Radon in Finland
Official radon data, regulations and resources
National reference level
300 Bq/m³
Competent authority
Radiation and Nuclear Safety Authority (STUK)
What should you do?
Regardless of the official classification, the only way to know the radon level in a specific building is to measure it. A long-term test (at least 3 months) is recommended. You can either test yourself with passive detectors or hire a certified professional.
Regulations & obligations
Dwellings
Reference level 300 Bq/m³ for existing dwellings (updating to 200 Bq/m³ effective 2026).
Workplaces
Reference level 300 Bq/m³ for workplaces. Occupational exposure limits apply for extreme cases.
New construction
Design level 200 Bq/m³ for new dwellings. Buildings must be designed to not exceed this level.
Measurement protocols
Professional services
STUK-Approved Radon Measurement Services
STUK-approved and FINAS-accredited (ISO/IEC 17025) radon measurement services
Accredited by: STUK
Radon Mitigation Contractors
Contractors specializing in radon reduction including sub-slab depressurization and radon wells
Radon Consultants
Technical consultants for radon-safe new construction design targeting 200 Bq/m3
FINAS-Accredited Laboratories
FINAS-accredited ISO/IEC 17025 laboratories for radon measurement and analysis
Accredited by: FINAS
How radon is measured in Finland
Each country has its own official measurement protocol. Here is how radon testing works according to the national guidelines.
Measurement method
Alpha-track detectors (passive)
Minimum duration
At least 2 months during heating season
Recommended season
November–April (heating season)
Detector placement
Lowest occupied floor, at least 1 detector in main living space and 1 in bedroom
Laboratory requirements
STUK-approved measurement service
Reference standard: ST 12.1 (STUK) · Radiation Act 859/2018
How to test for radon yourself
Regardless of where you live, testing for radon is easy and affordable. A long-term measurement with passive detectors is the most reliable way to know your indoor radon level.
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