1. LASER SAFETY
References: Lippincott, AORN 2015 standards, laser (OSHA)

2. LASER is an acronym for BASIC LASER ENERGY AMPLIFICATION BY
LIGHT
AMPLIFICATION BY
“STIMULATED”
EMISSION OF
RADIATION

3. Early 1900’s, Einstein described a theory that involved stimulation of matter to cause the release of energy.
Incident Photon
Incident Photon
Excited Atom
Light is an electro magnetic wave with different wavelengths representing unique colors in the visible light spectrum.
Stimulated Photon
same wavelength
same direction
in phase

4. Alaskan Lasers BARTLETT MEMORIAL HOSPITAL FAIRBANKS MEMORIAL HOSPITAL
ALASKA NATIVE MEDICAL CENTER
HOLMIUM, IRIDEX
ALASKA REGIONAL HOSPITAL
CO2, HOLMIUM, GREEN LIGHT
BARTLETT MEMORIAL HOSPITAL
FAIRBANKS MEMORIAL HOSPITAL
CO2, HOLMIUM
MAT-SU REGIONAL HOSPITAL
CO2, KTP, HOLMIUM
PROVIDENCE HEALTH SYSTEMS ALASKA
C02, KTP, HOLMIUM, GREEN LIGHT
CO2
These are the lasers you will find at your respective institutions.

5. TYPES: CO2 KTP DIODE HO:YAG HE:NE
WAVE
LENGTH
ACTIVE
MEDIUM
ABSORBED BY
USES
10,600 nm
CO2, N2, He
Water
Gyn, ENT,
Plastics
532nm
(frequency doubled YAG)
Nd:YAG passes thru KTP crystal
Hemoglobin,
Melanin
Eye, Urologic,
Gyn nm
Semi-conductor
Hemoglobin
Eye
2140 nm
Holmium in YAG
Urology
633 nm
Helium
Dark-colored
Tissue
Visible-Aiming beam
TYPES OF LASER
WAVELENGTH
ACTIVE MEDIUM
More about the Lasers that we have in Alaska.
CO2 is a carbon dioxide laser beam in the infrared spectrum, so it is invisible to naked eye. HeNe beam is tagged with the beam so you can see it.
KTP is a visible beam created when Nd:YAG (Neodynium Yittrium Aluminum Garnate), a 1064nm beam is passed thru a KTP (Potassium Titianyl phosphate) crystal. The result doubles the frequency, hence the KTP beam is now 532nm.
Diodes are found in disc players and computers and are very compact and reliable.
Holmium is a very common laser used to break up stones in the urinary tract system.
Again, generally HeNe is used as a tag for invisible laser energy so that it becomes safer to use.

6. LASER CLASSIFICATION SUMMARY
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.
BAR CODE SCANNERS
Class 2M Visible lasers incapable of causing injury in 0.25 s
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 (RED LASER POINTERS)
Class 3B Eye hazard for intrabeam viewing, usually not an eye
hazard for diffuse viewing (MEDICAL LASERS)
Class 4 Eye and skin hazard for both direct and scattered exposure
MOST MEDICAL LASERS
Both ANSI Z and IEC use the same laser classes. However, the definitions of the class limits are different in the two standards.
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 1M and 2M vary because of different measurement conditions. The wavelength range is also different for class 1M.
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.
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7. CLASS 4 LASER Hazard Classification
Class 4 lasers above 500 milliwatts in power can injure you if viewed directly or by viewing either the specular and diffuse reflections of the beam.
These lasers can also present a fire hazard.
A danger sign will label this laser.
Eye and skin protection are required.
All medical laser used in our operating rooms are considered Class 4 and require stringent safety measures.
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8. Hazards Potential for: Eye Injuries Tissue Burns Plume Inhalation Fire
Electrical
(To name a few)
In general, laser therapy is safe, although bleeding and scarring can result. One pronounced hazard to both the patient and the treatment staff is eye damage or other injury caused by unintended laser beam reflection.

