What REALTORS® in Canada Need to Know About Radon
Radon is found in every home in Canada. It’s an invisible, radioactive gas that comes from the ground. When radon builds up inside, it can be dangerous.
Long-term exposure to high radon levels is the number one cause of lung cancer in non-smokers. Lung cancer is the most common cancer in Canada, and survival rates are low.
The only way to know if a home has high radon levels is to test.
What is radon?
Radon is a radioactive gas that’s odourless, colourless, and tasteless. It’s produced by the breakdown of uranium found in sediment (soil), rocks, and water. When radon is released into the atmosphere it gets diluted and poses negligible risk to human health. If radon accumulates inside a home, it can pose a serious health risk.
Radon is found throughout Canada, but concentrations differ depending on the composition of the bedrock or sediment.
How common is radon in Canada?
The 2024 Cross-Canada Radon Survey found that 1 in 5 homes in Canada have high levels of radon. That means this is an issue REALTORS® and home buyers need to be aware of.
How to test for radon
There are two main ways to test a home for radon:
- Buy a do-it-yourself (DIY) radon test kit.
- Hire a certified radon measurement professional.
To get an accurate result, it’s important to do a long-term test (at least three months).
If your client chooses a DIY test kit, they need to follow the instructions carefully when setting it up.
Some homeowners may want to buy an Electronic Radon Monitor (ERM). If so, they should make sure it’s one that has passed Canadian National Radon Proficiency Program (C-NRPP) performance testing. Health Canada has recalled more than 12 ERMs for poor and inaccurate results, and more are in the process of being added to the recall list. Choosing a C-NRPP-approved ERM is the best way to ensure accurate results.
Changes to the National Building Code (NBC) in 2025
Important radon updates are coming to the National Building Code in 2025. All new homes will now require a Passive Soil Depressurization (PSD) system, also called a passive radon stack.
Here’s how it works:
- A vertical pipe runs from under the foundation to above the roof.
- Natural airflow moves radon gas through the pipe and releases it outdoors, before it enters the home.
These systems can lower radon levels by 40–90%. If more reduction is needed, a fan can be added to turn the system into an Active Sub-Slab Depressurization (ASD) system.
Another change in 2025 is the launch of the National Building Code harmonization model. This will help provinces and territories align their building codes with the national standard. The goal is to have a consistent building code across the country.
Resources for REALTORS®
Health Canada and Take Action on Radon offer free printed publications that REALTORS® can order and share with clients. These include brochures and fact sheets that explain what radon is, why testing matters, how to test, and how to reduce high levels.
November is Radon Action Month in Canada, a perfect time to raise awareness and start conversations with clients.
REALTORS® can also point clients to Test4Radon.ca, an interactive website that provides answers to common questions, guidance on testing and mitigation, and helpful digital reminders—like when to order a test kit and when to send it back to the lab after the three-month testing period.
By understanding radon risks and sharing this knowledge with clients, REALTORS® can protect home buyers’ health and build trust as informed, reliable advisors in the Canadian housing market.
For more information visit www.canada.ca/radon.
