Workplace and Schools
The UK Ionising Radiations Regulations (1999)* govern the permitted exposure to radiation in the workplace. These regulations were designed to protect those working with radiation such as workers in the nuclear industry or medical professionals who come into regular contact with radiation as part of medical diagnosis and radiotherapy. However, apart from the known lung cancer risk, the regulatory health safety issue with radon is that the potential radiation dose received in the workplace could exceed what is permitted for radiation workers.
In terms of radiation dose, a radon gas level of 400 Bq per cubic metre would correspond to the maximum permissible under the UK 1999 Ionising Radiations Regulations. The level is twice the Action Level for domestic radon because unlike time spent in the home it is assumed that people spend less time at work, around 40 hours per week, excluding holidays.
Unlike domestic exposure, legal responsibility for the radiation dose received from exposure to radon gas in the workplace is regulated by the Health and Safety Executive, the HSE.
Under UK regulations all employers must review the potential radon hazard in their premises. The HSE takes radon gas seriously, amongst their advice they say: "HSE and some Local Authorities are aware of some workplaces such as factories and shops that have measured radon levels significantly in excess of the 400 Bq per cubic metre action level. Worst cases have shown levels over 17,000 Bq per cubic metre !"
Radosure provides a routine radon gas monitoring service for employers including a written report and our service is fully validated by the HPA. Detectors should normally be put in place for at least three months.
Working areas at risk from elevated levels of radon
Apart from the known Radon Affected Areas, ground and especially below ground level premises are likely to harbour above average levels of radon gas. In most cases it is unnecessary to carry out monitoring above the ground floor. The number of detectors depends on the area of the premises. The guidelines below follow the advice given by the HPA.
Type of premises:
Small premises
These include offices, shops, pubs, restaurants, night-clubs, banks and professional practices.
We recommend monitoring using one detector per 100 square metre of the ground floor area.
Large premises
Open plan areas should be monitored using one detector every 250 square metre. Larger industrial areas such as warehouses should be monitored using one detector every 500 square metre.
Basement premises
Basement areas of offices, shops, pubs, restaurants and night-clubs could habour elevated radon. Radon gas monitoring is recommended in all basement rooms and working areas.
Underground premises
Underground working areas are those most likely to harbour radon gas levels of concern. We recommend that one detector in each room or area that is likely to be occupied even if this is not on a full time basis.
In addition to mines and caves which are known to harbour radon, underground cafés bookshops, pubs, restaurants and night-clubs should be tested for radon.
Our charge for Radosure detectors starts at 17.30 + VAT = 19.90.
As an employer, how should I view the results of radon gas measurements?
The HSE has made the statement on radon risk assessment:
Reviewing radon risk assessment
As with all health and safety risk assessments, their applicability should be kept under review. Where significant changes are made to the fabric of a building or to the work processes carried out within it, then the need to remeasure the radon levels should be considered. In any case, it is still good practice to assign a maximum period upon which remeasurement of the radon levels will occur. Whilst it is the employer, in consultation with the Radiation Protection Adviser where appropriate, who is best placed to determine the frequency of any remeasurements, HSE suggests the following guidelines:
“where radon levels were found to be significantly less than 400 Bq per cubic metre at the initial measurement, the period of re-measurement might be of the order of once every 10 years; where radon levels were just below 400 Bq per cubic metre at the initial measurement, the suggested period for re-measurement will be less than 10 years; where radon levels were above 400 Bq per cubic metre at the initial measurement and measures have been taken to reduce radon exposures (such as engineered systems or occupancy restrictions), the re-measurement periods may need to be significantly more frequent in order to verify their continuing effectiveness.”
You will find more information on radon in the workplace from the HSE website:
http://www.hse.gov.uk/radiation/ionising/radon.htm#reviewingradon
*Statutory Instrument 1999 No. 3232