Ontario Electrical Safety Code
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
Effective May 1, 2025
Ontario Electrical Safety Code (29th edition/2024)
The regulatory amendment to adopt the 2024 Ontario Electrical Safety Code (OESC or “the Code”) is effective 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.
2024 Ontario Amendments to the Canadian Electrical Code Part I, C22.1
2024 Modifications de l’Ontario au Code canadien de l’électricité, Première partie, C22.1
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.
For informational purposes only
View information about the 2021 Ontario Electrical Safety Code