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BfS recommends using interior illumination with low portion of blue light

Year of issue 2018
Date 2018.11.30

Chain of lights with LEDs in the form of snow balls

Short days and the additional desire for comfort let apartments and houses shine in artificial light, especially in the pre-Christmas season. Approximately 73 percent of households are currently using LEDs as interior illumination; after the ban of the light bulb and the gradual disappearance of the energy-saving lamp, their market share rose from 1.4 percent to 61 percent in the last years. To avoid possible risks for the eye, the Federal Office for Radiation Protection recommends using artificial illumination with a low portion of blue light. As to whether and to what extent artificial illumination may lead to long-term effects, is the object of research.

Portrait Dr. Inge Paulini Dr. Inge PauliniBfS president Inge Paulini

Using illumination with a low portion of blue light

The white light in LEDs is mostly produced by a mixture of blue and the complementary colour, yellow. "Especially the energetic part of the light spectrum to include the colours blue and violet, can cause damage to the eye. Therefore, it is important to choose the right light colour, which is described by the colour temperature, among others. The warmer the light, the lower the portion of blue light," Inge Paulini, president of the Federal Office for Radiation Protection, emphasised.

Limit values protect

Blue light can cause damage to the retina, which may lead to eyesight impediment in the long run. Therefore, standards for lamps include defined values which take also into account the risk of damage to the retina. Within the scope of product safety, the producer is obliged to ensure that no damage occurs to the consumer under normal conditions of use. As a precautionary measure, however, one should do without excessive use of light sources with a high portion of blue light.

BfS recommendations for good lighting

  • Portion of blue light: The colour temperature in Kelvin provides good orientation for the estimation of the portion of blue light. The lower the colour temperature, i.e. the warmer the light, the lower the portion of blue light. Colour temperatures below 3,300 K are referred to as warm white, from 3,300 K to 5,300 K as neutral white, and above 5,300 K as daylight white or cold white.
  • Diligence in children's rooms: The eye lens of children is more permeable to short-wave light. Children receive more energetic light at the retina than adults. Lamps should be installed in such a way that especially little children cannot look directly into the light source. Furthermore, care should be taken in the case of children's toys equipped with LEDs.
  • Good lighting practice: What applies to children’s rooms, similarly applies to all living spaces: Lamps should generally be installed in such a way that it is impossible to look directly into the light source. Wall lamps and table lamps should additionally show lower luminence than ceiling lamps, since they are more often in direct sight. Furthermore, in LED panels the single LEDs should not be visible as bright point sources.

Advent and Christmas illumination no reason for concern

By the way, the typical Advent and Christmas illumination is not critical. Paulini emphasised: "Given that the lamps used in the usual Christmas illumination have a low radiance, there is no reason for concern. They are in the category "lowest risk group" which is safe for eyes Therefore, there is nothing in the way of enjoying an atmospheric Advent and Christmas illumination."

State of 2018.11.30

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