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Laser Institute of America

Laser Safety Training © Laser Institute of America1

Laser Safety Officer Training

Section 1

Introduction

2Laser Safety Training © Laser Institute of America

About the LIA

• Founded in 1968

• Based in Orlando, FL

• Staff of 20• Staff of 20

• 800‐345‐2737

• www.lia.org


Laser Safety Officer Training © Laser Institute of America 1

LIA Mission Statement

“The Laser Institute of America is the non‐profit membership society dedicated to fostering lasers laser applications and laser safetylasers, laser applications and laser safety

worldwide”


Industries LIA Serves

• LIA supports, enables & connects all aspects of the laser industry:

– Research & Development

– Manufacturers

– Industrial Users

– Medical Users

– Communications

– Outdoor & Military Users

– Educational Institutions


How LIA Serves the Laser Community

• LIA serves the industry through conferences– International Congress on

Application in Lasers and Electro‐ Optics (ICALEO)

– International Laser SafetyInternational Laser Safety Conference (ILSC)

– Laser Additive Manufacturing Workshop (LAM)

– Lasers for Manufacturing Event (LME)



How LIA Serves the Laser Community

• LIA serves the industry through– Education &

Training Courses– Membership– Publications

• ANSI Standards


American National Standard for Safe Use of Lasers

• Laser Institute of America has been Secretariat and Publisher since 1986

• Responsible for organizing the Consensus Committees


Committees

– industry

– government

– public sectors

Scope of LSO Course

• This course is designed to provide you with the knowledge required to perform the duties of Laser Safety Officer as described in ANSI Z136 1 Safe Use of Lasers standardZ136.1 Safe Use of Lasers standard



Course Objectives

• Upon completion of this course you will know the following:– Laser fundamentals and terminology

– Effects lasers have on the eye and skin

– Understand Hazard Analysis– Understand Hazard Analysis

– ANSI standards and other regulations associated with lasers

– Effects of non‐beam hazards

– Control measures for lasers

– How to set up a laser safety program



Section 2

ANSI and the Laser Safety Officer


What is ANSI?


American

National

Standards

Institute



ANSI

• Over 10,000 approved standards

• U.S. clearinghouse and coordinating body for voluntary standards

id h d f i l• Provide the procedures for creating voluntary standards

• Eliminate duplication of standard activity

• Unifies conflicting standards into one accepted standard


ANSI

• Each standard represents a general agreement between the maker, seller and user ,as to what the best current practice will be in regards to a specific problem.


ANSI

• By reason of Institute procedures, reflects a consensus of manufacturers, consumers, scientific, technical, professional organizations and government agenciesand government agencies

• consensus keeps the bias out of the standard

• ANSI does not review content



ANSI

• Member of:

– International Organization for Standardization (ISO)

– International Electro‐technical Commission (IEC)International Electro technical Commission (IEC)


ANSI Z136

• Prior to 1985, Z136 standards were developed by ANSI Committee Z136 and submitted to ANSI for approval as ANSI Z136 standards

• After 1985 Accredited Standards Committee• After 1985, Accredited Standards Committee (ASC) Z136 was formed

• ASC Z136 responsible for developing laser safety standard


ASC Z136

• Scope of ASC Z136 covers protection against Laser hazards and laser diodes

• Consists of

St d d S b itt (SSC)– Standard Subcommittees (SSC)

– Technical Subcommittees (TSC)

– Editorial Working Group (EWG)



ASC Z136

• Membership to ASC Z136 is voluntary

• Can join through:

– http://www.z136.org/


American National Standardfor Safe Use of Lasers

• Principal U.S. safety standard

• Began in 1969 at request of US. Department of Labor

• April 26, 1973, final document approved

• Revised in 1976, 1980, 1986, 1993, 2000, 2007

• Referred to as ANSI Z136.1‐2007


Purpose of American National Standard for Safe Use of Lasers

• Provides recommendations for the safe use of lasers and laser systems between 180 nm and 1 mm

• Accomplished by classifying lasers and laser systems according to their relative hazards and specifying controls for eachcontrols for each

• Helps determine thresholds where radiant energy becomes a hazard

• Categorizes lasers into four basic hazard classes



ANSI Z136.1: What Type of Standard?

• Z136.1 is a “national consensus standard”

• It is Voluntary

• It is not regulatory nor legally binding


ANSI Z136.1: What Type of Standard?

• To be able to say “our organization is in compliance with” or “conforms with” ANSI Z136.1 means:

– You follow those mandatory requirements that are– You follow those mandatory requirements that are designated “SHALL”

– You take into consideration advisory recommendations designated “SHOULD”

• If they make sense in your application


What is an LSO?



