EN 62471 Photobiological Safety of Lamps and Lamp Systems

The European standard "EN 62471 Photobiological safety of lamps and lamp systems" provides guidance for the assessment of the photobiological safety of lamps and lamp systems, including luminaires. Specifically, this standard specifies exposure limits, a reference measurement technique, and a classification scheme for the assessment and control of photobiological hazards from all electrically driven incoherent broadband optical radiation sources, including LEDs but excluding lasers, in the wavelength range 200 nm to 3000 nm. This standard was developed by the International Commission on Illumination as CIE S 009.

EN 62471 is a European standard that assesses the potential hazards of optical radiation emitted by lamps and lamp systems, including light-emitting diodes (LEDs). This standard aligns with IEC 62471 "Photobiological safety of lamps and lamp systems" published by the International Electrotechnical Commission (IEC) and provides guidance for assessing the risks that light sources may pose to human eyes and skin.

The EN 62471 standard is particularly important for manufacturers of lighting products, display devices and systems containing optical radiation such as LEDs, UV lamps and lasers, ensuring that these products are safe for long-term human exposure.

The EN 62471 standard covers:

• Ultraviolet (UV), visible and infrared (IR) radiation emitted from lamps and lamp systems
• Both general lighting and non-general lighting applications
• Risk assessment of skin and eye exposure to optical radiation
• Classification of light sources according to risk groups

This standard does not apply to coherent sources (such as lasers) within the scope of IEC 60825-1.

Essentially, light sources are divided into four risk groups based on their photobiological hazard potential:

• RG 0 Exempt group: No photobiological hazard under normal exposure conditions.
• RG 1 Low risk: No danger under normal behavioral limitations.
• RG 2 Medium risk: No danger due to disgust reactions to bright light or thermal discomfort.
• RG 3 High risk: Danger even from momentary or short-term exposure; requires strict control or protection.

The main hazard categories assessed by the EN 62471 standard include:

• UV radiation hazard: Skin and eye risks from ultraviolet radiation.
• Blue light hazard: Risk of photochemical damage to the retina, particularly from high-intensity LEDs.
• Retinal thermal hazard: Risk of retinal burns from intense light sources.
• IR radiation hazard: Risk of eye or skin thermal damage from infrared radiation.

The EN 62471 standard stipulates the following for classifying a lamp or lamp system:

• Spectroradiometry measurements: Performed using a calibrated spectroradiometer.
• Measuring distances: Typically 200 mm from source unless otherwise stated.
• Integration time: Defined time intervals for exposure calculations (e.g. 10000 seconds for a long exposure).
• Evaluation criteria: Based on spectral irradiance (for skin) and brightness (for eyes), compared with defined exposure limits.

EN 62471 plays an important role in:

• Product safety assessment: For manufacturers to demonstrate compliance with health and safety regulations.
• Consumer protection: Preventing excessive exposure to harmful light, especially from high-output LEDs.
• Workplace safety: Ensuring that lighting systems in industrial and commercial environments do not pose photobiological hazards.
• E marking: Providing proof of conformity for lighting products under the low voltage directive (LVD) and the general product safety directive.

In short, the EN 62471 standard ensures that lighting products and lamp systems do not pose photobiological hazards to users. This standard is a fundamental reference for manufacturers and safety engineers working with artificial light sources, particularly as LED technology continues to evolve. Through clear risk group classification and scientific measurement protocols, this standard helps ensure safety in environments where artificial light is an integral part of daily life.

The test methods in EN 62471 are designed to assess the photobiological safety of lamps and lamp systems by measuring the optical radiation they emit and comparing it with defined exposure limits. These methods determine the risk to human eyes and skin from ultraviolet (UV), visible, and infrared (IR) radiation.

The test methods used in the EN 62471 standard are:

• Spectral measurement: This method measures the spectral irradiance and radiance of a light source. A calibrated spectroradiometer (for irradiance and radiance) is used for these measurements. Measurements are typically made between 200 nm and 3000 nm, covering UV, visible, and IR.
• Measurement geometry: The standard test distance is 200 mm unless the product is intended for closer or further use. Irradiance is measured on a flat detector surface. Irradiance is measured over a 1,7 mrad field of view (typical for retinal hazard assessments).
• Exposure time: This standard defines reference exposure times based on realistic exposure scenarios:
  • 10.000 seconds for general illumination (long exposure)
  • Shorter times (e.g. 100 sec, 1000 sec) for more intensive or specialized resources.

The measured irradiance or radiation is multiplied by time to calculate the total dose and compared with the limits.

• Hazard assessments and calculation methods: Each hazard group is evaluated according to specific equations and weighted functions. Within the standard, values ​​are given for UV skin and eye, blue light, retinal thermal, IR eye radiation, and thermal skin hazard types.
• Classification into groups: The measured results are compared with the exposure limit values ​​for each hazard. Based on the results, the lamp is classified as:
  • Exempt group
  • Risk group 1 (low risk)
  • Risk group 2 (medium risk)
  • Risk group 3 (high risk)

Each group corresponds to increasing levels of potential harm.

The supporting test conditions in the tests performed are as follows:

• Environmental conditions: Temperature, humidity and background light should be controlled.
• Stabilization period: Lamps should be operated until thermal stability is achieved before testing.
• Orientation: Tested in normal use position.

The EN 62471 standard test methods combine precise radiometric measurements with bioweighting functions to assess the safety of light-emitting products. These tests help manufacturers ensure that their products are safe for human exposure and meet European Union regulatory requirements.

Our organization, which has been supporting businesses across all sectors for years through a wide range of testing, measurement, analysis, and evaluation activities, has a strong team of employees who closely follow global developments in science and technology and are constantly improving themselves. In this context, we also provide testing services in accordance with the EN 62471 Photobiological Safety of Lamps and Lamp Systems standard.