The above is a look at the biological whys and wherefores behind what go into what classifies a laser device to a certain hazard level. Now, we'll get to the far simpler aspect of what the laser classification levels ARE.

The FDA is the event horizon of laser classification; they define the classes and what is or is not restricted to certain uses. One will find ANSI standards that outline laser safety programs for use of lasers in a work environment, by laser classification as defined by the FDA.

Basically, look for the stickers on the device. They will tell you what you basically need to know about a device, though the NOHD/NSHD may not be on it, and NOHD is still the center of gravity of the hazards that commercially-available, firearms-specific lasers present. Look to user manuals if that info is not present on the stickers. If it's not in the user manuals, call the manufacturer. If they do not know or cannot/will not tell you the NOHD....DO NOT USE THAT DEVICE. For all you know, it was slapped together in the back of somebody's El Camino.

-MINIMUM info on a hazard label should include: wavelength, power output (in milliwatts, if applicable; mW), the "universal" symbol for laser (the star-looking thing with the horizontal line coming from it; truly universal only to the office-wog that came up with it.....), and the hazard classification.
-Lasers with multiple power settings, modes, apertures or other features are rated to their highest possible hazard level.
-Note that the language on the warning stickers gets stronger as the hazard classification increases.

Class 1 - Basically, low-power lasers, such as those commonly found in commercially available laser range finders. These are essentially eye-safe, though it's still a bad idea to get into the habit of getting into a staring contest with any laser.
  • may be pulsed or continuous moded
  • no known hazards, up to 5cm optical aids
  • no safety requirements
  • no warning sticker required

NOTE: A device that contains a laser that is not exposed may be classified Class 1, even if it contains a Class 4 laser, because the aperture or emitter is buried within it, such as large printers/copiers that use heat derived from a laser to dry inks or toners; the emitter is not exposed, and DO NOT try to expose it because you’re curious; forget you….they can jack up the people around you, too. You have no more right to blind or damage the eyesight of those around you than you do to shoot them when they are presenting you with no threat. Spare everybody the trouble, and just stare at the sun through a scope until you're eligible for a free dog...that way you're only dicking with your lifestyle.
Example: Laser Devices DBAL-I2

Class 2 - Also low-power lasers, but high enough to be potentially hazardous if viewed for more than .25sec.
  • will be visible laser ONLY
  • will not be single pulse; repetitive pulse and continuous ONLY

Example: UPC bar-code scanners, many office laser pointers.

Class 2.jpg

Class 3R - formerly known as Class 3a. Relatively high-power, compact systems.
  • hazardous to view under virtually any conditions within the NOHD
  • may be pulsed, continuous, or have multiple modes.

Example: Insight XM6, Surefire X400.

Class 3R.jpg

Class 3B - formerly known as Class 3b. High powered laser systems. Restricted items.
  • direct exposure to beam can cause instananeous damage under certain conditions and within the NOHD.
  • danger from specular reflections

Example: most weapon-mounted AN/PEQ variants, many nonlethal hail and warning lasers such as the BE Meyers GBDIIIc.

Class 3B.jpg

Class 4 - most hazardous classification. Extremely high powered laser systems. Rigidly controlled items.
  • not eye-safe under ANY viewing conditions
  • danger from specular reflections
  • danger from diffuse reflections
  • danger of burns to skin/materiel

NOTE: if any of you get your hands on one of these in anything but a Forward Observer role, or in a shipyard cutting steel or the like, I'd like to get a PM....so I can move to another continent. The "most hazardous" denotation above is sorta like "heavyweight" in the UFC; there is only a minimum and no maximum, which is why you theoretically might see a 215# dude fighting a dude that weighs 4 metric tons.

Class 4.jpg