Radiation Protection Section -

Lasers: Most lasers are a source of non-ionizing radiation. Lasers typically emit optical light (UV, visible light, IR). Infrared and UV can cause corneal burns, cataracts, and skin burns. Common lasers include CO₂ IR laser; helium - neon, neodymium YAG, and ruby visible lasers, and the Nitrogen UV lasers.

Lasers have many important applications. They are used in common consumer devices such as DVD players, laser printers, and barcode scanners. They are used in medicine for laser surgery and various skin treatments, and in industry for cutting and welding materials. They are used in military and law enforcement devices for marking targets and measuring range and speed. Laser lighting displays use laser light as an entertainment medium. Lasers also have many important applications in scientific research.

The laser medium can be a solid, gas, dye (in liquid), or semiconductor. Lasers are commonly designated by the type of lasing material employed.
Solid state lasers have lasing material distributed in a solid matrix, e.g., the ruby or neodymium-YAG (yttrium aluminum garnet) lasers. The neodymium-YAG laser emits infrared light at 1.064 micrometers.
Gas lasers, the most common of which are helium and helium-neon lasers, have a primary output of a visible red light. CO2 lasers emit energy in the far-infrared range, 10.6 micrometers, and are used for cutting hard materials.
Excimer lasers use reactive gases such as chlorine and fluorine mixed with inert gases such as argon, krypton, or xenon. When electrically stimulated, a pseudomolecule or dimer is produced and when lased, produces light in the ultraviolet range. "Exicemer" is derived from the terms excited and dimers.
Dye lasers use complex organic dyes like rhodamine 6G in liquid solution or suspension as lasing media. They are tunable over a broad range of wavelengths.
Semiconductor lasers, sometimes called diode lasers, are not solid-state lasers. These electronic devices are generally very small and use low power. They may be built into larger arrays, e.g., the writing source in some laser printers or compact disk players.
Free-electron lasers, or FELs, generate coherent, high power radiation that is widely tunable. FELs currently range in wavelength from microwaves, through terahertz radiation and infrared, to the visible spectrum, to soft X-rays. FELs have the widest frequency range of any laser type. While FEL beams share the same optical traits as other lasers, such as coherent radiation, FEL operation is quite different. Unlike gas, liquid, or solid-state lasers, which rely on bound atomic or molecular states, FELs use a relativistic electron beam as the lasing medium, hence the term free-electron.

Several organizations concern themselves with laser safety. These organizations include the American National Standards Institute (ANSI), the Center for Devices and Radiological Health (CDRH) of the Food and Drug Administration (FDA), the Department of Labor's Occupational Safety and Health Administration (OSHA), and the Council of Radiation Control Program Directors (CRCPD). Several state governments and CRCPD have developed a model state standard for laser safety.

All laser devices distributed for both human and animal treatment in the U.S. are subject to Mandatory Performance Standards. They must meet the Federal laser product performance standard and must submit an "initial report" to CDRH's Office of Compliance prior to distributing the product (see 21 CFR 1000 - 1040). This performance standard specifies the safety features and labeling that all laser products must have in order to provide adequate safety to users and patients. A laser product manufacturer must certify that each model complies with the standard before introducing the laser into U.S. commerce. Compliance with standards must also be shown before clinical investigations prior to device approval.

Certification of a laser product means that each unit has passed a quality assurance test and that it complies with the performance standard. The firm that certifies a laser product assumes responsibility for product reporting, recordkeeping, and notification of defects, noncompliances, and accidental radiation occurrences, as specified in sections 21 CFR 1000-1010. A certifier of a laser product is required to report the product via a Laser Product Report submitted to CDRH. Reporting guides and related regulatory information are available from the Radiation-Emitting Products web site. Distribution of any certified laser products internationally also requires submission of the report.

The Food and Drug Administration (FDA) recognizes four major hazard classes (I to IV) of lasers, including three subclasses (IIa, IIIa, and IIIb). The higher the class, the more powerful the laser and the potential to pose serious danger if used improperly. Consumer laser products are generally in classes I, II, and IIIa, while lasers for professional use may be in classes IIIb and IV. The labeling for Classes II–IV must include a warning symbol that states the class and the output power of the product.

The FDA requires labels on most laser products that contain a warning about the laser radiation and other hazards, as well as a statement certifying that the laser complies with FDA safety regulations.

Class FDA	Class IEC	Laser Product Hazard	Product Examples
I	1, 1M	Considered non-hazardous. Hazard increases if viewed with optical aids, including magnifiers, binoculars, or telescopes.	laser printers CD players DVD players
IIa, II	2, 2M	Hazard increases when viewed directly for long periods of time. Hazard increases if viewed with optical aids.	bar code scanners
IIIa	3R	Depending on power and beam area, can be momentarily hazardous when directly viewed or when staring directly at the beam with an unaided eye. Risk of injury increases when viewed with optical aids.	laser pointers
IIIb	3B	Immediate skin hazard from direct beam and immediate eye hazard when viewed directly.	laser light show projectors industrial lasers research lasers
IV	4	Immediate skin hazard and eye hazard from exposure to either the direct or reflected beam; may also present a fire hazard.	laser light show projectors industrial lasers research lasers lasers used to perform LASIK eye surgery

U.S.C. TITLE 18, CHAPTER 2, Section 39A, signed into law in 2012, makes it illegal to aim a laser pointer at an aircraft or aircraft flight path.

OSHA standards regarding lasers This website highlights OSHA standards, directives (instructions for compliance officers), standard interpretations (official letters of interpretation of the standards), and national consensus standards related to laser hazards.

OSHA Technical Manual on lasers and laser hazards.

International Regulations:

The International Electrotechnical Commission (IEC) is the authoritative worldwide body responsible for developing consensus global standards in the electrotechnical field. IEC is dedicated to the harmonization and voluntary adoption of these standards, supporting the transfer of electrotechnology, assisting certification and promoting international trade.

Scientific/Medical:

All lasers pose potential danger of skin, organ and tissue damage as a result of extended exposure or staring into the beam. Thermal radiation due to heat generated during extended contact is also a concern. People working with class 3B and class 4 lasers can protect their eyes with safety goggles which are designed to absorb light of a particular wavelength.

Infrared lasers with wavelengths beyond about 1.4 micrometers are often referred to as "eye-safe" because the cornea strongly absorbs light at these wavelengths, protecting the retina from damage. The label "eye-safe" can be misleading, as it only applies to relatively low power continuous wave beams. A high power or Q-switched laser at these wavelengths can burn the cornea, causing severe eye damage, and even moderate power lasers can injure the eye.

The FDA states that, "laser pointers are misused when they are directed at people or treated as toys. The light energy from a laser pointer aimed into the eye can be more damaging than staring directly into the sun. And the startling effect of a bright beam of light can cause serious accidents when aimed at a driver in a car, a pilot in a plane, or even a person holding a cup of hot coffee." Read more on the FDA website about Illuminating Facts about Lasers.

National Institute of Standards and Technology (NIST) researchers tested 122 laser pointers and found that nearly 90 percent of green pointers and about 44 percent of red pointers tested were out of compliance with federal safety regulations. National Institute of Standards and Technology (NIST) Lasers Study