We researched the law on radon and daycares.
The Interior Health Authority has implemented requirements for daycares to test for radon and mitigate if levels are over Canada’s Radon Guideline of 200 Bq/m3. Other health authorities could do this or the Ministry of Health could address radon as a standard or practice.
There are also many general health and safety laws that do not explicitly mention radon but that should cover it:
Community Care and Assisted Living Act (CCALA) requires that a licensee must operate a daycare in a manner that will promote the health, safety and dignity of persons in care (s. 7(1)(b)).
The Child Care Licensing Regulation (CCLR) says a licensed daycare must ensure that a healthy and safe environment is provided at all times while children are under the supervision of employees” (CCLR, s. 13(1)) and that children do not have access to hazardous substances (CCLR, s. 17).
The Occupational Health and Safety Regulation (OHSR) has detailed provisions covering ionizing radiation (s. 7.17 to 7.25). If a workplace ensures that radon levels are under 200 Bq/m3 this will approximate these standards.
The OHSR also has general requirements on avoiding risk of injury or occupational disease(s. 2.2) Ontario’s guidance on Radon in the Workplace has adopted the formal policy that the ‘general duty clauses’ includes protection from radon over 200 Bq/m3.