Radon in the workplace

The amount of radon that collects in a building depends on its location, structure and how it is used. Work environments vary greatly in size and nature, but excessive radon levels can occur in almost any type of workplace.

Employers are required by law to assess any risks to their staff while at work. This should include potential radon exposures and usually requires testing in any workplace premesis that are in radon Affected Areas.

In workplaces such as offices, where hazards are normally low, radon can be the largest occupational health risk. Furthermore, employees who live nearby may also be exposed to a high radon level while at home. Wider awareness of radon can, therefore, benefit employees.

Radon comes from the ground, so the construction of the floor and its integrity can affect the radon level indoors.

Once inside the building, the level of radon depends on the amount of ventilation and the nature of the work. Radon levels can vary greatly within a large building and so individual risk depends on time spent in different areas.

A simple test pack for radon can be ordered through this website. Testing is generally undertaken in ground floor rooms that are used routinely. Other rooms, on higher floors or those in which people spend little time, do not generally need to be tested. All workplaces in radon Affected Areas should be tested, unless a detailed assessment shows good reason to expect the radon level to be low.



If a radon level in any part of a workplace exceeds 400 Becquerels per cubic metre (Bq m^-3), the employer is obliged to take action. They must inform staff of their risk and nominate a responsible member of staff to oversee progress with protection measures.

HPA recommends a five-point plan for employers with premises in radon Affected Areas:

• Measurement Test for radon on the ground floor and occupied basements
• Surveillance Continue monitoring until remedial action is complete
• Risk assessment Set priorities for action based on radon levels
• Mitigation Complete remedial action within six months
• Maintenance Conduct periodic testing and routine checks

The HPA offers a surveillance service, which incorporates all these elements, and can also advise on more complex protection issues where required.

To download a copy of this page as a leaflet in PDF format click here