Laser classes
Laser technology is increasingly being used in warning systems, for example to project lines, symbols or zones directly onto the hall floor. Similar to warning zone lights with LED technology, these warning systems do not create any physical barriers, but are visually very striking and robust against soiling or light conditions. At the same time, laser products are subject to specific safety requirements that differ significantly from LED systems.
The so-called laser class is decisive for the risk assessment. It determines how dangerous the radiation can be to the eyes or skin and what protective measures are required.
Laser classes at a glance (according to DIN EN 60825- 1)
| Class | Meaning | Safety note |
|---|---|---|
| Class 1 | Safe under all normal conditions of use | No protective measures required |
| Class 1M | Safe with the naked eye, but dangerous when using optical aids (e.g. B. Magnifying glass) | Avoid optical instruments |
| Class 2 | Visible radiation (400-700 nm), briefly harmless (blinking reflex protects) | Do not deliberately look into the beam |
| Class 2M | Like class 2, but with additional risk with optical aids | Do not use optical aids |
| Class 3R | Limited risk, direct gaze potentially dangerous | Caution, Do not allow direct irradiation |
| Class 3B | Dangerous with direct radiation | Protective measures mandatory |
| Class 4 | Highly dangerous (direct & diffuse), fire and explosion risk | Only use with comprehensive protective measures |
Only products up to class 2 are generally used for industrial warning systems. Higher classes would be unsuitable for applications without structural protective measures or would require approval.
What criteria are used to classify lasers?
Lasers are classified according to the international standard DIN EN 60825-1. The focus is not solely on power, but on a comprehensive risk assessment. Five factors are particularly important for the classification of lasers:
- Firstly, the output power plays a central role – i.e. how much energy is emitted per unit of time. The higher the power (measured in milliwatts), the greater the potential risk.
- Secondly, the wavelength is relevant: Only visible radiation between 400 and 700 nanometers allows natural protection through the blink reflex. Invisible infrared or UV radiation, on the other hand, can be dangerous without the eye reacting.
- Thirdly, the duration of exposure is taken into account. Short pulses may be less critical than continuous exposure at the same power.
- Fourthly, the beam geometry plays a role – a highly focused beam has a significantly higher energy density than a widely scattered beam.
- Finally, the standard also evaluates the possible use of optical aids such as magnifying glasses or cameras. Class 1M or 2M laser sources, for example, are harmless when viewed directly with the naked eye, but can cause damage when viewed under magnification.
Laser class vs. photobiological safety
LED warning lights are tested in accordance with EN 62471, which assesses so-called photobiological safety. This concerns hazards caused by UV, visible or infrared light. For laser sources, on the other hand, only the classification according to EN 60825-1 applies, as they generate bundled, coherent radiation.
A laser product cannot therefore be photobiologically tested and laser classified at the same time; the regulations are different.
Safety requirements and information
- Labeling requirements:
All laser products must be labeled with an appropriate laser class, including warning symbols and manufacturer information. - Installation & alignment:
Lasers must not be installed in such a way that people can unintentionally look directly into the beam. - Visibility vs. safety:
Class 1 or 2 systems offer high visual perceptibility without significant risk. - Training & documentation:
User awareness is crucial, especially when using Class 2 lasers. Unintentional exposure is rarely dangerous, but easily avoidable through sensitization.
FAQ: Laser classes for warning systems
What is laser class 1?
Class 1 lasers are considered safe under normal operating conditions. The accessible laser radiation is below the maximum permissible irradiation values (MZB) and poses no danger to eyes or skin.
What does laser class 1M mean?
Class 1M lasers are not dangerous when viewed directly with the naked eye. However, the use of optical instruments such as magnifying glasses or binoculars can increase the risk as they focus the radiation.
What characterizes laser class 2?
Class 2 lasers emit visible light in the range from 400 to 700 nm. Short-term exposure (up to 0.25 seconds) is considered safe for the eye due to the natural blink reflex.
What is the difference between class 2 and 2M?
Class 2M lasers are similar to class 2, but the use of optical instruments can increase the risk. Without such aids, they are also classified as safe for short-term exposure.
What does laser class 3R mean?
Class 3R lasers can be dangerous to the eye, especially when viewed directly. The accessible radiation exceeds the MZB values for the eye, but remains below the values for class 3B.
What are the dangers of class 3B lasers?
Class 3B lasers are dangerous to the eye and can also damage the skin when directly irradiated. Diffuse scattered radiation, however, is considered harmless.
What must be observed with laser class 4?
Class 4 lasers pose a high risk to eyes and skin. Even diffuse reflections can be harmful. There is also a risk of fire or explosion.