A laser’s class reveals essential information about its power, radiation and the potential risks associated with its use. From class 1, considered without danger, to class 4, which can cause eye damage, each type of laser requires appropriate safety measures. Class 3B and 4 lasers in particular are considered dangerous to the eyes. Understanding these classifications is essential to the safe and effective use of lasers.
Understanding the different types of lasers
To better understand the different types of lasers, we can classify them into several categories according to their active environment. This determines the laser’s characteristics, notably its wavelength
- Gas lasers use gaseous compounds to amplify light, such as helium-neon (HeNe) or CO2.
- Solid-state lasers are based on solid materials, such as ruby or Nd:YAG.
- Fiber lasers use optical fibers as the amplifying environment.
- Semiconductor lasers, or laser diodes, exploit the properties of certain semiconductor materials.
- Liquid lasers, or dye lasers, use organic dyes dissolved in a solvent as the active environment.
Each of these types has specific characteristics and applications (lighting, communication, surgery, marking, cutting, welding, etc.).
Decoding laser classes: 1 to 4
To fully understand laser classes, we need to refer to international norms, such as IEC 60825-1-2014 Ed.3.0.
Class 1 includes lasers that are safe during use, even when viewed directly into the beam over a long period of time. This includes high-power lasers confined in such a way that no radiation can escape.
Class 2 covers visible radiation lasers (400 to 700 nm wavelength, and power less than or equal to 1 mW).
Class 3 lasers are of medium power (less than 5 mW) and can be dangerous in the event of persistent direct vision
Finally, class 4 lasers are high-powered (over 500 mW) and are generally used in medical surgery, laser cutting, welding and micromachining. These lasers can cause serious eye and skin injuries, and also present a fire hazard.
Specific features of laser class 3B
Laser class 3B covers lasers capable of emitting an output power of up to 500 mW. They are considered dangerous if exposed to the beam directly through the eyes.
- Risks: Class 3B lasers can cause irreversible eye damage in the event of direct contact with the beam. However, viewing diffuse reflections is generally safe.
- Safety: The use of these lasers requires specific safety measures. Protective eyewear is highly recommended. In addition, the operator must be trained in laser safety to minimize risks.
- Applications : Class 3B lasers are commonly used in various scientific, medical and industrial fields. For example, they are used in dermatology for wrinkle reduction and in ophthalmology for certain surgical procedures.
It is essential to follow safety instructions to avoid any risk of direct exposure to the beam.
Class 1 laser equipment: safe for the eyes?
Class 1 laser equipment is considered safe under normal conditions of use. Its power is very low, or it is covered by a protective casing that blocks the laser radiation. This means that, even if you look directly into the beam over a long period of time, there is no risk to your eyes.
However, this does not mean that certain precautions should not be taken. For example, it is recommended not to use optical instruments such as binoculars or telescopes to observe the beam, as this could increase the power of the radiation and therefore the risk to the eyes.
In most cases, lasers in this category are totally enclosed, and direct access to the beam is not possible when laser engraving is launched.
In short, Class 1 laser equipment is generally safe for the eyes, but it is always necessary to handle such equipment with care and to observe safety instructions.
Class 4 laser safety goggles: are they necessary?
Exposure to class 4 lasers can cause irreversible damage to eyes and skin, as well as a fire risk. In this context, the wearing of protective eyewear becomes an unavoidable necessity to guarantee the user’s safety.
Class 4 laser goggles are specially designed to block or attenuate the specific radiation emitted by these lasers. They are fitted with scratch-resistant mineral glass or polycarbonate filters.
- Filters must be chosen according to the specific wavelength of the laser used.
- Glasses frames must be adapted to the user’s morphology to guarantee optimum comfort.
It is highly recommended to choose protective eyewear that complies with European standards, in particular EN 207, for total eye protection against laser radiation.
Laser power: impact and safety measures
The power of a laser has a direct impact on its level of danger. High-power lasers, such as Class 4, can cause irreversible damage to eyes and skin, and even trigger fires. It is therefore crucial to take appropriate safety precautions when using them.
- Special protective eyewear must be used to attenuate radiation.
- It is also advisable to avoid direct exposure to the beam.
- High-power lasers should only be used by trained professionals, in appropriate and safe areas.
Manufacturers of laser equipment are required to provide clear information on the class and power of their products, as well as on precautions for use. By carefully following the various guides we offer on our site, you’ll easily know which laser engraver to choose according to your needs.