When Do You Need To Wear Laser Safety Glasses While Operating A Laser Marking Machine?

With the widespread application of laser technology in various fields, laser marking machines are widely used in industries such as metal processing, electronics, medical devices, and packaging. Their precision and efficiency make them ideal for engraving, etching, and marking various materials. However, the high-intensity laser beams they emit pose a significant risk to our eyes. Wearing laser safety glasses is not just an optional precaution, but a crucial safety measure. So, when exactly is it necessary to wear laser safety glasses when operating a laser marking machine?

1. When operating open or semi-open laser marking machines

If the laser marking machine is not fully enclosed, operators will be exposed to:

Direct laser beams

Reflected laser radiation

Scattered laser light

In these cases, even if the laser beam is invisible (e.g., fiber laser or infrared laser), laser safety glasses must be worn.

Main risk: Reflected beams can cause serious and irreversible eye damage within milliseconds.

2. When performing manual adjustments, focusing, or debugging

Laser marking machines typically require:

Manual focusing

Parameter adjustments

Alignment or calibration

Test marking

During these steps, protective covers or shields may be removed, increasing the risk of exposure. Therefore, laser safety glasses must be worn during all setup and debugging operations, even if the marking time is short.

3. When using high-power or Class 3B/4 lasers

Most industrial laser marking machines belong to: Class IIIB or Class 4 lasers. Class IIIB lasers have a power of 5-500mW, and direct observation within the beam is very dangerous; scattered beams may also be dangerous at close range. Class 4 lasers have an output power greater than 500mW, higher than Class IIIB lasers, and pose a fire hazard.  Besides direct light, diffused and reflected light are also dangerous.

These laser classes can cause permanent eye damage from direct or reflected exposure.

According to international laser safety standards:

Eye protection devices, such as laser safety glasses, are required for Class IIIB and Class 4 lasers.

4. When marking highly reflective materials

Materials such as stainless steel, aluminum, copper, and polished metals reflect laser energy in unpredictable ways. Even diffuse reflections can exceed the maximum permissible exposure (MPE) for the human eye. Therefore, in these situations, wearing laser safety glasses is strongly recommended, even if the machine is partially shielded.

5. During maintenance, cleaning, or troubleshooting

Maintenance work may include:

Opening the laser housing

Removing protective panels

Testing laser output

These situations significantly increase the risk of accidental exposure.

All maintenance personnel (not just operators) need to wear laser safety glasses.

6. When safety interlocks or guards are disabled

In some production environments, the following may be temporarily disabled:

Safety interlock systems

Protective doors

Light shields

Once the safety system is bypassed, laser safety glasses become the last line of defense and must be worn.

7. When required by safety standards and regulations

International and national laser safety standards, such as:

ANSI Z136 (USA)

EN 207 / EN 208 (Europe)

GB 30863 (China)

Clearly stipulate that appropriate laser safety glasses must be used whenever there is a risk of eye exposure to harmful laser radiation.

8. How to choose the right laser safety glasses for laser marking machines

① Correct wavelength range: Safety glasses are designed to block specific laser wavelengths, meaning the protection range of the laser safety glasses must cover the actual laser wavelength used. For example, if the UV laser marking machine operates at a wavelength of 355nm, you need to choose laser safety glasses that can protect against 355nm, such as LP-GHP laser safety glasses from LaserPair.

② Choose the appropriate optical density (OD value) based on laser power: Optical density (OD value) refers to the attenuation ability of the laser safety glasses to the laser. The higher the OD value, the stronger the attenuation ability. If the laser marking machine has higher power, you need to choose laser safety glasses with a higher OD value.

③ Compliant with certification standards (compliant with ANSI / EN / GB standards)

Conclusion

When are laser safety glasses needed? You need to wear laser safety glasses if any of the following conditions apply while operating a laser marking machine:

The system is in an open or semi-open state.

You are performing adjustments, focusing, or calibration.

The laser is Class 3B or Class 4.

Reflective materials are being marked.

Maintenance or troubleshooting is being performed.

Safety interlocks are disabled.

In short: If there is any possibility of your eyes being exposed to laser radiation, you must wear laser safety glasses.