Glossary · Health & indoor air
Radon guideline (200 Bq/m³)
Also called: Canadian radon guideline · Health Canada guideline
Health Canada's radon guideline: fix your home if the yearly average where people spend time is above 200 Bq/m³, within a year, and sooner if higher.
What it means
Health Canada's guideline applies to the average annual level in a normal occupancy area, meaning any part of the home where someone spends more than 4 hours a day, and it also asks for levels as low as reasonably achievable. EPA's action level of 4 pCi/L, about 150 Bq/m³, is lower than Canada's guideline, so the same result can mean fix it now in the US and keep watching in Canada. Both agencies say lower is better.
Why it matters in an audit
Your test result is compared with these levels to decide whether a radon mitigation system is needed and how soon.
Typical numbers
Reference values with their sources. Your energy advisor’s report gives the figure for your own house.
| What | Value | Source |
|---|---|---|
| Canada (Health Canada, page modified 2025-09-24) | 200 Bq/m³ annual average in the normal occupancy area; act within 1 year, sooner the higher the level | canada.ca ↗ |
| US (EPA) | Fix at 4 pCi/L or more; consider fixing between 2 and 4 pCi/L | epa.gov ↗ |
| Same result, two answers | 150 Bq/m³ (about 4 pCi/L) is above EPA's action level but below Health Canada's guideline | Arithmetic (1 pCi/L = 37 Bq/m³) |