9. TYPES OF LASER EYE EXPOSURE
INTRABEAM VIEWING
LASER
DIFFUSE REFLECTION
SCATTERED LIGHT
MIRROR
SPECULAR REFLECTION
REFLECTED BEAM
ROUGH
SURFACE
Intrabeam viewing is the situation when a collimated laser beam enters the eye, producing the smallest focused spot on the retina and the greatest eye hazard.
A specular (mirror) reflection of the beam into the eye produces the same focal spot size and the same level of hazard.
Viewing a diffuse reflection is much less hazardous. In this case much less light enters the eye, and the light that does enter the eye has been scattered and is no longer coherent. This means that the spot on the retina is larger. Thus, the light is less concentrated and the hazard is reduced. If the diffuse reflection is too intense, an eye injury can result. Class 4 lasers are those lasers that produce hazardous diffuse reflections.
The hazard from a diffuse reflection often depends on the size of the diffuse spot. Smaller spots result in greater diffuse hazards.
This corresponds with the types of tissue interaction a laser beam has as well. It is transmitted, relected, scattered and absorbed.
For this reason, anyone in the surgical suite, including the patient, must wear special protective eyewear to filter laser light, and the surgeon must use special nonreflective instruments. Access to the surgical suite must be controlled strictly, and all windows must be covered.
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10. Visible and Near-Infrared Radiation Causes Retinal Burn
Green light, KTP lasers, Diode. Nd:YAG

11. Consider CO2 @ 10,600 nm and the effect on an eye….
Mid and Far Infrared - causes damage to the cornea by increased temperature in tears and tissue water.
Consider 10,600 nm and the effect on an eye….
Holmiun and CO2

12. MULTIPLE PULSE RETINAL INJURY
This is an image of the retina of a human who experienced an eye injury from a repetitive pulse near infrared laser. The beam was invisible. In such cases people do not usually realize they are being exposed until their vision has been severely effected. The person’s eye was moving during this exposure. This resulted in a line of laser burns on the retina. This is a color enhanced image to better show the laser damage.
The macula of the eye is located out of the photo to the lower left. This individual was lucky that the damage did not extend into the macula.
The laser safety eyewear would have prevented this injury.
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13. HAZARDS CONTINUED: SKIN – Inadvertent, reflected beam
PLUME – Toxic, similar to ESU smoke
FIRE – Reflected beam, drape, solutions, methane gas, ENDOTRACHEAL TUBE!
ELECTRICAL –HIGH- Voltage equipment
Fluids too close
ALEXANDERS CARE OF THE PATIENT IN SURGERY, 2011
Plume:
In your Alexanders’ text, you will find research and reports on plume hazards. In 1991 it was reported that a Norwegian surgeon did indeed have a laryngeal biopsy done that revealed human papillomavirus DNA consistent with anogenital condyloma he had vaporized using a laser.
Fire:
Considering what you know about laser energy and it’s characteristics, you can begin to appreciate it’s ability to create a tremendous amount of heat and destruction when it is focused. A reflected beam can be as intense as a direct beam, resulting in burns on skin, eyes and drapes. Yes, methane gas has the potential to spark a fire… Regarding fire hazards, an Endotracheal tube is a conduit for oxygen, part of the fire triangle. This has the potential to become a blowtorch if it catches on fire. It is one of those situations you never want to be in… So, prevention is your absolute goal!
Electrical:
This machine is carrying a lot of voltage and any fluids near it causing a spill onto the machine make it potentially unsafe for the operators first.

14. SAFETY Terminology- NHZ/OD Laser safety officer
Safe practice –laser operator
Controlled access
Signage/ glasses
Smoke evacuation
Et tube use
Fire and electrical safety
So, given all that gloom and doom, how do we create a safe environment?

15. Nominal Hazard Zone (NHZ)
Terms:
Nominal Hazard Zone (NHZ)
This zone describes the region within which the level of direct, reflected, or scattered (diffuse) laser radiation is above the allowable MPE.
KEY: Consider ENTIRE OR Room AS NHZ
Optical Density (O.D.)
This is the ability of material to absorb light.
You will see this on the goggles/glasses.

16. What safety precautions are required?
Who has primary responsiblity for laser safety any time a class 4 laser is operated?
The person operating the laser always has the primary responsibility for all hazards associated with laser use.
What safety precautions are required?

17. SAFE PRACTICE & CONTROLLED ACCESS
Recommended that there be a dedicated laser operator for each procedure
Standby used liberally. Direct conversation between surgeon and laser operator
Keep foot pedals separated
Signs on all entrances that state type of laser w/ matching glasses
Control of traffic in room
Entire room considered within NHZ!
Windows:
Covered (exception – co2 lasers)
Easiest to remember to always cover!
OSHA: Key must be removed when laser is not in use!

