EAPs)

Consider implementing Employee Assistance Programs that provide support for employees dealing with substance abuse issues. EAPs provide free short-term counselling for personal or work-related problems, including addiction. These programs can help employees and their immediate families seek treatment and support while maintaining confidentiality. When employers invest in their staff’s mental and physical well-being, they also benefit from improved employee productivity, engagement, and morale. 

Do you need help creating a pre-employment drug testing policy?

Our HR experts can develop drug and alcohol policies, workplace procedures, and health and safety practices to help your business succeed. See why more than 6500+ employers across Canada trust Peninsula as their external HR partner. Call today at 1(833) 247-3652 to find out more.

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