Radon in Spain
Official radon data, regulations and resources
National reference level
300 Bq/m³
Competent authority
Regions
Álava
7 municipalities
Albacete
3 municipalities
Almería
43 municipalities · 23 high-risk
Ávila
242 municipalities · 151 high-risk
Badajoz
143 municipalities · 86 high-risk
Islas Baleares
25 municipalities
Barcelona
162 municipalities · 56 high-risk
Burgos
100 municipalities
Cáceres
208 municipalities · 189 high-risk
Castellón
14 municipalities
Ciudad Real
54 municipalities · 14 high-risk
Córdoba
33 municipalities · 22 high-risk
A Coruña
90 municipalities · 88 high-risk
Cuenca
21 municipalities
Girona
182 municipalities · 66 high-risk
Granada
53 municipalities · 23 high-risk
Guadalajara
111 municipalities · 14 high-risk
Gipuzkoa
70 municipalities
Huelva
38 municipalities · 8 high-risk
Huesca
72 municipalities · 13 high-risk
Jaén
24 municipalities · 4 high-risk
León
115 municipalities · 22 high-risk
Lleida
113 municipalities · 42 high-risk
La Rioja
70 municipalities
Lugo
67 municipalities · 56 high-risk
Madrid
144 municipalities · 85 high-risk
Málaga
21 municipalities
Murcia
3 municipalities
Navarra
77 municipalities · 12 high-risk
Ourense
92 municipalities · 82 high-risk
Asturias
49 municipalities · 11 high-risk
Palencia
57 municipalities
Las Palmas
21 municipalities · 21 high-risk
Pontevedra
60 municipalities · 58 high-risk
Salamanca
359 municipalities · 233 high-risk
Santa Cruz de Tenerife
29 municipalities · 29 high-risk
Cantabria
51 municipalities · 1 high-risk
Segovia
163 municipalities · 51 high-risk
Sevilla
23 municipalities · 9 high-risk
Soria
72 municipalities
Tarragona
43 municipalities · 11 high-risk
Teruel
90 municipalities
Toledo
152 municipalities · 99 high-risk
Valencia
5 municipalities
Valladolid
102 municipalities
Bizkaia
32 municipalities
Zamora
227 municipalities · 63 high-risk
Zaragoza
109 municipalities
Ceuta
1 municipalities · 1 high-risk
Regulations & obligations
Dwellings
Reference level of 300 Bq/m³ applies. Measurement recommended in radon priority areas. If exceeded, mitigation measures should be implemented.
Workplaces
Mandatory measurement in workplaces located in radon priority areas (Category I). Reference level 300 Bq/m³. If exceeded, employer must implement mitigation measures and verify effectiveness.
Public buildings & schools
Public buildings and schools in radon priority areas must conduct measurements. Reference level 300 Bq/m³. Mitigation required if exceeded.
New construction
New buildings in radon priority areas must include radon protection measures (CTE DB-HS6). Radon barrier required in Zone II. Design to achieve levels below 300 Bq/m³.
Measurement protocols
Professional services
UTPR
Technical Units of Radiological Protection
CSN-authorized entities for workplace radon measurement under IS-47
Accredited by: CSN
SPA/SPP
Prevention Services (Internal/External)
Occupational risk prevention services handling workplace radon assessment under LPRL
ENAC-Accredited ISO 17025 Laboratories
ENAC-accredited laboratories for radon detector analysis
Accredited by: ENAC
Radon Mitigation Companies
Companies specializing in radon reduction systems and CTE DB-HS6 compliance
Radon Barrier Membranes & Sheets
Manufacturers and distributors of radon barrier membranes, sheets and geotextiles for new construction (CTE DB-HS6) and renovation projects
Sub-Slab Depressurization & Extraction Systems
Manufacturers and suppliers of sub-slab depressurization kits, radon extraction fans, piping systems and sump components
Radon Barrier Paints & Coatings
Manufacturers and distributors of specialized radon barrier paints, sealant coatings and anti-radon surface treatments for walls and floors
Mechanical Ventilation Systems for Radon
Manufacturers and suppliers of mechanical ventilation systems for radon reduction: positive input ventilation (PIV), heat recovery ventilation (HRV) and controlled mechanical ventilation (CMV)
Radon Sealants & Airtightness Products
Manufacturers and distributors of specialized sealants, expanding foams, gaskets and airtightness products for sealing radon entry points at joints, pipe penetrations and cracks
Ventilated Crawl Spaces & Cavity Systems
Manufacturers and suppliers of prefabricated ventilated crawl space systems, cavity formers and sanitary floor solutions for radon prevention in new construction
How radon is measured in Spain
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 3 months
Recommended season
October–April (heating season)
Detector placement
Minimum 2 detectors, ground floor or basement, away from draughts and heat sources
Laboratory requirements
ISO 17025 accredited laboratory (ENAC)
Reference standard: ISO 11665-4 · CTE DB-HS6; IS-47 CSN
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.
Learn how to testMajor Cities
Madrid
3,255,944 inhabitants
Barcelona
1,686,208 inhabitants
Valencia
824,340 inhabitants
Zaragoza
686,986 inhabitants
Sevilla
686,741 inhabitants
Málaga
592,346 inhabitants
Murcia
471,982 inhabitants
Palma
438,234 inhabitants
Las Palmas de Gran Canaria
383,516 inhabitants
Alicante
348,901 inhabitants
Bilbao
347,342 inhabitants
Córdoba
325,708 inhabitants
Valladolid
300,618 inhabitants
Vigo
293,642 inhabitantsHigh (geology estimate)
Gijón
271,780 inhabitants
Gasteiz / Vitoria
257,407 inhabitants
L'Hospitalet de Llobregat
257,038 inhabitants
A Coruña
250,438 inhabitantsHigh (geology estimate)
Elche
234,765 inhabitants
Granada
233,532 inhabitants