Ontario Electrical Safety Code

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NOTICE: The 2024 Ontario Electrical Safety Code comes into effect May 1, 2025. Get more information on the OESC (29th edition/2024) here.

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.

View the full O. Reg. 164/99: Electrical Safety Code

 

Ontario Electrical Safety Code (28th edition/2021)

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.

More information

Director's Order: Ontario Electrical Safety Code 28th Edition

2021 Ontario Amendments to the Canadian Electrical Code Part I, C22.1

2021 Modifications de l’Ontario au Code canadien de l’électricité, Première partie, C22.1

Q&A for Amendments to the Ontario Electrical Safety Code 28th Edition

2021 Ontario Amendment Consultation (for information purposes only)

 

Ontario Electrical Safety Code (29th edition/2024)

The Minister of Public and Business Service Delivery and Procurement approved the regulatory amendment to adopt the 2024 Ontario Electrical Safety Code (OESC or “the Code”), which comes into effect May 1, 2025.  

The 2024 edition of the Code includes the Canadian Electrical Code, Part I, plus several Ontario-specific amendments.  This new edition includes changes designed to enhance electrical safety and the public including: 

  • Enhancing Plan Review requirements to include submission for some electric vehicle supply equipment (EVSE) installations, and to include stand-alone electric-power-generating-equipment and systems.
  • Revising demand load calculation for single dwellings with EVSE loads.
  • Enabling electrification by recognizing other types of energy management systems in addition to electric vehicle energy management system.
  • Complete rewrite of the installation requirements of energy storage systems (ESS) at residential occupancies.
  • Preventing electrical shock hazards with additional requirements for outdoor receptacles for single dwellings. 
  • Preventing overloading in the future by requiring labelling of maximum residential load.
  • Enhancing bonding requirements for pools and hot tubs to prevent shock hazards.
  • Permitting insulated conductors within an enclosure when connected to different sources of voltage, with specific conditions.
  • Protecting the public with additional GFCI requirements for cords used at midways, carnivals, fairs, and festivals.
  • Increase in allowable voltages in electric vehicle supply equipment installations.

View the Ontario-specific amendments included in the 29th OESC Consultation

2024 Ontario Electrical Safety Code — Frequently Asked Questions

Ordering the Code

The new Code will be available for pre-order immediately (PDF), with hardcopy versions available in January 2025. The hardcopy of the Code book will be available for $243, as well as a PDF-version available for $217. These prices will include free access to the bulletins on CSA ONDemand website over the whole period of the Code cycle. 

ESA is partnering with the CSA Group to offer the Code book and all ESA bulletins – which provide important updates and interpretations – together for one price in a searchable, digital format for $217 – accessible on smart phones, tablets and desktops and compatible with Windows and iOS. This version will be available in Spring 2025.  

Order a copy of the 2024 OESC here.