WHAT IS A CLASS 3B LASER?
Class 3B lasers are hazardous for eye exposure. They can heat skin and materials but are not considered a burn hazard. For visible-light lasers, Class 3B lasers’ output power is between 5 and 499 milliwatts. Class 3B Laser Pointer is the same as the Roman numeral “Class IIIb” you may see on some lasers’ labels.
A Class 3B laser can be a distraction, glare or flashblindness hazard for pilots and drivers. NEVER aim any laser towards an aircraft or vehicle that is in motion. Always be aware of the beam location. Keep it away from people’s eyes and heads. Watch out for reflected beams from glass and shiny surfaces. When outdoors, you must avoid aiming at or near aircraft.
SAFE USE GUIDANCE – GENERAL
Class 3B visible-beam lasers are medium powered, from 5 to 499 milliwatts. A Class iiib laser can cause eye injury. The more powerful the laser, the greater the chance of injury. Use of laser protective eyewear is suggested or recommended (depending on the laser’s power level), as discussed elsewhere on this page.
A Class IIIB laser can be a distraction, glare or flashblindness hazard for pilots and drivers. NEVER aim any laser towards an aircraft or vehicle that is in motion. Always be aware of the beam location. Keep it away from people’s eyes and heads. Watch out for reflected beams from glass and shiny surfaces. When outdoors, you must avoid aiming at or near aircraft.
This is not a toy. Children should not be permitted to use Class 3B lasers. Any teenager using a Class IIIB laser should be continuously supervised by a responsible adult. A number of teenagers have caused eye injuries to themselves or others by misusing Class 3B and Class 4 lasers.
Class 3B (and 4) lasers are too powerful to be used as pointers. Some Class 3B (and 4) laser pointers may look like pointers, but these should not be used for pointing. Use a Class 2 (less than 1 mW) or Class 3R (less than 5 mW) laser for pointing purposes.
EYE INJURY HAZARDS
Class 3B visible-light lasers are hazardous for eye exposure. They can cause burns to the retina. A person cannot turn away or blink fast enough to prevent retinal eye injury from a nearby Class 3B laser. At the low end, around 5 to 50 milliwatts, a Class 3B laser poses a moderate risk of eye injury. It is unlikely that a handheld beam aimed from more than a few dozen feet away would cause injury — laser light could not stay on one spot on the retina long enough for heat to build up to injurious levels. However, the risk is increased if the beam is held steady or if the laser is relatively close to the eye.
As the laser power increases, the risk of eye injury also increases. At the high end, around 250 to 500 milliwatts, even a brief exposure could cause retinal damage. Avoid all eye exposure to beams from Class IIIB lasers. This includes unintentional or accidental exposures — be careful to keep the beam away from eyes and faces.
Also, remember that reflections off mirrors, glass, and shiny surfaces can be just as hazardous as the direct beam. Avoid reflected Class 3B beams the same way you would avoid the direct beam. The Nominal Ocular Hazard Distance (NOHD) for a lower-powered 50 mW Class 3B visible-beam blue laser with a tight beam (0.5 milliradian divergence) is 330 ft (100 m). The Nominal Ocular Hazard Distance (NOHD) for the most powerful 499 mW Class 3B visible-beam laser with a tight beam is 1,050 ft (320 m).
If you are closer than the NOHD distance to the laser, there is a possibility of retinal damage if the direct or reflected beam enters your eye. The closer you are to the laser and the longer the beam is in the eye, the greater the chance of injury.
A Class 3B laser is not normally considered a skin or materials burn hazard. However, if the laser “dot” is kept motionless on skin at close range, heat can be felt. The more powerful the Class iiib laser, the sooner the heat will build up.
Do not deliberately attempt to burn skin. This can be very painful, can take long to heal, and can leave a permanent scar. If the laser “dot” is kept motionless on a material for a few seconds at close range, higher-powered Class 3B lasers can cause materials to smolder or burn. Dark materials which absorb heat, and lightweight materials such as paper and fabric, are most easily burned by visible laser beams.
AIRCRAFT AND VEHICLE SAFETY
NEVER aim any laser towards an aircraft or vehicle that is in motion. The bright light can flashblind, cause glare, or distract the pilot or driver.
The most powerful Class 3B laser beam (499 mW) can temporarily flashblind a pilot or driver, causing afterimages, within 1 mile (1.6 km) of the laser. It can cause glare, blocking a pilot or driver’s vision, within 4.4 miles (7.1 km) of the laser. It can cause distraction, being brighter than surrounding lights, within 44 miles (71 km) of the laser.
CLASS 3B SAFE USE GUIDANCE
Laser glasses or goggles are suggested for lower-powered Class iiib lasers, and are recommended for higher-powered Class 3Bs. They should be selected to protect against the laser’s power and wavelength. The eyewear should not block out all of the laser’s light. This is because it is necessary to see where the laser “dot” is, to safely work with the laser. Because the eyewear is blocking some or perhaps all of the laser’s light (for example, a hazardous reflection) you still should use caution even when using laser protective eyewear.
As you use the laser, any other persons in the area should also have the same type of laser protective eyewear as you. Sunglasses are NOT laser protective eyewear. They are not rated (e.g., with Optical Density) to ensure light-attenuating protection. Most sunglasses will not block enough laser light to significantly reduce hazardous exposures.
Some green laser pointers may have built-in lenses or screw-on accessories, in order to make the laser “dot” sharper or fuzzier. Any device that can focus the dot to be sharper, or the beam to be tighter than its normal width, will increase the hazard range and the risk of injury. Use extra caution when the beam is focused.