EMF FAQs

Background and Regulations

What will the Control of Electromagnetic fields at Work Regulations (CEMFAW) Regulations mean for Dutyholders?

UK legislation, which was used previously to control the risks from EMFs, does not specifically require an assessment of the extent to which employees are being exposed to EMFs. The CEMFAW Regulations require dutyholders to assess the levels of EMFs to which their employees are exposed against a specific set of levels. However, many businesses will not have to significantly add to what they already do. This is either because their workplaces consist only of low level and safe sources of EMFs or because, in those workplaces where employees are exposed to higher levels of EMFs that might cause harm, EMF levels are already being assessed and robustly managed.

What effects from EMFs do the CEMFAW Regulations cover?

The Regulations relate to:

  • Sensory effects, which include; nausea, vertigo and flickering sensations in peripheral vision
  • Health effects, which include; shocks, nerve stimulation and heating effects
  • Indirect effects which include; interference with active or passive implanted or body-worn medical devices and uncontrolled attraction of ferromagnetic objects, ie the risk of injury from objects in a large static magnetic field being attracted to magnets in the workplace and hitting anyone in the way.

The Regulations do not address suggested long-term effects of exposure to EMFs, as there is currently no well-established scientific evidence of a causal relationship. Should scientific evidence emerge in the future, HSE will consider this, taking appropriate scientific advice from Public Health England.

Do the Regulations mean that I cannot undertake my current EMF related work activity?

No, HSE supports the continuation of all current EMF work activities where employees are properly protected and the requirements of the CEMFAW Regulations are met.

The majority of employers will not need to take any additional action to reduce the risk from EMFs, this is because either:

  • the levels of EMFs in most workplaces are already at safe levels; or
  • in workplaces where employees may be exposed to higher levels of EMFs, the levels and associated risks will already have been assessed and managed.

Do the Control of Electromagnetic fields at Work Regulations (CEMFAW) Regulations mean that I have to undertake lots of new assessments?

Many sources of EMF in the workplace produce such low levels of EMF that it is likely that, other than assessing exposure to EMFs, the measures you already have in place to manage risks will be sufficient to ensure employees are protected and to meet the requirements of these Regulations. The information contained in HSG 281 - The guide to the Control of Electromagnetic Fields at Work Regulations 2016, will help you with this.

ALs and ELVs

Why are there different ALs for electric and magnetic fields?

Electric fields and magnetic fields are separate quantities that are detected in different ways. They are really only considered together in the higher radiofrequency regions (ie > 100 kHz). Electric (E) fields are expressed in units of volts per metre (Vm-1) while magnetic fields are expressed either as a field strength (H) in ampères per metre (Am-1) or as magnetic flux density (B) in tesla (T). A magnetic flux density of 1 tesla is a very large field, so subdivisions are often used eg millitesla (mT) or microtesla (T) (thousandths or millionths of a tesla).

Do I have to ensure that my employees are not exposed to EMFs in excess of the sensory effect ELVs?

Exposure may exceed the sensory effect ELVs during work activities, as long as the applicable safety conditions are met and employees remain protected.

Why are there different ELVs for health and sensory effects? – What are they?

The levels of EMF that will lead to a worker experiencing a sensory effect are lower than those that will lead to a health effect.

Employees should not be exposed to EMFs which could lead to them experiencing health effects; compliance with the health effect ELVs is a way of ensuring this. This ELV includes a margin for safety to take account of factors such as an individual's height and stature.  However, it must always be remembered that the health ELVs are not a line between safe and dangerous. In most cases the onset of health effects will be a very weak effect, once the threshold has been exceeded. The health effects ELVs are set well below this onset of health effects threshold. The severity of the effect will increase with increasing exposure levels (ie these are deterministic effects).

If employees experience sensory effects, they will not suffer harm if there are no indirect consequences. For example, if someone is exposed while working on a structure at height, such that they are constantly experiencing micro-shocks, the distraction caused may lead to performance errors or to them losing grip on the structure or tools, injuring themselves or others.

If employees are likely to be exposed to EMFs that will lead to the sensory effects ELVs being exceeded, this is permissible, if certain safety conditions, specified in the Schedule to the CEMFAW Regulations, are met.

