Field and frequency range

Effects

Examples of activities and equipment

Static electric and static magnetic fields 0–1 Hz

Indirect effects: 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

Sensory effects: Nausea, vertigo, metallic taste in the mouth, flickering sensations (magnetophosphenes) in peripheral vision

Health effects: Micro shocks

MRI scanners (main magnet)

Electrochemical processes, e.g. industrial electrolysis, aluminium extraction

Nuclear magnetic resonance spectrometers

Electromagnetic lifting cranes

Electric vehicles (cars, underground trains)

Low frequency magnetic and electric fields: 1 Hz–10 MHz

Indirect effects: Interference with active or passive implanted or body-worn medical devices (more information is provided later in this guidance), electric shocks, causing electro-explosive devices to initiate, i.e. when used in close proximity to explosives that have an electrical means of initiation

Sparks caused by induced fields triggering fires or explosions where flammable fuels, vapours or gases are present

Sensory effects: Nausea, vertigo, metallic taste in the mouth, flickering sensations (magnetophosphenes)

Health effects: Nerve stimulation, effects on the central and peripheral nervous system of the body: tingling, muscle contraction, heart arrhythmia Contact currents caused by a person touching a conductive object in an EMF where one of them is grounded and the other is not, which can result in shocks or burns

High voltage power lines

Production and distribution of electricity

Welding (arc and spot)

Electrical arc furnaces

Industrial induction heating (e.g. large coils used around the site of a weld)

AM radio

Electric hand-held tools

Electric vehicles (cars, trains, trams, metros)

Magnetic resonance imaging (MRI) (switched gradient fields)

Intermediate frequency fields: 100 kHz–10 MHz

The health effects of both high and low frequencies can be experienced as detailed above and below (see also Annex 1)

Surgical diathermy

Broadcasting systems and devices (AM radio)

Anti-theft devices

Military and research radiofrequency systems

High frequency fields: 100 kHz–300 GHz

Indirect effects: Interference with active or passive implanted or body-worn medical devices (more information is provided later in this guidance), electric shocks, causing electro-explosive devices to initiate, i.e. when used in close proximity to explosives that have an electrical means of initiation

Sparks caused by induced fields triggering fires or explosions where flammable fuels, vapours or gases are present

MRI (RF coils)

Broadcasting and TV antennas

Radar and radio transmitters

Diathermy

Dielectric heating (e.g. vulcanising, plastics welding or microwave drying)

Anti-theft systems

100 kHz–300 GHz

Sensory effects: Auditory effects such as perception of clicks or buzzing caused by pulsed radar systems

Health effects: Thermal stress, heating effects leading to a rise in core body temperature or localised limb heating (e.g. knees or ankles)

Contact with charged conducting bodies can lead to RF shock or deep tissue burns (see also Annex 1)

Broadcasting and TV antennas

Radar and radio transmitters

Diathermy

Dielectric heating (e.g. vulcanising, plastics welding or microwave drying)

Anti-theft systems