With the implementation of Ontario Regulation 157/25, constructors across Ontario must clearly understand when an Automated External Defibrillator (AED) is legally required on a construction project. The regulation establishes two specific thresholds that determine whether AED compliance is mandatory, and both must be met for the requirement to apply.
An AED is required when a construction project regularly employs 20 or more workers and the project is expected to last three months or longer. When these conditions are met, AED compliance becomes enforceable as of January 1, 2026, under the Occupational Health and Safety Act (OHSA). This means that many medium to large construction projects—such as commercial builds, infrastructure work, institutional projects, and long-term residential developments—will fall within the scope of the regulation.
It is important to understand that inspectors assess actual job-site conditions, not just original project plans. A project that initially begins with fewer workers or a shorter timeline may later exceed the threshold due to staffing increases, scope changes, or scheduling delays. When this occurs, AED compliance becomes mandatory, even if the requirement was not anticipated at the outset. Waiting until an inspection to address AED requirements may expose constructors to enforcement orders or project disruptions.
Proactive planning is therefore essential. Evaluating workforce size, anticipated project duration, and emergency response considerations early allows constructors to implement AED compliance in a structured and cost-effective manner. This includes selecting a compliant AED, identifying appropriate placement, arranging training, and establishing inspection procedures before enforcement begins.
Ontario construction companies can review Health Canada–licensed AEDs suitable for construction environmentsthrough The AEDShop’s construction collection at:
👉 https://aedshop.ca/collections/construction-sites
📖 Official Regulation (O. Reg. 157/25):
https://www.ontario.ca/laws/regulation/r25157