Exemptions

Why are the use of magnetic resonance imaging (MRI) for medical purposes and military activities not subject to the requirement to meet the exposure limit values (ELVs) stated in the of the Control of Electromagnetic fields at Work Regulations (CEMFAW) Regulations?

Compliance with the ELVs is disapplied for these activities because the EU EMF Directive allows member states to do this, however workers must remain protected from the risk of harm from EMFs.

For the use of MRI for medical purposes, the exposure of employees to EMFs must be as low as reasonably practicable and employees must be protected against the health effects and safety risks related to that exposure.

Subject to certain conditions, the exposure limit requirements of the CEMFAW Regulations do not apply to any military activity in respect of which a suitable and sufficient alternative exposure limitation system is in place (see HSG281 for more information).The military disapplication ensures that where British military personnel operate alongside military groups from non-EU states they can work to common standards that may not necessarily be the same as set out in the CEMFAW Regulations (regulation 4).

Employers whose work involves higher levels of EMFs should already have in place risk assessments and proportionate protection systems for the health and safety of their workers.

What is meant by 'exemptions must be limited in time'?

To make sure that an exemption is still needed, HSE will periodically review the position. Changes in the work activity process or the installation of new equipment that incorporates engineering controls could make an exemption unnecessary. As technology develops and older equipment is replaced, it is probable that an exemption will not be required where equipment using the new technology is used.

To ensure the requirement for an exemption is reviewed, exemptions will be limited for a certain length of time and the review will check that the activity still needs to be carried out and meets the criteria for an exemption.

If the position has not changed, then the exemption may be extended.

The disapplication relating to the use of MRI for medical purposes requires the exposure of employees to EMFs to be as low as reasonably practicable, what does this mean?

You must ensure that:

  • Even though exposure is permitted to be above the ELVs, dutyholders are still required to bring exposures to the lowest levels they can, ie that the ELVs are exceeded only to the lowest extent reasonably practicable, and therefore, that the risk that any unintended increase in exposure, which could cause harm is minimised and;
  • employees must be protected against the health effects and safety risks posed by those exposures.

Will an exemption to the Regulations be needed in respect of electrical fault conditions?

Faults, by definition, are unplanned and unpredictable events. In terms of EMF exposure, it is generally not realistic or proportionate to expect employers to predict a fault condition, where or when a fault may occur, or how close an employee may be at the time of the transient (which may also be caused by switching events) current flow.

Exemptions are more appropriate for planned and predictable work activities in respect of which the employer can clearly demonstrate measures to ensure compliance with any exemption conditions. HSE's proportionate enforcement policy will reflect what can reasonably be expected of employers in these situations. In addition, how employers ensure safety in general during fault conditions will already be considered as part of normal enforcement activity.

Can HSE exempt work activities from certain exposure limits?

HSE may exempt specific work activities from the exposure limits stated in the Regulations; any exemption is subject to certain safety conditions being met. Any exemption can be revoked or amended by HSE at any time. Full information on exemptions is available in HSG 281 - The guide to the Control of Electromagnetic Fields at Work Regulations 2016. Details of activities for which an exemption is available can be found on the exemption page.

How will industry know if an exemption applies to their work activity?

Regulation 13(1) of CEMFAW Regulations grants the Health and Safety Executive (HSE) power to exempt employers from the exposure limits contained in the Regulations. An exemption would only be necessary if your work activity cannot comply with the health effect ELVs.  Any exemption will be subject to safety conditions being met. It should be remembered that exposure limits are not a line between safe and dangerous exposures.

If HSE exempts an activity from the exposure limits, you as the employer must ensure that:

  • exposure is as low as reasonably practicable; even though exposure is permitted to be above the ELVs you are still required to bring exposure to the lowest levels you can, ie you must ensure the ELVs are exceeded to the lowest extent reasonably practicable. To help you with this you may wish to consider the information HSG281 under 'Is an action plan needed?', and;
  • your employees are protected against the health effects and safety risks posed by that exposure.

Full details of exempted activities and the safety conditions can be found on the exemption page.

