Risk Management Services

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Classification and Standards

Laser Safety and Program Development

Laser classification and exposure standards are listed in:

• ANSI Z136.1 2007 The Safe Use of LASERS***

• ANSI Z136.2 1988 Safe Use of Optical Fiber Communication Systems Utilizing LASER diode and LED sources

• ANSI Z136.3 1988 Safe Use of LASERS in Health Care Facilities

WorkSafeBC has adopted the above standards.

The classification for most lasers is provided by the manufacturer.

Classification and Exposure Standards

• Class 1, Class 1M

Laser Classification

Both ANSI Z136.1-2007 and IEC 60825-1 use the same laser classes. However, the definitions of the class limits are different in the two standards. Class 1M and 2M vary because of different measurement conditions. The wavelength range is also different for class 1M. Class 2 lasers are the same under both standards. Class 1 and class 3R lasers are the same in the visible and near IR, but differences exist in the UV and far IR. Class 3B limits are similar in the visible and near IR for CW and repetitive pulse lasers, but the limits for single pulse lasers are different for short pulses. Additional differences exist in the UV and far IR.

• Class 2, Class 2M

• Class 3R, Class 3B • Class 4

Class 1 lasers do not emit harmful levels of radiation and are, therefore, exempt from control measures. As a matter of good practice, unnecessary exposure to Class 1 laser light should be avoided (may be considered a higher class during maintenance or service).

* CD-ROM players/drives

Nd:YAG Laser Marker

Class 1 Lasers

• Safe during normal use • Low power or enclosed beam

• Incapable of causing injury • Label not required

Class 2 lasers emit accessible laser light in the visible region and are capable of creating eye damage through chronic exposure.

Aversion response within 0.25 second when exposed to Class 2 laser light. This blink reflex provides adequate protection.

It is possible, however, to overcome the blink reflex and to stare into a Class 2 laser long enough to cause damage to the eye.

Class 2 lasers have power levels less than 1 mW.

* Alignment applications, supermarket scanners

Class 2 Lasers

CLASS II LASER PRODUCT

Laser Radiation Do Not Stare Into Beam

Helium Neon Laser 1 milliwatt max/cw

Special-purpose lasers not intended for viewing. Power output is less than 1 mW.

Causes injury only when viewed directly for more than 1,000 seconds over an 8 hour day, not continuous exposure.

Many bar-code readers fall into this category.

Class 2a Lasers

M is for magnification.

• A class 1M laser is class 1 unless magnifying optics are used. • A class 2M laser is class 2 unless magnifying optics are used.

If these lasers are viewed with magnifying or colleting optics, more light enters the eye and the hazard is greater. These lasers can be viewed safely using optical instruments only if appropriate laser safety eyewear or filters are used.

M classes usually apply to expanded or diverging beams.

Class 1M and 2M

Condition 2 Diverging Beam

Condition 1 Expanded Beam

Normally not hazardous when viewed momentarily with the naked eye but aversion response may not provide adequate eye protection.

• CDRH includes visible lasers only, ANSI includes invisible lasers.

• CW maximum power (visible) 5 mW

• They pose severe eye hazards when viewed through optical instruments (e.g., microscopes and binoculars).

* Laser pointers

CLASS IIIa Laser Product

LASER RADIATION-

AVOID DIRECT EYE EXPOSURE

ND:YAG 532nm

5 milliwatts max/CW

Class 3R (formally 3A) Lasers

• Will cause injury upon direct viewing of the beam and specular reflections.

• The power output is 5-500 mW cw or less than 10 J/cm2 for a ¼-s pulsed system.

• Specific control measures must be implemented.

* Research applications

CLASS IIIb Laser Product

LASER RADIATION-

AVOID DIRECT EXPOSURE TO BEAM

2w ND:YAG Wavelength: 532 nm

Output Power 80 mW

Class 3B Lasers

Class 4 Lasers

Class 4 lasers pose eye hazards, skin hazards, and fire hazards. Viewing of the beam and of specular reflections or exposure to diffuse reflections can cause eye and skin injuries.

All lasers with power levels greater than 500mW CW or greater than 10 J/cm2 for a 1/4-s pulsed system.

Full control measures must be implemented.

* Research, manufacturing

CLASS IV Laser Product

VISIBLE LASER RADIATION-

AVOID EYE OR SKIN EXPOSURE TO

DIRECT OR SCATTERED RADIATION

2w Nd:YAG

Wavelength: 532 nm

Output Power 20 W Photo: Keith Hunt - www.keithhunt.co.uk Copyright: University of Sussex, Brighton (UK)

Class 4 Lasers

250 Watt Class 4 CO2 LASER

Beam moving at 2.5 cm/sec along hot-dog

• Class 1 Incapable of causing injury during normal operation

• Class 1M Incapable of causing injury during normal operation

unless collecting optics are used

• Class 2 Visible lasers incapable of causing injury in 0.25 s.

• Class 2M Visible lasers incapable of causing injury in 0.25 s

unless collecting optics are used

• Class 3R Marginally unsafe for intrabeam viewing; up to 5 times the class 2 limit for visible lasers or 5 times the class 1 limit for invisible lasers

• Class 3B Eye hazard for intrabeam viewing, usually not an eye

hazard for diffuse viewing

• Class 4 Eye and skin hazard for both direct and scattered exposure

Laser Classification Summary