Health requires safety. There is a laser hazard that the Food and Drug Administration (FDA) is concerned about: the increased availability in stores and on the Internet of certain types of laser products. A laser can be unsafe when misused as a toy or directed at people, vehicles, or aircraft.
The laser acronym stands for light amplification by stimulated emission of radiation. FDA regulates radiation-emitting electronic products, including all types of lasers. Manufacturers of some types of laser products that are powered above 5 mW must obtain permission from FDA before they are sold to the public. This power limit applies to lasers sold to the public for purposes of alignment, surveying, or leveling, and includes lasers used for pointing. Laser projectors powered above 5 mW and the laser light shows that they produce must also be manufactured with permission from FDA.
There are many different types of lasers depending on type of laser medium in use. Laser media commonly include gases such as argon, carbon dioxide, nitrogen or a helium and neon mixture, solid crystals such as ruby, and liquid dyes or chemicals. When energy is applied to the laser medium, it becomes excited and releases energy as particles of light (photons). A pair of mirrors at either end of the sealed tube either reflects or transmits the light (see FDA figure below) in the form of a concentrated stream called a laser beam. Each laser medium produces a beam of a unique wavelength and color
Lasers are employed for a variety of purposes including pointing out objects during a presentation, aligning materials at construction sites and in the home, and by doctors for cosmetic and surgical procedures. Some of the laser applications in daily life are CD and DVD players; fiber-optic communication, bar code scanners; dental drills; laser-guided tools, such as levels; and laser printers.
- Laser light can be emitted in a tight beam that does not grow in size at a distance from the laser. This means that the same degree of hazard can be present both close to and far from the laser.
- The eye can focus a laser beam to a very small, intense spot on its retina, which can result in a burn or blind spot.
The FDA requires labels on most laser products that contain a warning about the laser radiation and other hazards, and a statement certifying that the laser complies with FDA safety regulations. The label must also state the power output and the hazard class of the product. The FDA recognizes four major hazard classes (I to IV), including two subclasses (IIIa and IIIb), of lasers--ranging from those that pose no known hazard to those that pose serious danger if used improperly. The higher the class is, the more powerful the laser is. Consumer laser products are generally in classes I, II, and IIIa, while lasers for professional use may be in classes IIIb and IV.
FDA Tips for Consumers
Surveying, leveling, or alignment laser products and demonstration laser products mentioned directly above that are powered above 5 mW with no label that indicates they were manufactured under a variance present a serious safety hazard and are not legal for sale.