Four main hazards of high-power lasers and their protection methods

Although lasers have existed for decades, it seems that it is difficult for industry experts who study lasers to obtain public laser safety knowledge, and there are insufficient understandings about the hazards of high-power lasers. The great danger often comes from a lack of awareness. Without understanding, users and workers of high-power lasers may not know what dangers they face when they are in danger.

As a laser practitioner, if you don’t know this knowledge, it is really dangerous.

Today, I will talk to you about the 4 main hazards and protection methods of high-power lasers (I will call lasers capable of outputting 1KW and above as high-power lasers).

Hazard 1: Burns and blindness

The most obvious hazard of laser is the possibility of blindness. Even if the wavelength of the laser used exceeds the sensitive range of the eyes (400-1400nm, visible light and near-infrared light), it may still cause damage to the eyes. Although there is no longer a need to worry about direct blindness from lasers outside the sensitive range, there are still many other ways to make eyes hurt by laser energy. Eye burns, distortion of the shape of the eyes, decreased vision, boiling of eye fluid, degeneration (attenuation) of the protein in the eyes leading to milky white blind spots and internal bleeding, etc., are all possible symptoms of direct laser injection into the eyes. Similarly, just because the beam is not visible light (400-700nm) or near-infrared light (700-1400nm), it cannot prevent instantaneous damage and blindness. If the energy output of the laser is high enough, it may still cause immediate burns, just like touching a hot stove.

Direct exposure to laser light is the most dangerous situation, but not the only danger. In addition, for direct exposure to laser light, depending on the situation, indirect exposure of the reflected beam may also be dangerous. There are two types of reflection: specular reflection (the beam is reflected from a smooth surface or partially reflected or through glass, where the beam continues on its new path) and diffuse reflection (the light is scattered from a rough surface (such as glass) in all directions) Light). When the beam is reflected, some energy will be partially dispersed, but if the laser has enough initial energy, the reflected beam is still dangerous.

Since the reflected beam is still coherent with the laser, it should be treated the same as the beam directly from the laser source. Diffuse lasers are usually dispersed enough to make them harmless, but the diffused light from Class 4 lasers has enough energy and is irritating to the eyes. If the eyes are not properly protected, the vision will be reduced over time. decline.

Laser protective glasses

The best practice to control the laser beam so that it does not affect people who are not involved in this process is to place and use the laser only in a closed room. If possible, it is best to have a completely enclosed and well-ventilated work space.

Hazard 2: chemical hazard

This hazard is similar to the hazard of welding and requires high-temperature work safety regulations-many industrial lasers are used for cutting, etching, and ablation (such as grinding or grinding) to burn off materials. This makes high-power lasers the same hazards as many high-temperature operations such as welding. According to the law of conservation of mass, the burned material will not disappear and disillusion. Some of these burning substances will exist in the air as toxic gases. Lasers burn metals and other solid materials as well as oils, solvents, and other chemical substances to produce toxic exhaust gas. When exposed to the concentrated energy of the laser, these substances burn and merge into the air or evaporate into the air.

In order to prevent the inhalation of these toxic gases, the laser work at high temperature requires ventilation. Although air circulation throughout the work area helps, this method only dilutes the exhaust gas. Local exhaust ventilation is the best way to place a straw next to the laser to inhale, and it is the best way to effectively control a large amount of exhaust gas. For example, the products of Dongguan Cooper Electronic Equipment Co., Ltd. provide such solutions.

Hazard 3: Dangerous energy sources other than laser

High-power lasers have a lot of current through their internal mechanisms. Therefore, all covers must be installed in place to prevent electric shock caused by live wires or other electrical contacts. In addition, because there is a risk of injury or death when working on such machines, it is important to perform and follow the lockout [LOTO] procedure when performing maintenance. Although electrical safety and LOTO cover a lot of content and cannot be described in depth here, these should be kept in mind when using high-power lasers.

Hazard 4: Damage to personal protective equipment

The correct choice of laser protective glasses can prevent or significantly reduce laser damage. However, when the laser power output reaches the kW level or higher, the energy from the laser will melt the safety glasses, especially for some low-quality laser safety glasses. Therefore, when using high-power lasers, it is important to consider the settings of the laser to reduce the risk of direct exposure to the beam. Personal protective equipment is very important to protect safety performance, but when using high-power lasers, safety gears may provide a false sense of security. When using these high-power lasers, safety equipment cannot guarantee protection.

Safeguard

When considering how to prevent laser damage, please focus on the safest solution first. The following editor provides a few suggestions to protect security:

1. Avoid risks

Can the work flow be completed without using a laser? Is it feasible to use a lower power laser? Is the replacement process more or less dangerous than using a laser? Without powerful risk assessment tools, this can be difficult to judge, because alternative processes often have different types of hazards.

2. Isolation

Can the laser be used in a certain way so that no one is exposed to the high-energy laser? For example: In a closed room, use automatic process or remote control through camera feed, and turn off the laser through the interlocking device on the door. Turn off the laser when someone enters by mistake?

3. Engineering control

Is it possible to prevent dangerous lasers from injuring workers, laser users, or passers-by through interlocking devices, barriers, or other physical controls? And such physical control methods must be useful, even if workers are distracted, they can effectively provide safety protection.

4. Administration

Some administrative measures can be used to strengthen management, such as delimiting strict safe working areas and strictly observing safety distances, etc., to implement these best work practices to prevent injuries? But it has to be said that administrative control is a weak supplement to security, because they require attention and compliance to be effective. Non-compliance or brief wandering may destroy the security provided by administrative control.

5. Personal protective equipment

Safety equipment, such as laser safety glasses, can be used to reduce injuries, but this does not provide adequate safety protection. The safety gear has the worst effect because it cannot prevent injury (only reduces the impact). In addition, as mentioned earlier, the extremely high energy output of certain high-power lasers can melt the laser safety glasses, thereby rendering personal protective equipment ineffective.