18. LASER SAFETY EYEWEAR
Eyewear would have prevented most laser eye injuries, but it does not make the wearer invulnerable.
It is never safe to stare into a laser beam, even if wearing laser protective eyewear.
Eyewear must be labeled with the appropriate optical density and wavelength for the laser in use.
Laser safety eyewear is available in glass or plastic for all laser wavelengths. The required Optical Density of the eyewear is determined in the hazard analysis performed by the LSO.
Eyewear should never be viewed as the first control measure to be applied. In all cases engineering and procedural controls should be devised to reduce and limit the possible exposure to hazardous laser light. The use of eyewear should then be required as a last line of defense in case everything else fails. Most laser eye injuries have occurred when other controls proved inadequate and the worker was not wearing eyewear.
The greatest risk of eye injury occurs when near IR lasers are operated with the beam exposed.
Eyewear should always be worn when a class 3B or class 4 beam is accessible.
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19. EYE PROTECTION Wavelength/ O.D. Matches type of laser
Do not use color as your choice!
Use glasses with side shields
Hang with laser signs at each entry
Use filters, fixed or semi-permanent, in microscopes
Clean/ inspect. Replace if questionable
Patient Protection:
Awake – eyewear that matches laser
General – water base lubricant/tape
Nd:YAG – foil type covering/ glasses
Facial resurfacing – special contacts

20. SURGICAL SMOKE Surgical smoke is generated from use of lasers
Hazardous chemical compounds have been noted in surgical smoke
Smoke evacuation
Utilize evacuation system for 0.1 microns w/ filters (ULPA/HEPA)
Use of laser masks (0.1 Microns)
Hold nozzle close to source of plume
Discard filters as biohazard
Either ultra-low particulate air or high efficiency particulate air filters can be used. These may be in-line or free-standing systems.

21. ENDOTRACHEAL TUBES
FDA approved, non flammable, laser- resistant (or wrapped w/ same)
Do not use pvc tubes
Inflate cuff with saline (tint w/ methylene blue)
Externally protect with wet cottonoids
Use lower concentration of oxygen (less than 30%) or room air

22. FIRE SAFETY No alcohol/ no pooling during prep No liquids on machine
No flammable ointment on patient eyes
Water/saline on field
Cover anal area to block methane
Fire extinguisher immediately available
Endotracheal tube fire:
Disconnect anesthesia gases
Remove tube/ extinguish flames w/ NACL
Ready to do bronchoscopy/ trach
Equipment fire: shut off power source
Laser should not be activated in the presence of flammable agents until the agents are dry and vapors have dissipated.

23. ELECTRICAL SAFETY Check all cords and cables for defects.
No liquids near laser.
Foot pedal covered.
Extension cords not ever used!
Control traffic around cords and fibers.
Emergency shutdown procedure

24. DOCUMENTATION Laser Safety Checklist Laser Log
Every laser should have a safety checklist that is to be followed. This will help key important safety features to watch for.
Laser logs can be handwritten or completed through computer charting . Check with your facility.

25. ELECTROMAGNETIC SPECTRUM
Visible
Radio
Gamma Ray
X-ray
Ultraviolet
Infrared
Microwaves
Radio
Short Wavelength
Long Wavelength
The electromagnetic spectrum extends from gamma rays at the short wavelength end to radio waves at the long wavelength end. The visible spectrum is a narrow slice somewhere in the middle, with blue light at the short wavelength end and red light at the long wavelength end.
The next shortest wavelength region from the visible is the ultraviolet. Ultraviolet light causes sunburn, skin cancer, and cataracts.
The next longest wavelength region from the visible is the infrared. Infrared light is invisible to the eye but can be felt as heat. It can cause burns to the skin or eyes.
Lasers operate in the ultraviolet, visible, and infrared regions of the spectrum. Lasers in each spectral region present unique safety issues.
Lasers operate in the ultraviolet, visible, and infrared.
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26. LASER COMPONENTS Optical Resonator Active Medium Excitation Mechanism
High Reflectance
Mirror (HR)
Output Coupler
Mirror (OC)
Active
Medium
Output
Beam
Excitation Mechanism
Optical Resonator
All lasers have the same basic design. Most are named for the active medium.
The active medium contains the atoms that produce laser light by stimulated emission. This can be a solid crystal, a gas, a semiconductor junction, or a liquid. The excitation mechanism is the source of energy that excites the atoms to the proper energy level for stimulated emission to occur. Solid state lasers use optical sources for excitation; gas lasers use electrical excitation. The active medium and excitation mechanism together form an optical amplifier. Laser light entering one end of the amplifier will be amplified by stimulated emission as it travels through the active medium.
The optical resonator is a pair of mirrors at the ends of the active medium. These mirrors are aligned to reflect the laser light back and forth through the active medium. The high reflectance mirror has a reflectivity of nearly 100%. The output coupler has a lower reflectance and allows some of the laser light to pass through to form the output beam. The fraction of the light that is allowed to pass through the output coupler depends on the type of laser. Low power lasers usually require most of the laser light to be reflected to keep the stimulated emission process going, and only a few percent can be allowed to pass into the output beam. In very high power pulsed lasers, the output coupler may have a transmission of over 50%.
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27. Near Ultraviolet – Contributes to certain forms of cataracts Xenon Chloride Excimer: Instant cataract, 308 nm pulsed laser
Excimer lasers: ex. Lasik, Halogen, xenon, argon
Can cut through any solid material (from diamond to corneas)
Used for cutting biological tissue where a clean cut is required without thermal damage to the surrounding tissue.

