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Photobiological safety of LED lights

What does photobiological safety mean?

Does a high proportion of blue light in LEDs endanger our health?

Many people are unsettled by negative headlines in connection with the threat to our health from LEDs and topics such as so-called photobiological safety. Frequently asked questions that arise particularly in relation to the right workplace light include:


  • Does LED light with a high proportion of blue light rob you of sleep?
  • Does LED light mess up the internal clock?

Is this uncertainty justified? Do LED workplace lights really pose a hazard to the eye? In order to pursue these questions, it is necessary to clarify from the ground up what effects blue light has on our body and how the risk of exposure to blue light from artificial light sources is to be classified.


Our internal clock is controlled by blue components in the LED light spectrum with a wavelength of around 480 nanometers. There are photoreceptors in the eye that specifically collect light of this wavelength. Such blue tones are particularly present in sunlight around midday. Bright, bluish and strong light slows down the release of the sleep hormone melatonin in our body. So if we have lighting with a high proportion of blue light during the day, this strengthens activity and encourages concentrated work. In the evening, however, these blue tones are missing in natural daylight, the light appears reddish and melatonin levels continually rise, making us tired.


Therefore, lighting with high illuminance and a high proportion of blue light should be avoided in the evening in order to avoid sleep disorders. So while a high proportion of blue light is certainly desirable during the day, it is certainly undesirable at night because it causes sleep disorders and can therefore be harmful to health. The use of light with a lower color temperature of around 3000 Kelvin is therefore recommended.

Color temperatures from warm white to daylight white
Color temperatures of a lamp from warm white to daylight white

The photobiological safety of light

Blue light hazard is the potential risk of photochemical damage to the retina caused by high-energy, blue visible light. It preferably occurs in Wave range between 400 nm and 500 nm on. This light can penetrate the cornea and reach the retina. This can cause irreversible damage to receptors.


In the discussion, it is often claimed that a high proportion of blue light in daylight-white LEDs endangers the retina and can therefore be harmful to health. But are LED workplace lights really a hazard to the eye?


A direct look at the sun (high proportion of blue light, extremely high luminance) can be harmful even after a short exposure. However, looking at the blue sky (very high proportion of blue light, low luminance) is possible without hesitation. The blue light component alone is therefore not responsible for possible damage to the eyes! Very high luminance levels and the duration of exposure must also be taken into account.


When LED workplace lights are used as intended, there is no danger to the eyes. The lamp head and articulated arm technology are designed in such a way that a direct view of the LED modules is avoided and the user is therefore not blinded. Furthermore, the LED modules are covered by plastic panes, so that even a quick glance at the light is harmless. But which user already does this? However, there are differences in the risk assessment of LED workplace lights.

Din-EN-62471 - Photobiological safety

The assessment of the risk of blue light exposure can be based on the European standard DIN-EN-62471 (in Germany DIN EN 62471) take place. Through various measurement regulations and evaluation standards, the light sources are assessed with regard to different hazards, among others photochemical retinal hazard (blue light hazard) assessed and divided into risk groups. The standard classifies the photobiological safety of light sources into the following risk groups (RG):


  • RG 0 “exempt” Are safe under all circumstances. No risk to the eye, even with permanent
    Looking towards the light source.
  • RG 1 "low risk" Low risk You can look into the light source for several minutes without risk
  • RG 2 "mod risk" Medium risk. You can look into the light source for a few seconds without any risk
  • RG 3 "high risk" Damage to the eye possible even with brief exposure
    Note: The sun would fall into the highest risk group 3 (RG3).


All of our RMD workplace lights belong to the company in terms of their photobiological safety risk groups 0 and are certified by Photometrik GmbH. They therefore fall into the group of artificial light sources with the highest photobiological safety. A health hazard, a disturbance of sleep and damage to the retina can therefore be ruled out. You can view the measurement report and the expert opinion below.

Measurement report

Certificate for the photobiological safety of RMD workplace lights

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