How is a radon test carried out?

A radon test is simple and non-invasive. Small plastic detectors — about the size of a biscuit — are placed in selected rooms, usually on the ground floor or basement, for a minimum of three months. These detectors absorb traces of radon gas and are then sent to a UKHSA-approved laboratory for analysis.

For quicker assessments, short-term tests (lasting 10–14 days) can be used, though they’re less reliable due to daily and seasonal variations.

The results are given in becquerels per cubic metre (Bq/m³) and compared against the UK action level of 300 Bq/m³. If levels are above this, further investigation and mitigation are advised.