Three Unexpected Dangers of Working with Lasers
Lasers are dangerous, and most people know better than to stare directly into a beam of light. But that’s not the only risk of working with lasers in scientific, industrial, or military settings. Sometimes the light is redirected outside of your control, and other times lasers can be used against you to cause temporary vision problems. Here are three unexpected dangers of lasers and how you can protect yourself and your employees against them.
1. How can you protect against laser strikes?
Pilots can be startled or temporarily blinded by even short exposure to flashes of laser light. Even handheld lasers can cause flash blindness from a long-distance away. While the risk of an incident is relatively low, flash blindness can be extremely, especially at key moments of operating equipment. The FAA has been collecting standardized data on the number of laser strike incidents since 2005, and the number has steadily been climbing through the thousands of annual incidents.
While local, state, and federal governments have been making the penalties for flashing lasers at an aircraft more severe, the risk of laser strikes is still too high. According to the FAA, the increasing statistics may just be due to increased pilot awareness and the easier process for reporting. However, the problem is also the growing availability of green handheld lasers, which are far more visible and impactful. The risk of laser strikes is even greater in military settings.
Many piloting SOPs are starting to include guidelines about wearing laser strike safety eyewear during low flight times and while an aircraft is taking off and descending. Look for lenses that protect against green laser light, which is the most common and most dangerous visible laser beam.
2. Visible, ultraviolet, and infrared light’s energy absorption will damage ocular cells, even without direct viewing.
Lasers can produce heat. When the laser’s light is in the visible spectrum, the retina absorbs the energy. This energy can damage or destroy cells in the retina, which is sensitive to even minor degrees of damage. When the laser is outside of the visible light spectrum, such as infrared or ultraviolet light, that damaging energy is instead concentrated in the cornea and lens. The energy that is concentrated in the retinas can hurt photoreceptor cells nearly instantaneously, whereas corneal and lens damage can increase the risk of cataract development. If the lasers operate outside of the visible light spectrum, they won’t trigger a protective blink reflex and many people won’t notice the risk until some damage has already occurred.
Last safety glasses block the absorption of that light and energy. While the glasses’ primary goal is to protect the eyes themselves, bigger lenses also protect the sensitive skin around the eyes. Bigger lenses also protect the eyes from diffuse light and angled reflections rather than protecting against direct laser light transmissions.
Even light that is transmitted through clear substances with little to no reflection can be dangerous. Some window coverings have additional layers of protection that try to limit diffusion and keep laser beams contained within a small area of work. While these safety measures can help protect people adjacent to an ongoing task, they are no substitute for direct protective eyewear.
3. Laser beam reflections can hurt observers’ eyes.
Controlled environments are designed to control laser reflection and to minimize any dangers of redirected laser radiation. However, even laboratories could have unexpected hazards that reflect the light back towards your employees or any observers. In the military, the environments in which lasers are being used are far less controlled. Lasers can reflect off of any surface, even atmospheric particulates. This is why, even when there is little chance of people crossing the laser’s initial path, you need protective eyewear. Once the beam of light is reflected back, it’s hard to fully control or redirect the light. Safety glasses keep the radiation away from people’s eyes with minimal reduction in their field of view. The two main types of radiation are direct and diffused reflection.
When can direct, or specular, reflection occur?
Specular reflection happens when the concentrated beam of light bounces off a smooth surface. There is little to no loss in intensity, and the power of the laser is just as concentrated as before. This can happen when the laser strikes glass, a calm body of water, or smooth metal. Specular reflection bounces the light back at the angle of impact, like a mirror.
Even curved surfaces can produce a specular reflection. While it is far more common for a curved material to diffuse, or scatter, the laser light, striking a manmade, concave surface at the right angle can concentrate the laser and make its reflection even more dangerous. This doesn’t happen often, but it can be a concern in unprotected testing environments and during military action in urban or industrial areas.
Is diffuse reflection dangerous?
Most laser reflections are diffuse. When the beam of light reflects off of a rough surface, the single beam of light is divided and scattered. While that means each individual beam of redirected light is less concentrated, the effect is much less predictable. Sometimes, the laser light is safe enough to view unprotected. With a Class IV laser system, it can still hurt the observer’s eyes and cause short- to long-term vision impairment.
Even diffuse laser light can be made more dangerous when using an optical aid. Binoculars and scopes increase the beam’s intensity and direct the focus right at the user’s eyes. Protective eyewear that can be used in conjunction with optical aids and viewing equipment is absolutely essential. This is even more essential in environments with lasers outside of the visible light spectrum. Without a cue to trigger a blink reflex or telling the observer to look away, the laser might be intensified until the damage is caused without warning.
Direct intra-beam laser light isn’t the only danger to your eyes and skin. Any time there is a risk of uncontrolled laser beams and reflection, you need to have measures in place that protect the surrounding observers. Make wearing safety glasses part of your regular safety procedures. Go to Philips Safety Products here to find a wide selection of protective eyewear. You can choose the right safety equipment based on the types of lasers in use, the environment, and the hazardous conditions you want to mitigate.