Lasers are divided into four safety levels. Different levels cause different harm to the human body, and the protection standards for lasers are also different.

1. Security level: level one.

Laser power: less than 0.5 milliwatts, safe laser, first-class laser will not harm human health under normal conditions of use, but this kind of product still needs to ensure that it is used to prevent workers from entering the laser radiation area during work design.

2. Security level: Level two.

Laser power: 1 milliwatt. This level of laser has low-power, visible laser. Humans can protect themselves by blinking and reflecting the strong light, but looking directly for too long will bring danger. The second-level laser must be at the laser exit port Warning signs are partially posted.

3. Security level: level three.

The third level is divided into two types, 3a and 3b. The 3a laser has a laser power of 1 mW to 5 mW. The 3a laser is the same as the second, and a warning sign must be posted at the laser light exit. If it is only seen for a short time, the human eye will have a certain protective effect on the protective reflection of light, but 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 mW. Up to 500 milliwatts, it may cause injury if viewed directly or diffusely reflected. Class 3b lasers are generally affixed with "danger" signs. Although they are harmful to the eyes, there is less risk of fire or skin burns if the light spot is not focused. However, it is recommended to wear eye protection when using this class of lasers.

4. Security level: level four.

Laser power: 500 milliwatts or more, this level of laser has great damage to the eyes and skin, direct reflection and diffuse reflection can cause damage. All Class 4 laser equipment must bear the "Danger" sign. Level 4 laser can also damage materials near the laser and ignite flammable materials. When using this level of laser, you also need to wear eye protection as with 3b.