Television and computer screens, like any other electrical office or household equipment, create low-frequency electric and magnetic fields. These are alternating fields of 50 Hz which is the regular power supply frequency. Harmonics (multiples of the basic frequency of 50 Hz) also occur but to a lesser extent. Static electric fields and higher-frequency electromagnetic fields up to the kilohertz range, are also created. Display tubes (cathode ray tubes) also produce low intensity X-rays. This, however, is almost completely screened by the tube housing.

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

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 smaller than those of tube screens.

General information:
The regulations governing computer operation have up to now only been introduced for ergonomic reasons such as long-term effects on operators´ eyes, illumination and design of the workplace such as the seating for staff working long hours. Regulations also cover psychological effects.

Similar restrictions govern the use of television. Special attention should be paid to the background lighting, and an appropriate viewing distance from the screen 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 reflects on the screen, the viewer’s eyes are under considerable strain. As a rule one can say: The bigger the screen, the bigger the viewing distance required.

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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 not only ergonomics, energy consumption and general ecological criteria, but also testing and assessment of emissions of electromagnetic fields. TCO Development recommends very low maximum emission limits for screens thus pursuing its ambitious aim of not increasing current exposure to electromagnetic fields (e.g., from various electric devices) in the workplace. This must be appreciated from a prevention 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.

The TCO standard is not mandatory for Germany. Tests are carried out according to various other standards (for example the EU regulations, ISO standards, and DIN regulations) which also define emission limits. Tests include interference resistance, freeness from flicker, contrast, convergence errors, and colour shifts, among others.

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From the radiation protection point of view, there are no objections to operate a television set or a computer in the bedroom. Since electric and magnetic fields decrease with increasing distance from the source observing a minimal distance of ca. 30 cm from the devices or an appropriate viewing distance from the television screen contributes to a precautionary reduction of exposure. Moreover devices should be completely disconnected during sleep and not be kept in standby mode. This is a precautionary measure and in addition helps saving energy.

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