What is the Action Level?

UK Health Security Agency recommends that radon levels should be reduced in homes where the average is more than 200 becquerels per metre cubed (200 Bq m^-3). This recommendation has been endorsed by the Government.

This Action Level refers to the annual average concentration in a home, so radon measurements are carried out with two detectors (in a bedroom and living room) over three months, to average out short-term fluctuations.

What is the Target Level?

The Target Level of 100 Bq m^-3 is the ideal outcome for remediation works in existing buildings and protective measures in new buildings. If the result of a radon assessment is between the Target and Action Levels, action to reduce the level should be considered, especially if there is a smoker or ex-smoker in the home.