Electromagnetic fields and radiation
OC 497/1
This 2-part OC gives advice about occupational sources of electromagnetic fields and radiation, describes the possible risks to health and indicates what inspectors should expect of employers by way of assessment and management of the risks. The attached Information Document may be copied and given to interested persons outside HSE.
Introduction
1 Electromagnetic fields (EMFs) and radiation are a form of non-ionising radiation that ranges from static electric and magnetic fields through to the radiofrequency (RF) and microwave region. Electromagnetic fields arise whenever electrical energy is used, including for industrial, commercial and medical purposes and they are also present around all wires carrying electricity. The strength of the magnetic field depends on the size of the current that is flowing whilst the strength of the electric field depends on the voltage applied. Electric fields are easily shielded whereas magnetic fields are not. The strength of a field is important when considering health effects.
2 The National Radiological Protection Board (NRPB) has produced guidelines which make recommendations on restrictions on exposure to EMFs to prevent adverse effects on health. They refer to 'basic restrictions' and 'investigation levels' which are designed to prevent acute harmful effects of exposure. The guidelines apply equally to workers and members of the public. This OC is not concerned with ionising and optical radiation, and any advice on electromagnetic compatibility and RF ignition should be obtained from RSG/SSG electrical specialists. Exposures of patients undergoing medical treatment and examination are excluded and restriction of their exposure will be a matter for clinical judgement.
Advice
3 The NRPB has the statutory function to advise Government on all scientific matters relating to radiation and NRPB's recommendations have been accepted by Government as the basis for the management of health risks from EMFs. In particular, HSE expects employers to comply with the recommendations as evidence that they have carried out their duties under the Health and Safety at Work etc Act 1974 and the Management of Health and Safety at Work Regulations 1992 (MHSW Regulations). Regulation 3 of MHSW Regulations requires employers to make a suitable and sufficient assessment of risks to health and safety. The purpose of the assessment is to enable the employer to determine what measures should be taken to adequately control the risks arising out of the work activity.
Action by inspectors
4 Inspectors should be alert to the processes described in the ID at Table 2 which may produce EMFs which exceed the NRPB investigation levels. Inspectors may provide copies of the ID to anyone requiring advice to assist them in the assessment and control of exposure to EMFs.
5 Where exposures to EMFs are likely to be at or above the investigation levels, inspectors may ask employers to demonstrate that they have carried out a risk assessment to determine whether the investigation levels have been reached, and if so, have either calculated that the basic restrictions have not been exceeded or have introduced adequate control measures.
Enquiries
6 Technical enquiries from operational inspectors should be directed to the local FOD RSG/SSG radiation specialists.
Date first issued: 28 May 1999
(220/FOD/1019/1999)
Disc ref: J:\Editors\intranet\ocfiles\497_1.sam