Radon in France
Official radon data, regulations and resources
National reference level
300 Bq/m³
Competent authority
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 (reduced from 400 Bq/m³ in 2018). Property owners must reduce levels if exceeded. Measurement recommended in radon priority zones.
Workplaces
Mandatory measurement in workplaces located in radon priority zones. Reference level 300 Bq/m³. Special controls required if >1000 Bq/m³.
Public buildings & schools
Mandatory measurement in schools, hospitals and public buildings in priority zones. Actions required if >300 Bq/m³, special controls if >1000 Bq/m³ (Arrêté 2019).
New construction
New buildings in radon priority zones must include protection measures. Design to achieve levels below 300 Bq/m³.
Measurement protocols
Professional services
OA
Accredited Organizations (N1/N2)
ASNR-approved organizations for radon measurement at Level 1 (basic) or Level 2 (advanced)
Accredited by: ASNR
PCR
Competent Persons in Radiation Protection
ASNR-certified radiation protection specialists for workplaces including radon
Accredited by: ASNR
Radiation Protection Experts
Higher-level expertise roles for complex radon risk assessments as defined in EU Directive 2013/59/Euratom
Real Estate Diagnostic Professionals
COFRAC-certified professionals handling ERNMT preparation including radon risk disclosure for property transactions
Accredited by: COFRAC
How radon is measured in France
Each country has its own official measurement protocol. Here is how radon testing works according to the national guidelines.
Measurement method
Passive integrated radon dosimeters (DPPR/DSND type)
Minimum duration
At least 2 months, ideally September–April
Recommended season
September–April (heating season)
Detector placement
Ground floor or basement rooms, 1 detector per 50 m² of occupied space, away from ventilation
Laboratory requirements
COFRAC-accredited or ASN-approved laboratory
Reference standard: NF M 60-766 · Code de la santé publique; Décret 2018-434
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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