OESC: Ontario Electrical Safety Code

Last updated: September 2026

What the document actually is

The Ontario Electrical Safety Code is the Canadian Electrical Code, Part I, published by CSA as CSA C22.1, with Ontario specific amendments bound into the same book. CSA sells it as Ontario Electrical Safety Code, 29th Edition, 2024, and that catalogue entry states it contains the 26th edition of CEC Part I. The national code is a model document with no force of its own; Ontario adopts it by regulation, and that adoption is what makes it enforceable here.

The edition: 2024, 29th, in force 1 May 2025

This is the settled position, and it is the one every other page on this site defers to. The 2024 Ontario Electrical Safety Code came into force 1 May 2025. It is the 29th edition, and it contains the 26th edition of CEC Part I plus Ontario amendments. Work done after 1 May 2025 is judged against it. The CSA catalogue entry for the volume states the same thing, and it is the reference to cite.

ESA's own published material is not consistent about the number, with its FAQ pages calling the 2024 code the 28th edition while its newsroom pages call it the 29th, both giving the same in force date of 1 May 2025. That inconsistency is worth knowing about when you are reading ESA material, but it does not make the edition number unknown. The other half of the confusion is that the book carries two edition numbers at once, its own and the CEC Part I edition bound inside it, so quote both and the in force date together and you will not be misread.

Who makes it, who adopts it, who enforces it

CSA writes and publishes it. Ontario adopts it. The Electrical Safety Authority enforces it, and ESA inspectors are the ones who accept or reject your wiring. That is a separate authority from both the municipal building department and the fire department, which is why one fire alarm job produces three sets of paperwork and three people who can stop it.

What it covers for fire alarm work

Section 32 is the part you need. It covers local fire alarm systems, permanently connected smoke and carbon monoxide alarms, and fire pumps, and it is a supplementary section, meaning it amends the general rules of the code rather than standing alone. You read it together with the general rules, not instead of them.

The requirements that catch people out:

• The panel gets a dedicated circuit, with a disconnect that is permanently marked, red, and lockable in the ON position.
• Conductors are copper, insulation rated not less than 300 V. Ordinary Class 2 control cable is often rated lower.
• Minimum No. 16 AWG for individual insulated conductors pulled into a raceway, No. 19 AWG for conductors laid in one.
• Fire alarm conductors are kept independent of all other wiring, with defined exceptions at connection points.
• Because a fire alarm is a safety control device, the circuit is treated as Class 1 regardless of voltage or power limitation. Class 2 instincts carried over from ordinary 24 V control wiring do not apply.

The detail, with a plain warning about which rule numbers are attested and which are not, is in what CEC Section 32 requires. The cable side, including the CSA C22.2 No. 208 product standard behind the FAS markings and why a CSA FT number is not an American CMP or CMR rating, is in fire alarm cable in Canada.

What it does not govern

It does not decide whether the building needs a fire alarm system, how the system is zoned, how it must behave under a single fault, or where a detector goes. Those come from the Ontario Building Code and from CAN/ULC-S524.

You can satisfy one and fail the other, and both inspections are real. A system with perfect S524 architecture that shares a raceway with a lighting circuit fails the electrical inspection. A flawlessly executed dedicated circuit feeding a panel with no fault tolerance across zones fails the other one.

What it costs, and what is free

The code itself is a paid CSA publication. There is no free official copy, and any site offering one is not offering the current document. Budget for it.

What is free is ESA's own material: its bulletins, and its list of recognized certification marks, which tells you which approval marks are accepted in Ontario. Useful, and not a substitute for the code. Every Canadian fire alarm document, what it costs and where to get it, is listed in where to get each Canadian code free.

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Fire Alarm Academy provides educational content only. It does not confer any certification, licence or credential, and it is not affiliated with, endorsed by, or accredited by the Canadian Fire Alarm Association, the Electrical Contractors Association of Ontario, ULC Standards, UL Standards and Engagement, CSA Group, the Electrical Safety Authority, any authority having jurisdiction, or any manufacturer. Always work from the edition of any standard adopted by your authority having jurisdiction.