28. LASER SAFETY STANDARDS
The Federal Laser Product Performance Standard (FLPPS)
of the Center for Devices and Radiological Health (CDRH)
This is federal law and applies to the manufacture of lasers.
The American National Standard for Safe Use of Lasers (ANSI Z136.1) This is a VOLUNTARY Standard that applies to the use of lasers.
It is “recognized by” :
The Occupational Safety and Health Administration (OSHA)
IEC International Standard
All laser products sold in the United States must comply with the FLPPS. It requires that all lasers be classified and that specified engineering controls must be included in each class product.
The ANSI Standard is a voluntary, user standard. It is “good advice” for laser users and is expected to be followed voluntarily because it is the best approach to assure safe use of lasers. It was written for laser users by laser users, and it is the consensus of the laser safety community that it was the best document that could be published at the time. A new revision is published every few years. OSHA requires that all organizations using lasers have a Laser Safety Program that meets the requirements of the ANSI Standard.
The IEC International Standard applies to both the manufacture and use of lasers. It has not been adopted as the standard in the United States because both the federal government and the ANSI committee do not agree with all the provisions of this standard. Lasers classified and labeled in accordance with this standard may be sold in the United States.
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29. LASER SPECTRUM Retinal Hazard Region
Gamma Rays X-Rays Ultra- Visible Infrared Micro Radar TV Radio
violet waves waves waves waves
Wavelength (m)
LASERS
Retinal Hazard Region
Ultraviolet
Visible
Near Infrared
Far Infrared
Wavelength (nm)
Lasers operate in the ultraviolet, visible, near infrared, and far infrared regions of the spectrum.
Visible light has a wavelength range of 400 – 700 nm and can be seen by the eye. The fact that you can see this light helps you avoid hazardous exposures.
The near infrared has a range of 700 – 1400 nm. It cannot be seen because the retinal receptors do not work at these wavelengths. However, the optical elements of the eye transmit the NIR and focus these wavelengths on the retina. This produces an invisible retinal hazard and the potential for serious eye injury in the near IR. The most stringent laser safety precautions are required in this wavelength range. It also contains several of the most useful lasers.
The far infrared is completely absorbed by water before any of the light reaches the retina. This protects the retina from damage. These wavelengths can damage other parts of the eye, but the absorption is spread over a larger area resulting in a larger allowed exposure.
The ultraviolet has the potential for photochemical damage to both eyes and skin. This means that it must be handled to avoid long term hazardous exposures at low levels.
ArF
193
XeCl
308
HeNe
633
Ruby
694
CO2
10600
Communication
Diode
1550
KrF
248 Ar
488/515 2w
Nd:YAG
532
Alexandrite
755
GaAs
905
Nd:YAG
1064
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30. WAVE NATURE OF LIGHT Blue: l = 400 nm
Wavelength
Red: l = 700 nm
Blue: l = 400 nm
Light is an electromagnetic wave.
Different wavelengths in the visible spectrum are seen by the eye as different colors.
Light is an electromagnetic wave. It consists of oscillating electric and magnetic fields traveling through space. This figure is a representation of the electric field of a light wave.
The wavelength is the distance between two peaks on the wave. Different wavelengths are seen by the eye as different colors. Blue light has a wavelength of about 400 nm (0.4 mm). Red light has a wavelength of about 700 nm (0.7 mm). (1 nm = m; 1 mm = 10-6 m)
For about three hundred years there was a disagreement among scientists about the nature of light. Some believed light was a wave and others believed that light was a particle. Both factions were eventually able to support their positions with experimental evidence. It was not until the beginning of the twentieth century that the answer was discovered. When light travels through space, it acts like a wave. When light is emitted or absorbed by an atom, it acts like a particle.
The “particle” of light is called a photon. It is not a material particle but rather a “quantum” that acts as though it is located in one place and has definite energy and momentum, like an ordinary particle. A photon is more accurately described as a packet of energy. The energy of a photon is related to the wavelength of the light. Shorter wavelength photons have more energy than long wavelength photons.
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31. LASER CONTROL MEASURES
ANSI Section 4.1
“Control Measures shall be devised to reduce the possibility of exposure of the eye and skin to hazardous levels of laser radiation.”
Types of Control Measures
Engineering
Administrative
Procedural
The ANSI Standard states that the LSO will determine the control measures to be used to reduce possible laser exposures to a level at or below the MPE for all cases in which exposure to a class 3B or 4 laser is possible.
Three types or controls are specified in the Standard:
Engineering controls are features built into the equipment or facility that protect personnel automatically without the need of protective action on the part of the worker.
Administrative controls are policies that limit exposure to laser hazards, such as: only authorized personnel may operate lasers with the interlocks defeated.
Procedural controls are specific procedures to be followed by laser personnel when working with an exposed laser beam. These are usually specified in a Standard Operating Procedure.
The LSO may substitute alternate controls for any control measure required by the Standard if the LSO believes this is the best course of action and that the substitute control measure provides equivalent protection.
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32. LASER HAZARD CLASSES
Lasers are classified according to the level of HAZARD that is possible during normal operation.
Lasers and laser systems are classified according to their level of hazard. The classification of lasers is based on:
The potential hazard of the laser beam, not ancillary hazards.
The hazard during normal operation, not during maintenance or service.
The maximum level of exposure possible.
Lasers may be classified under:
The Federal Laser Product Performance Standard (Also called the CDRH* Standard)
The American National Standard for Safe Use of Lasers
IEC International Standard
* Center for Devices and Radiological Health of the U S Food and Drug Administration
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33. Control Measures for Class 3b and Class 4 Lasers
Engineering Administrative PPE
Protective housing and service panel Interlocks on the protective housing Door interlocks and remote-control connector Beam attenuators and beam shutters
Key switch or padlock Filtered viewing optics and windows Emission delay
Warning lights, emission indicators Beam enclosure
Controlled beam path Laser controlled area Beam stops Remote firing and/or monitoring
Laser safety officer Standard operating procedures Limitations on use by class Entry limitations for visitors Education and training Maintenance and service manuals Marking of protective devices Warning signs and labels
Eyewear Clothing Gloves
THE LASER SAFETY OFFICER (LSO) IS RESPONSIBLE FOR MAKING SURE CONTROL MEASURES ARE IN PLACE