Exposure Assessment

HSE guidance (HSG281) states that I can use information already available to me - such as emission information and other safety-related data provided by the manufacturer or distributor of equipment in my workplace - to help me in my exposure assessment. What do I do if I am unable to access this because, for example, the equipment is quite old?

Manufacturers and suppliers of new equipment, most of which will be subject to EU product safety regulations, have to ensure that the equipment is safe – and deal with the risks associated with (radiation) EMF; this information should be covered in the technical file and provided to the user as part of the user instructions etc.

For older equipment, which may have been supplied before product directives came into force, there is a general duty on the manufacturer/supplier to ensure that the equipment (articles for use at work) are safe and without risks. This would include providing the end user with relevant information about radiation/EMF.

You may also wish to consider other, more current equipment for which emission data are available and compare the operating characteristics of this with your older equipment. You can then make an assessment of the degree of exposure and whether you will need additional information to ensure the safety of your employees.

We recommend that you consult with your supplier if you feel that you need more information to help you prepare your exposure assessment.

Will I need to undertake measurements to complete my exposure assessment?

In most cases, you should be able to find enough information from current sources to allow you to undertake a suitable and sufficient assessment of the EMF levels. For many businesses, consulting tables 2, 3, 5, 6 and 7 in HSG 281 - The guide to the Control of Electromagnetic Fields at Work Regulations 2016, may be enough to demonstrate that exposure does not exceed the ELVs.

Will I need to use a consultant to complete my exposure assessment?

No, in most cases, you should be able to find enough information from current sources to allow you to undertake a suitable and sufficient assessment of the EMF levels. For many businesses, consulting HSG 281 - The guide to Electromagnetic Fields at Work Regulations 2016, will be enough to demonstrate that exposure does not exceed the ELVs. HSG 281 also includes links to other useful information such as the EC Non-binding guide to good practice for implementing Directive 2013/35/EU: Electromagnetic fields.

Measurements or calculations should only be needed by those employers using the more powerful equipment or highest currents, where pre-existing information is insufficient to determine that the health effects ELVs are not exceeded.

General

I work in a job where I may be exposed to EMFs, am I at risk?

Everyone is exposed to EMFs all the time: at home, in work and in the general environment. Effects from EMFs are extremely rare and will not occur in most day-to-day work situations. It is your employer's responsibility to assess and manage the health and safety risks at your workplace by conducting a suitable and sufficient risk assessment and ensure that employees, who are likely to be exposed to risks from EMFs at work, and/or their representatives, receive any necessary information and training relating to the outcome of the risk assessment.

I am a member of the public who wants to know more about EMFs

HSE provides information and guidance on EMFs for employees and employers. Public Health England (PHE) provides information on EMFs and public health.

PHE's role is to provide an integrated approach to protecting UK public health through the provision of support and advice. Public Health England has the statutory function of giving advice to Government on all radiation matters.

Has HSE been involved in any research on EMFs?

HSE has been involved in the following:

Health surveillance

If the CEMFAW Regulations only relate to short-term effects resulting from exposure to EMFs, when would health surveillance be appropriate?

While it is possible to incur health effects, such as heating effects leading to a rise in the core body temperature or localised limb heating from exposure to EMFs, there is no well-established scientific evidence of long-term health effects.

This means that health surveillance is only likely to be necessary in very limited circumstances eg where an employee is exposed to EMFs in excess of any health-effect ELVs and reports experiencing a health effect.

In such a case, you must make sure that health surveillance and medical examinations are provided as appropriate.

Any health surveillance and/or medical examination must be provided during hours chosen by the employee and a suitable record kept of any health surveillance and medical examinations undertaken.

Rail Industry

I operate railway rolling stock. How do I assess the EMF risk in cases where the rolling stock is old and emission information is not available from the manufacturer?

In some cases the manufacturer/supplier may be able to provide information and data from the associated CE technical file. However, in many cases you will not need to obtain this information and should be able to follow the guidance provided by the Railway Safety and Standards Board, which provides case studies, based on modelling, measurements and qualitative assessments performed in and around railway infrastructure and rolling stock. The guidance can be found here: Rail Industry Guidance Note on the Application of the Control of Electromagnetic Fields Regulations 2016

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Updated 2021-03-26