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
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,
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
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
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.
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
Laser Product Hazard
non-hazardous. Hazard increases if
viewed with optical aids, including
magnifiers, binoculars, or telescopes.
increases when viewed directly for long
periods of time. Hazard increases if
viewed with optical aids.
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.
skin hazard from direct beam and
immediate eye hazard when viewed
laser light show projectors
skin hazard and eye hazard from exposure
to either the direct or reflected beam;
may also present a fire hazard.
laser light show projectors
lasers used to perform LASIK eye
TITLE 18, CHAPTER 2, Section 39A, signed into law in 2012, makes
it illegal to aim a laser pointer at an aircraft or aircraft
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
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.
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.
with class 3B and class 4 lasers can protect their eyes with
safety goggles which are designed to absorb light of a
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.
International Commission on Non-Ionizing Radiation Protection Guidelines on
Limits to Exposure to Lasers
Minimize Your Risk:
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.
The FDA recommends that consumers be
cautious when buying laser products over the internet.
Consumers may unknowingly purchase an illegal laser product
or may lose their money if the illegal product is refused
entry into the U.S. or destroyed.
be aware that:
- Medical lasers may only be sold to licensed medical
- Class IIIb and class IV laser light show projectors,
identified as such on the label, may only be sold by or to
individuals or firms with current, approved laser light show
variances from FDA. Laser products that are advertised as
uncertified components may only be sold to other
manufacturers and may not be sold to the public for general
products should have certification and identification labels
stating the product complies with the federal laser
with 21 CFR 1040.10 and 1040.11
with 21 CFR Chapter 1, Subchapter J
Manufactured or distributed by...
- Date of
should have a warning label advising the user to avoid
exposure to the laser radiation.
Read more about
FDA Consumer Safety Alert:
Internet Sales of Lasers
The FDA provides additional consumer safety
tips on their web page
Illuminating the Hazards of Powerful Laser
Additionally, FDA warns of lasers in toys:
Consumer Update: Laser Toys
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.
Institute of Standards and Technology (NIST) Lasers Study
of Laser Safety Professionals