Classification of lasers indicates power rating
Largely simplified, lasers are bundled, focused and very intensive light. Depending on their power rating, they are divided into laser classes and furnished with the appropriate warnings, because: From a certain class, only certified experts may operate the laser and: So-called laser commissioners must certify the device and/or the machine.
A laser is classified, for example, according to EN 60825-1. The hazard potential of a laser depends on the thickness of its enclosure. Lasers of class 1, for example, are considered harmless for eye and skin.
A class 2 laser develops a light intensity in the visible spectral range, that is, it is harmless for eyes and skin for very brief radiation periods. Class 3 and 4 lasers, on the other hand, are quite hazardous for humans.
The following applies in principal: Lasers must never be directed to persons, regardless of the class of the respective laser. By the way: Already the lasers of a DVD burner belong to class 3 and are therefore quite dangerous for persons.