Can my employer ask me to take a lie detector test?

QUESTION: Recently a significant amount of cash went missing from the retail store where I work. Corporate head office has sent in investigators and they are asking us if we would “voluntarily” be willing to take a lie detector test. I am innocent but the thought of taking some sort of lie detector test gives me the creeps. Do I have to?
ANSWER: The Employment Standards Act of Ontario prohibits anyone governed by that legislation from requiring, requesting, enabling or influencing, directly or indirectly, an employee to take a lie detector test. By asking you to voluntarily take the test the employer has violated the Employment Standards Act.       
If you refuse and suffer any negative consequences, like a termination or a reduction in your scheduled shifts, you can complain to the Ministry of Labour and the Employment Standards Act officer can order the employer to compensate you for any losses, including the loss of your job or shifts. They can order the employer to rehire you and, in some cases, fine the employer.
The machine used to “detect” lies actually does no such thing. It actually records physiological responses you have to questions put to you over which you have no conscious control such as your heart rate, blood pressure, respiration and skin conductivity. 
If you were actually to take a polygraph test, the person administering it would likely start by telling you how very accurate the test is so that you become concerned about being deceptive when you are asked the questions.
Before you are asked if you stole the money missing from the store, you could likely be asked questions like, “Have you ever betrayed anyone who trusted you?” or “ Have you ever lied to get out of trouble?”  If you show more stress or the same stress when you are answering those questions compared to when you are  asked whether you stole the money, you are assumed to be telling the truth about not being a thief. A truth-teller is assumed to fear that control question more or the same as the relevant question because it’s asking about past truthfulness and is open-ended and vague. Who knows what “betrayed” means to someone else? Who has never lied to get out of trouble? ( I know. I should speak for myself.)
When the government first introduced this provision to the Employment Standards Act in 1983 it indicated that the use of lie detectors in the workplace was unacceptable and that they were an unwarranted invasion of privacy. It felt that they were of questionable accuracy and reliability and that they engender a sense of fear in the workplace that is destructive to the employer/employee relationship. If anything, over the  last 31 years, the reliability of lie detector tests has come under even more scrutiny. The problem is that there is limited evidence that any pattern of reactions is unique to deception. Some people can be nervous even though they are telling the truth and some people can be calm when lying.
While the people that administer these tests believe that they are 90% accurate, some critics have said that they are, at best, 65% accurate. That’s only 15% better than flipping a coin. It may be that the employer is asking you to voluntarily take the test, despite the law, in hope of provoking somebody to confess. In the absence of anyone doing that, however, lie detector tests give lots of false positives and your employer is pretty much wasting its time and money as well as breaking the law.
Finally, it’s easy for me to tell you that you can decline the test and to tell you about all the powers the Ministry of Labour investigating officer has. That officer, to be fair, will not be there the next time you need an unscheduled day off or any kind of consideration or favour from your employer. The hard reality is, only you can make this decision.
Ed Canning practices labour and employment law with Ross & McBride LLP, in Hamilton, representing both employers and employees. You can email him at For more employment law info visit:
Ed Canning
Ed Canning
P: 905.572.5809