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Electromagnetic fields (EMFs) are produced wherever electricity is used, but only strong fields pose a risk. The Control of Electromagnetic Fields at Work Regulations 2016 (CEMFAW) came into force on 1 July 2016 and protect workers from the known direct and indirect effects of EMFs.
Effects of EMFs
- Direct effects: nerve or muscle stimulation, nausea, vertigo and tissue heating at high exposures
- Indirect effects: interference with active implants such as pacemakers and insulin pumps, projectile risks from ferromagnetic objects in strong static fields, and sparks or shocks from charged objects
Common sources
| Low risk, normally no further action | May need assessment |
|---|---|
| Office equipment, computers and lighting | Induction heating and melting |
| Most domestic-type appliances | Resistance and spot welding |
| Mobile phones and Wi-Fi | Radio frequency heating and drying |
| MRI scanners | |
| Broadcast and radar transmitters | |
| Electrolysis and large electrical installations |
Action levels and exposure limit values
The regulations set exposure limit values (ELVs), which must not be exceeded, and lower action levels (ALs). Exposure below the action levels shows the ELVs are met. Measuring internal body exposure is not practical, so employers normally compare the external field with the action levels using manufacturer data, standards or measurements.
What employers must do
- Identify whether any work involves EMFs that could exceed the action levels.
- Assess exposure, using manufacturer information or measurement if needed.
- Identify workers at particular risk: those with active implants such as pacemakers, those with passive metal implants, and pregnant workers.
- Eliminate or reduce the risk, for example with shielding, distance, interlocks, signs and restricted areas.
- Draw up an action plan if the ELVs could be exceeded.
- Give information and training, and arrange health surveillance or medical examination if a worker reports an effect.
There are limited exemptions, for example for MRI in healthcare where specific conditions are met.
The ACoP and official guidance
| Publication | Status | What it covers |
|---|---|---|
| HSG281 A guide to the Control of Electromagnetic Fields at Work Regulations 2016 | Guidance, not an ACoP | Sources, how to assess exposure against action levels, workers at particular risk and controls. |
An Approved Code of Practice (ACoP) has special legal status under section 16 of the Health and Safety at Work Act. If you are prosecuted and did not follow it, you must show that you met the law in some other way that was just as good. Guidance on Regulations has no special legal status, but inspectors refer to it and following it is normally enough to comply. Our guide to UK health and safety legislation lists every law and its ACoP or guidance in one place.
Training that helps
The NEBOSH National General Certificate covers physical hazards, including non-ionising radiation, and IOSH Managing Safely covers risk assessment for managers. Our electrical safety eLearning is a useful introduction for staff working with electrical plant.
Frequently asked questions
Do offices need an EMF assessment?
Normally no. Typical office equipment produces fields well below the action levels.
Who is at particular risk from EMFs?
Workers with active implants such as pacemakers, workers with passive metal implants, and pregnant workers.
When did the EMF Regulations come into force?
On 1 July 2016.
Is there an ACoP for EMFs?
No. HSE publishes HSG281, which is guidance on the regulations.
Read the source
The Control of Electromagnetic Fields at Work Regulations 2016 and HSE HSG281, A guide to the Control of Electromagnetic Fields at Work Regulations 2016. Facts checked on 7 October 2026.
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