34. MAXIMUM PERMISSIBLE EXPOSURE
MPE limits indicate the greatest exposure that most individuals can tolerate without sustaining injury.
MPE depends on
Wavelength
Output energy and power
Size of the irradiated area
Duration of Exposure
Pulse Repetition Rate
Useful for determining optical densities for eyewear, filters or windows.

35. CHARACTERISTICS OF LASER LIGHT
MONOCHROMATIC
DIRECTIONAL
COHERENT
Laser light has three characteristics that are different from ordinary light.
The monochromatic property of laser light means it is all one wavelength.
The directional property of laser light means that the beam spreads very slowly.
The coherent property of laser light means that all the light waves are in phase.
From a safety standpoint the most significant result of the characteristics of laser light is that laser light is focused to a very small spot by a lens. Each of the characteristics of laser light reduces the size of the focused spot.
Monochromatic light focuses better than light of many wavelengths.
The more directional a beam is, the smaller the focused spot will be.
Coherent light interferes constructively to intensify the focal spot and make it smaller.
This means that laser light can be concentrated on the retina of the eye by as much as 100 times more than ordinary light. Thus, even relatively low levels of laser light can produce significant eye hazards.
There is no comparison between an ordinary 60 W incandescent bulb and a 60 W laser. The laser will cut thru wood…..
The combination of these three properties makes laser light focus 100 times better than ordinary light
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