변경된 레이저 안전 등급
Class
1M
LASER
RADIATION
DO NOT VIEW DIRECTLY WITH OPTICAL INSTRUMENTS
CLASS 1M LASER PRODUCT
DO NOT VIEW DIRECTLY WITH OPTICAL INSTRUMENTS
CLASS 1M LASER PRODUCT
A Class 1M laser is safe
for all conditions of use except when passed through magnifying optics such as
microscopes and telescopes. Class 1M lasers produce large-diameter beams, or
beams that are divergent. The MPE for a Class 1M laser cannot normally be
exceeded unless focusing or imaging optics are used to narrow the beam. If the
beam is refocused, the hazard of Class 1M lasers may be increased and the
product class may be changed. A laser can be classified as Class 1M if the
power that can pass through the pupil of the naked eye is less than the AEL for
Class 1, but the power that can be collected into the eye by typical magnifying
optics (as defined in the standard) is higher than the AEL for Class 1 and
lower than the AEL for Class 3B.
Class
2
LASER
RADIATION
DO NOT STARE INTO BEAM
CLASS 2 LASER PRODUCT
DO NOT STARE INTO BEAM
CLASS 2 LASER PRODUCT
A Class 2 laser is safe
because the blink reflex will
limit the exposure to no more than 0.25 seconds. It only applies to
visible-light lasers (400–700 nm). Class-2 lasers are limited to 1 mW
continuous wave, or more if the emission time is less than 0.25 seconds or if
the light is not spatially coherent. Intentional suppression of the blink
reflex could lead to eye injury. Many laser pointers and
measuring instruments are class 2.
Class
2M
LASER
RADIATION
DO NOT STARE INTO BEAM OR VIEW
DIRECTLY WITH OPTICAL INSTRUMENTS
CLASS 2M LASER PRODUCT
DO NOT STARE INTO BEAM OR VIEW
DIRECTLY WITH OPTICAL INSTRUMENTS
CLASS 2M LASER PRODUCT
A Class 2M laser is safe
because of the blink reflex if not viewed through optical instruments. As with
class 1M, this applies to laser beams with a large diameter or large
divergence, for which the amount of light passing through the pupil cannot
exceed the limits for class 2.
Class
3R
LASER
RADIATION
AVOID DIRECT EYE EXPOSURE
CLASS 3R LASER PRODUCT
AVOID DIRECT EYE EXPOSURE
CLASS 3R LASER PRODUCT
A Class 3R laser is
considered safe if handled carefully, with restricted beam viewing. With a
class 3R laser, the MPE can be exceeded, but with a low risk of injury. Visible
continuous lasers in Class 3R are limited to 5 mW. For other wavelengths
and for pulsed lasers, other limits apply.
Class
3B
LASER
RADIATION
AVOID EXPOSURE TO BEAM
CLASS 3B LASER PRODUCT
AVOID EXPOSURE TO BEAM
CLASS 3B LASER PRODUCT
A Class 3B laser is
hazardous if the eye is exposed directly, but diffuse reflections such as those
from paper or other matte surfaces
are not harmful. The AEL for continuous lasers in the wavelength range from
315 nm to far infrared is 0.5 W. For pulsed lasers between 400 and
700 nm, the limit is 30 mJ. Other limits apply to other wavelengths
and to ultrashort pulsed lasers. Protective eyewear is
typically required where direct viewing of a class 3B laser beam may occur.
Class-3B lasers must be equipped with a key switch and a safety interlock.
Class 3B lasers are used inside CD and DVD writers, although the writer unit
itself is class 1 because the laser light cannot leave the unit.
Class
4
LASER
RADIATION
AVOID EYE OR SKIN EXPOSURE TO
DIRECT OR SCATTERED RADIATION
CLASS 4 LASER PRODUCT
AVOID EYE OR SKIN EXPOSURE TO
DIRECT OR SCATTERED RADIATION
CLASS 4 LASER PRODUCT
Class 4 is the highest and
most dangerous class of laser, including all lasers that exceed the Class 3B
AEL. By definition, a class 4 laser can burn the skin, or cause devastating and
permanent eye damage as a result of direct, diffuse or indirect beam viewing.
These lasers may ignite combustible materials, and thus may represent a fire
risk. These hazards may also apply to indirect or non-specular reflections of
the beam, even from apparently matte surfaces—meaning that great care must be
taken to control the beam path. In most states it is illegal to sell
preassembled class 4 lasers, however a citizen can construct a class 4 laser
for personal use. Class 4 lasers must be equipped with a key switch and a
safety interlock. Most industrial, scientific, military, and medical lasers are
in this category.
기존의 레이저 안전등급
Class
I
Inherently safe; no
possibility of eye damage. This can be either because of a low output power (in
which case eye damage is impossible even after hours of exposure), or due to an
enclosure preventing user access to the laser beam during normal operation,
such as in CD players or laser printers.
Class
II
The blink reflex of the
human eye (aversion
response) will prevent eye damage, unless the person
deliberately stares into the beam for an extended period. Output power may be
up to 1 mW. This class includes only lasers that emit visible
light. Most laser pointers are
in this category.
Class
IIa
A region in the low-power
end of Class II where the laser requires in excess of 1,000 seconds of
continuous viewing to produce a burn to the retina. Commercial laser scanners
are in this subclass.
Class
IIIa
Lasers in this class are
mostly dangerous in combination with optical instruments which change the beam
diameter or power density, though even without optical instrument enhancement
direct contact with the eye for over two minutes may cause serious damage to
the retina. Output power does not exceed 5 mW. Beam power density may not
exceed 2.5 mW/cm2 if
the device is not labeled with a "caution" warning label, otherwise a
"danger" warning label is required. Many laser sights for firearms and laser
pointers are
in this category.
Class
IIIb
Lasers in this class may
cause damage if the beam enters the eye directly. This generally applies to
lasers powered from 5–500 mW. Lasers in this category can cause permanent
eye damage with exposures of 1/100th of a second or less depending on the
strength of the laser. A diffuse reflection is generally not hazardous but specular reflections can
be just as dangerous as direct exposures. Protective eyewear is recommended
when direct beam viewing of Class IIIb lasers may occur. Lasers at the high
power end of this class may also present a fire hazard and can lightly burn
skin.
Class
IV
Lasers in this class have
output powers of more than 500 mW in the beam and may cause severe,
permanent damage to eye or skin without being magnified by optics of eye or
instrumentation. Diffuse reflections of the laser beam can be hazardous to skin
or eye within the Nominal Hazard Zone. Many industrial, scientific, military
and medical lasers are in this category. Many handheld lasers ("laser
pointers") at this output level are now available in this category.
