Laser is a special light source. Its radiation has little impact on human body. Its main hazards are eyes and burns.

International classification of lasers:

This classification is an international standard classification, which has passed a consistent classification recognized by the scientific community all over the world. This is convenient for unifying the safety level of laser equipment and national trade. The classification is divided into four levels: Level I, Level II, Level III, and Level IV.

The higher the classification level, the greater the risk. The laser grade must be marked on the laser system with Roman numerals. All regular laser products are generally labeled with classification labels. In addition to graphic and text warnings, the labels also contain the following information: wavelength, total output power, and laser classification.

The following is the description of Class IV laser:

1. Safety level: Level I. Laser power: less than 0.5 milliwatt, safe laser. Class I laser will not cause harm to human health under normal use conditions, but this type of product must also be designed to prevent workers from entering the laser radiation area during the work process.

2. Safety level: Level II. Laser power: 1 milliwatt. This class of laser has low power and visible laser. Humans can protect themselves by blinking and reflecting strong light with their eyes, but if they look directly for too long, it will bring danger. Warning signs need to be posted at the laser outlet for Class II laser.

3. Safety level: Level III. The third level is divided into 3a and 3b,

Class 3a laser, laser power: 1mW to 5mW, Class 3a laser is the same as Class II laser, and warning signs need to be posted at the laser outlet. The human eye only sees for a short time, and the human eye will play a protective role in light protection and reflection. However, if the light spot enters the human eye when it is focused, it will cause damage to the human eye.

Class 3b laser, laser power: 5 milliwatts to 500 milliwatts, which may cause injury if viewed directly or diffusely. Class 3b lasers are generally labeled with the "Danger" sign. Although they are harmful to the eyes, if the light spot is not focused, there is a small risk of fire or skin burns. However, it is recommended to wear eye protection when using this level of laser.

4. Safety grade: Grade IV. Laser power: above 500mW, this level of laser will cause great damage to eyes and skin, and direct reflection and diffuse reflection will cause damage. All Class IV laser equipment must carry the "Danger" sign. Class IV laser can also damage the materials near the laser and ignite combustible substances. When using this class of laser, it is the same as Class 3b laser.