Extracted from:

Pandemic Planning Policy for Employers: Responding to the Coronavirus (COVID-19)

It is not likely reasonable to require confirmation that an employee tested negative for COVID-19 before returning them to the workplace whether from illness, leave, or travel. Testing for COVID-19 is limited and currently restricted to cases meeting certain criteria. It is not widely accessible by family physicians or employees seeking to return to work.

Generally, it is advisable to self-isolate for the 14-day incubation period, as recognized by PHAC,[7] after suspected exposure to COVID-19. If an employee is not experiencing symptoms after 14 days of self-isolation, it may be reasonable, depending on the circumstances, to return the employee to the workplace without a medical certificate. If an employee has been experiencing symptoms, they should remain out of the workplace for the period advised by their treating physician or other healthcare professional.