Laser Safety for Laboratory Researchers, Technicians, and Students
Given it’s the most vulnerable part of the body, it’s not surprising that the eye is often injured in laser accidents. Because it’s an optical organ, it’s particularly susceptible to lasers in the visible and near-infrared spectrum. Laser beams of this type readily travel through the cornea and lens and reach the light-sensing cells of the retina. The eye’s lens focuses the laser beam on a small area of the retina, which can intensify the laser energy by a factor of 100,000. This damages the retina and causes permanent loss of a portion of one’s central vision. Other laser wavelengths can damage and cause scarring to the cornea or accelerate the onset of cataracts on the lens of the eye.
Despite decades of experience with lasers and the establishment of safety protocols covering most work situations, laser accidents continue to happen. The reason often comes down to negligence.
Another reason is that unlike many industrial settings, which are fixed environments, the equipment arrangements of laboratories change frequently. New laser arrangements require optical alignment, which is when most laser accidents occur. Just when workers become familiar with, and can safely work with one arrangement, it is taken down and replaced by another with a new set of potential hazards. Safety in such a changing environment can never be taken for granted.
Enhance the safety of your lab workers by following these tips:
Wear Laser Safety Glasses
Laser safety glasses are your last line of defense. Regardless of the mistakes made by yourself or others, laser-induced eye injury won’t happen if everyone is wearing protective eyewear. However, ensuring that everyone uses them is not always easy. People can have lapses regarding eye safety for a number of reasons. These include:
- When wearing safety glasses is inconvenient. If a worker intends to do laser work for a very brief time, he may reason that it’s not worth the bother of going out of his way to find a suitable pair of laser safety glasses. However, it only takes one slip-up for an accident to occur.
- Having false assumptions about safety. For example, after someone completes an alignment of the laser setup (a potentially hazardous task), she may assume the arrangement is safe. However, she may have forgotten to do a complete check for stray laser reflections from mirrors and other components along the beam’s path. This kind of oversight has caused eye injuries in the past.
- Removing safety glasses because of discomfort. Poor-fitting glasses can cause discomfort or even pain. Removing the eyewear for even a brief moment risks an eye injury. Discomfort also causes distraction. Work safely and comfortably by getting laser safety glasses with a proper fit.
- Complacency. Years of experience or familiarity with a routine makes people too comfortable in potentially hazardous situations. Experience or familiarity doesn’t guaranty that the person or coworkers won’t make mistakes.
In addition to wearing protective eyewear 100% of the time when the laser is in use, all workers must wear the correct eyewear. This means that only safety glasses meant for your laser’s wavelength and power output are to be used. If a new lab setup is using a different laser from the previous experiment, the previously used safety glasses my not be appropriate. When tunable lasers are used, multi-wavelength safety glasses work best.
Make sure that all workers are using the right protective eyewear for the current setup. The glasses must be undamaged (both frames and lenses) with no scratches. They must fit comfortably, provide both frontal and side protection, and have the proper fit. Glasses prone to slippage or falling off are unreliable and dangerous. If the glasses have loose connections or are discolored, immediately replace them. There are no acceptable substitutes for laser safety glasses.
Other Safety Tips
- Class 3B and Class 4 laser beam alignment should only be done by trained and experienced workers.
- Always follow safety protocols when engaged in laser beam alignment.
- Use a weak visible laser in lieu of a class 3B, class 4, or invisible laser when doing the alignment. Otherwise, use the lowest power setting.
- Enclose the beam path when feasible. Full beam enclosure is preferable to partial beam enclosure, which in turn, is preferable to an open beam arrangement.
- The height of the beam path should never be at eye level.
- A direct view of the laser setup by people not involved with the test/experiment should never be possible. That is, non-participants should never have access to the test area when the laser is in use nor should they be able to view the test through a window, doorway, or from across the room. In addition, they should be safe from stray reflected beams.
- Terminate laser beams leaving the optics with beam blocks.
- Educate all workers about the properties of the laser used. For example, they should be knowledgeable of its specific hazards such as the beam’s visibility or invisibility.
- Methodically track down and block all stray beam reflections.
- Always keep the work area free of clutter. Unneeded objects can potentially reflect the laser beam in an unanticipated direction.
- All operations with class 3B and class 4 lasers must be done under the oversight of a qualified laser safety officer (LSO). The LSO ensures that workers adhere to all safety regulations.
Finally, do everything you can to instill a culture of safety in your laboratory. This starts with hiring quality workers who prioritize lab safety. If you aren’t sure of which laser safety glasses to get, or have questions about any of our large selection of products, our experts will gladly help you. For more information or technical assistance, don’t hesitate to contact us.