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Elektromagnetische Felder

Display screens

  • Just like any other electrical office or household equipment, television and computer screens generate low-frequency electric and magnetic fields.
  • Modern flat screens do not have tubes and due to their design and operating mode they do not emit X-rays, and, moreover, their magnetic fields are considerably weaker than those of tube screens.
  • Up to today, occupational regulations related to work with display screen equipment have been established solely for ergonomic reasons.
  • TCO Development’s recommended maximum emission limits for screens are very low, thus pursuing TCO’s ambitious aim of not additionally increasing current exposure to electromagnetic fields at one’s workplace.
  • The TCO standard is not mandatory for Germany.

Display screens Display screen

Just like any other electrical office or household equipment, television and computer screens generate low-frequency electric and magnetic fields.

  • These are mainly alternating electric and magnetic fields with a frequency of 50 Hz, which is the regular power supply frequency.
  • To a lesser extent, harmonics (multiples of the basic frequency of 50 Hz) also occur.
  • Static electric fields and higher-frequency electromagnetic fields up to the kilohertz range are also generated.
  • Display tubes (cathode ray tubes) also produce weak X-rays. These, however, are almost completely screened due to the way the tube is constructed.

The intensity of the discharging non-ionising radiation and X-rays is so low that health risks can be ruled out when working at visual displays, and even if several devices are operated in the same room.

Magnetic fields of modern flat screens are considerably smaller

Modern flat screens do not have tubes and due to their design and operating mode they do not emit X-rays, and, moreover, their magnetic fields are considerably weaker than those of tube screens.

Regulations for ergonomic reasons

Up to today, occupational regulations related to work with display screen equipment have been established solely for ergonomic reasons such as

  • long-term effects on the worker’s eyes,
  • exposure to light,
  • design of the workplace when working in a seated position for a long time, and
  • psychological effects.

Similar advice should be followed when watching TV. Special attention should be paid to

  • the background lighting, and an
  • appropriate viewing distance from the screen.

A sufficient viewing distance should be adhered to in order to avoid eye damage. If for instance, the screen is much brighter than the background or if there are light reflections on the screen, the viewer’s eyes are under considerable strain.

As a rule, one can say: The bigger the screen, the longer the viewing distance should be.

TCO Standard for screens

TCO Development (an enterprise founded by TCO, the governing body of the Swedish trade unions for employees) grants approval for office equipment. Approval procedures involve

  • ergonomics,
  • energy consumption
  • general ecological criteria,
  • emissions of electromagnetic fields.

TCO Recommendations for maximum emissions of screens

TCO Development’s recommended maximum emission limits for screens are very low, thus pursuing TCO’s ambitious aim of not additionally increasing current exposure to electromagnetic fields (e.g., from various electric devices) at one’s workplace. This must be appreciated from a precautionary point of view.

The TCO-cachet is regularly updated and adapted to the state of technology. Today it is widespread, and a considerable number of screens adhere to a TCO standard. For further information, see the TCO Development web site.

TCO standard not mandatory for Germany

The TCO standard is not mandatory for Germany. Display screens, like any other electric devices, must adhere to the provisions of Germany’s legislation on product safety. Requirements related to emissions of electric and magnetic fields are contained in DIN regulations.

Additional requirements are included, for example, in ISO standards and concern, among others,

  • interference resistance,
  • (no) flickering,
  • contrast,
  • convergence errors, and
  • screen colours.
State of 2017.05.17

© Bundesamt für Strahlenschutz