Understanding Laser Safety: Essential Knowledge for Laser Protection

Harmful Lasers Classifications

Lasers are classified based on their potential harm to human eyes and skin. Industrial high-power lasers emitting invisible radiation (including semiconductor lasers and CO2 lasers) pose significant risks. Safety standards categorize all laser systems, with fiber laser outputs often rated as Class 4, indicating the highest risk level. In the following content, we will discuss the laser safety classifications from Class 1 to Class 4.

Class 1 Laser Product

A Class 1 laser is considered safe for everyone to use and look at in normal situations. This means you won't get hurt by looking at such a laser directly or through common magnifying tools like telescopes or microscopes. The safety standards check this by using specific rules about how big the laser light spot is and how far away you should be to look at it safely. But, it's important to know that some Class 1 lasers might still be dangerous if you look at them through very powerful magnifying glasses because these can gather more laser light than usual. Sometimes, products like CD or DVD players are marked as Class 1 because they have a stronger laser inside, but it's made in a way that none of the harmful light can get out during regular use.

Our Class 1 Laser: Erbium Doped Glass Laser, L1535 Rangefinder Module

Class 1M Laser Product

A Class 1M laser is generally safe and won't harm your eyes under normal use, which means you can use it without special protection. However, this changes if you use tools like microscopes or telescopes to look at the laser. These tools can focus the laser beam and make it stronger than what's considered safe. Class 1M lasers have beams that are either very wide or spread out. Normally, the light from these lasers doesn't go beyond safe levels when it enters your eye directly. But if you use magnifying optics, they can gather more light into your eye, potentially creating a risk. So, while a Class 1M laser's direct light is safe, using it with certain optics can make it dangerous, similar to the higher-risk Class 3B lasers.

Class 2 Laser Product

A Class 2 laser is safe for use because it operates in a way that if someone accidentally looks into the laser, their natural reaction to blink or look away from bright lights will protect them. This protection mechanism works for exposures up to 0.25 seconds. These lasers are only in the visible spectrum, which is between 400 and 700 nanometers in wavelength. They have a power limit of 1 milliwatt (mW) if they emit light continuously. They can be more powerful if they emit light for less than 0.25 seconds at a time or if their light isn't focused. However, deliberately avoiding blinking or looking away from the laser can result in eye damage. Tools like some laser pointers and distance measuring devices use Class 2 lasers.

Class 2M Laser Product

A Class 2M laser is generally considered safe for your eyes because of your natural blink reflex, which helps you avoid looking at bright lights for too long. This kind of laser, similar to Class 1M, emits light that is either very wide or spreads out quickly, limiting the amount of laser light that enters the eye through the pupil to safe levels, according to Class 2 standards. However, this safety only applies if you're not using any optical devices like magnifying glasses or telescopes to view the laser. If you do use such instruments, they can focus the laser light and potentially increase the risk to your eyes.

Class 3R Laser Product

A Class 3R laser requires careful handling because while it's relatively safe, looking directly into the beam can be risky. This type of laser can emit more light than is considered completely safe, but the chance of injury is still considered low if you're cautious. For lasers that you can see (in the visible light spectrum), Class 3R lasers are limited to a maximum power output of 5 milliwatts (mW). There are different safety limits for lasers of other wavelengths and for pulsed lasers, which might allow higher outputs under specific conditions. The key to using a Class 3R laser safely is to avoid directly viewing the beam and to follow any safety instructions provided.

Class 3B Laser Product

A Class 3B laser can be dangerous if it directly hits the eye, but if the laser light bounces off rough surfaces like paper, it's not harmful. For continuous beam lasers that operate in a certain range (from 315 nanometers up to the far infrared), the maximum allowed power is half a watt (0.5 W). For lasers that pulse on and off in the visible light range (400 to 700 nanometers), they shouldn't exceed 30 millijoules (mJ) per pulse. Different rules exist for lasers of other types and for very short pulses. When using a Class 3B laser, you usually need to wear protective glasses to keep your eyes safe. These lasers also have to have a key switch and a safety lock to prevent accidental use. Even though Class 3B lasers are found in devices like CD and DVD writers, these devices are considered Class 1 because the laser is contained inside and can't escape.

Class 4 Laser Product

Class 4 lasers are the most powerful and dangerous type. They are stronger than Class 3B lasers and can cause serious harm like burning skin or causing permanent eye damage from any exposure to the beam, whether direct, reflected, or scattered. These lasers can even start fires if they hit something flammable. Because of these risks, Class 4 lasers require strict safety features, including a key switch and a safety lock. They are commonly used in industrial, scientific, military, and medical settings. For medical lasers, it's crucial to be aware of safety distances and areas to avoid eye hazards. Extra precautions are needed to manage and control the beam to prevent accidents.