Flash -- Sizzle -- Dark Spot
January 31, 2012
Soldiers injured in laser incidents often report seeing a flash, while others hear a short sizzle and then see a dark spot. Symptoms include temporary blindness, blurred vision and headaches. Fortunately, these types of injuries are preventable if Soldiers receive the proper training and apply what they learn to laser operations.
Between fiscal 2009 and 2010, the U.S. Army Combat Readiness/Safety Center received 16 accident reports on eye injuries caused by lasers. It's easy to see how these accidents could happen, especially if Soldiers haven't been provided proper training. Many of these lasing incidents occurred as convoys or patrols approached traffic checkpoints and security towers controlling the gates at forward operating bases. We've even had an incident where two Soldiers were playing around with a laser that resulted in an eye injury to another Soldier.
As the Army continues to use lasers in the field, the potential for accidental lasing of Soldiers exists. However, it is possible to reduce these incidents through education. Knowing the difference between the classes of lasers and how to handle each of them safely are key elements in reducing lasing accidents.
All laser systems must have a warning label that identifies the class of the laser. These labels may be found on a wide range of items such as personal CD and DVD players to Army equipment, including rangefinders and target designators used by Soldiers. The chart below provides the different classes of lasers and the hazards, if any, with each class:
Laser Classification Meaning
Class 1 or I "Eye Safe"
Class 2 or II No hazard for exposures of less than 0.25 s to visible lasers
Class 3A or IIIa Not a hazard under normal viewing conditions
Class 3B or IIIb Direct Viewing Hazard
Class 4 or IV Direct Viewing Hazard and possibly a diffuse viewing hazard, and/or fire hazard.
In 2007, the American National Standards Institute re-designated the laser classifications and the below chart reflects those changes. Army equipment will fall under either of these charts, depending when the equipment was manufactured. For classification clarification, contact your unit or organization's radiation safety officer.
Laser Classification Meaning
Class 1 Lasers emit at levels that are not hazardous under any viewing or maintenance conditions. They are exempt from control measures. (However, as a matter of good safety practice, avoid intra beam viewing.)
Class 1M Lasers emit at levels that are not hazardous under normal viewing conditions, but could be a hazard for intra beam viewing through magnifying optics. They require control measures to prevent intra beam viewing with magnifying optics within the reported hazard distance, and a "caution" label. The laser output cannot exceed the Class 3B accessible emission limits for optically aided viewing.
Class 2 Lasers emit in the visible portion of the electromagnetic spectrum and are a potential eye hazard only for prolonged intra beam viewing. The aversion response, including the blink reflex, would normally prevent over exposure by limiting the exposure to 0.25 s or less.
Class 2M Lasers emit in the visible portion of the electromagnetic spectrum and are a potential eye hazard only for prolonged intra beam viewing. The aversion response, including the blink reflex, would normally prevent over exposure by limiting the exposure to 0.25 s or less.
Class 3 Lasers emit in the infrared, visible, or ultraviolet portions of the electromagnetic spectrum and are a hazard for direct intra beam and specular reflection viewing. Diffuse reflections are not normally hazardous. These lasers require additional control measures to include a "danger" label.
Class 3R Lasers exceed the Class 1 or Class 2 accessible emission limits (AEL) by not more than 5 times.
Class 3B Lasers exceed the Class 1 and Class 2 AEL by more than 5 times, but emit less than Class 4 lasers.
Class 4 (High-power) lasers emit in the infrared, visible, or ultraviolet portions of the electromagnetic spectrum and are hazardous for direct intra beam exposure and some can produce a hazard from diffuse reflections. They may also produce fire, material damage, laser generated air contaminants and hazardous plasma radiation.
To prevent eye and skin injuries and protect vision, rigorously apply the following controls any time lasers are in use:
• Never point a laser at anyone's face.
• Know the class of laser you are using.
• Appoint a laser safety officer/NCO in all units using lasers.
• Train personnel on laser safety.
• Establish rules of engagement for laser operations.
• Ensure operators receive the proper training on the use of their specific laser systems.
• Properly secure lasers when not in use.
• Remove batteries when the laser is not in use.
• Do not remove warning labels from the laser.
• Never leave an operable laser unattended.
• Check the security of mounting hardware.
Lasers systems are a part of a Soldier's life on the battlefield and in training. Proper education is essential to Soldiers understanding the hazards of misusing these tools. The Army Surgeon General offers a simple tip that Soldiers and Leader's alike should pay attention to when it comes to preventing accidental laser injuries: "Always treat lasers with the same respect and care as you would a loaded weapon."
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Field Manual 8-50, Prevention and Medical Management of Laser Injuries, provides basic preventive, protective and diagnostic information on laser injuries. For additional information and resources regarding laser safety, visit the United States Army Public Health Command's Laser and Optical Radiation site at http://phc.amedd.army.mil.
Did you know laser dazzlers started out somewhat simply as a form of nonlethal crowd control and tactical area denial? The concept was to scan a laser quickly over a crowd, using a low-powered beam to "dazzle" the people into temporary blindness. Unlike other types of laser weapons, the beam would not be tightly focused, in order to hit as large an area as practical, but would still have enough energy density to burn enough of the retina to cause vision loss. Today, the military uses Green Laser Dazzlers (nonlethal laser weapons). The effective range of this high-powered laser can reach between 20 to 300 meters away when necessary. Designed to cause disorientation, this dazzler lasts for about 15 minutes. The whole retina becomes bleached with a green light, similar to a bright camera flash. They have been an indispensable tool for Soldiers and military bases.
Check out our new Laser safety video by visiting https://safety.army.mil/multimedia or by scanning (insert QR code) with your smart phone.