Ontario Electrical Safety Code

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Ontario Regulation 164/99: Electrical Safety Code

The Ontario Electrical Safety Code, Ontario Regulation 164/99, is comprised of the Canadian Electrical Code Part I (CEC) together with specific Ontario Amendments. Development of the CEC Part I is led by the Canadian Standards Association (CSA). It is developed in close consultation with volunteer technical committees and subcommittees reflecting expertise from across Canada, including ESA. After review, the provincial government then adopts the CEC, with additional amendments specific to Ontario. 

The Ontario Electrical Safety Code (OESC or “the Code”) is mostly a technical document and is prescriptive in approach. It describes in detail the standards for electrical installations, products and equipment in Ontario. ESA collaborates with safety partners on the development of the Code so each edition reflects applicable changes in technology and the market, feedback from stakeholders, technical reviews, and new safety insights.

You can decrease the risks of fire, shock, and electrocution by taking steps to ensure those who perform electrical work are qualified, competent and licensed.


Ontario Electrical Safety Code (28th edition/2021)

The Ministry approved the regulatory amendment to adopt the 2021 edition of the Ontario Electrical Safety Code (OESC or “the Code”), which came into effect May 5, 2022.  

The 28th edition of the Code includes the Canadian Electrical Code, Part 1, plus Ontario-specific amendments.

Ordering the Code

ESA has partnered with the CSA Group to offer the Code book and all ESA bulletins – which provide important updates and interpretations – together for one price. Visit CSA Group to order.

Note: Prices include access to the bulletins on CSA Communities website over the whole Code cycle

The 2021 edition of the OESC includes changes designed to enhance electrical safety and protect workers and the public, including: 

  • Provide requirements to support reduction in the potential for fires and the loss of animals in buildings housing livestock. 
  • Provide clear electrical safety installation requirements for Energy Storage Systems (ESS), and harmonize with other codes and standards. 
  • Requiring GFCI protection for all outdoor receptacles to mitigate the potential for electrical shock hazard 
  • Introduce guidance to electrical installations in flood hazard zones and when electrical equipment has been exposed to water to mitigate the potential risks. 
  • Keeping workers safe by requiring additional receptacle for mobile structures connected to transfer equipment. 
  • In Ontario, mitigate the potential for shock or electrocution when structures are erected in close proximity of customer owned powerlines.   
  • In Ontario, keep the reduced conductor sizes for services and feeders for dwelling units by following the current installation practice.

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