The Laser Safety Officer (LSO)ANSI Z136.1‐2007 Appendix A, page 111

• Individual designated by the employer

• Has the authority and responsibility to monitor and enforce the control of laser hazardslaser hazards

• Shall have the authority to suspend, restrict , or terminate operation of laser system if controls are inadequate


The Laser Safety Officer (LSO)ANSI Z136.1‐2007

• Position may be full or part‐time

• May not be required for Class 1 or 2 lasers

• Required for Class 3B and 4 lasers


Responsibilities of the LSO

• Safety Program

– Establishes and maintains policy and procedures

• Laser system classification (rarely

1

1M

2• Laser system classification (rarely done)

– Shall classify or verify classification


2M

3R

3B

4



• Hazard evaluation– All laser work areas

– Establishment of the Nominal Hazard Zone (NHZ)


laser beam delivery

process

people

environment


• Control Measures—major task

– Compliance with the ANSI standard

– Establishment of alternate control measures

Ensure that those used are working properly– Ensure that those used are working properly



• Procedural Approvals– Standard Operating Procedures (SOPs

for Class 3B & 4 )

– Alignment procedures

– Other ANSI required procedures

P t ti E i t• Protective Equipment– Recommend and approve the

appropriate equipment• Eyewear, clothing, barriers, screens

– Ensure equipment is working properly




• Signs and Labels

• Facility and Equipment–Approve installation facilities and equipmentfacilities and equipment before use

–Approve any modifications to those existing



• Training

– Assure that all personnel receive adequate safety education and training

d l ll• Medical Surveillance

– Shall determine personnel categories



• Records

– Shall keep records required by government regulations

– Shall submit to medical ffi f lofficer names of personnel

working with lasers and medical surveillance schedule

– Training records, audits, SOP approval shall be maintained




• Audits, Surveys and Inspections

– Shall periodically audit by inspection for laser inventory and functionality of all laser safety features and controls for 3B and 4 lasersand 4 lasers

– Shall accompany regulatory agency inspectors (OSHA, CDRH)

– Shall assure corrective action is taken, where required



• Accidents

– Should develop response plan

– Investigation of accidents or incidents



• Approval of Laser Systems Operations (class 3B & 4)

– Only if LSO is satisfied that laser hazard control measures are adequatemeasures are adequate

– Includes Standard Operating Procedures (SOPs)

• Service, maintenance, and operation



LSO & Laser Safety Management

• Without management support no laser safety will exist

• Without someone responsible to see that laser safety is addressed no laser safety willlaser safety is addressed, no laser safety will occur

• A laser safety program does not have to be complex, but does need to exist, at a minimum for regulatory reasons


Where do you find Lasers?


Industry

Drilling



Industry

Marking


Communications

Service providers


Entertainment

Laser light shows



Construction

Surveying

&

Leveling


Military

Direct energy weapon

Targeting

Tracking

Range findingRange finding


Research

Single molecule detection

Spectroscopyp py

Diagnostics

Measurements



Medical

Ophthalmology

• Vision correctionVision correction


Medical

Urology

Cardiology

General surgery


Medical

Dentistry



Medical

Veterinary


Medical

Hair Removal


Medical

Tattoo Removal



Medical

Skin resurfacing


Medical

Port wine stain removal

Vein treatments


Most Common Lasers



What Lasers Don’t Look Like



Section 3

Basic Concepts and Laser Physics


Do I need to be a physicist to understand lasers?


INTERNATIONAL CONSENSUS UNITSSYSTEME INTERNATIONAL (SI) d’UNITES

Fundamental Unit

QuantityMeasured

Common UseWith Lasers


meter [m] length wavelength [�]

kilogram [kg] mass N/A

second [s] time pulse duration


INTERNATIONAL CONSENSUS UNITSSYSTEME INTERNATIONAL (SI) d’UNITES

All other units are derived from these, for example, the following:

Derived Quantity Definition


UnitQ yMeasured Definition

newton [N] force kg∙m/s2

joule [J] energy N∙m = kg∙m2/s2

watt [W] power J/s = kg∙m2/s3

PREFIX SYMBOL MULTIPLICATION FACTOR

exa E 1018

peta P 1015

tera T 1012 Trillion

giga G 109 Billion

mega M 106 Million

kilo k 103 Thousand

hecto h 102

deka da 101

deci d 10‐1 Tenth

centi c 10‐2 Hundredth

milli m 10‐3 Thousandth

micro m 10‐6 Millionth

nano n 10‐9 Billionth

pico p 10‐12 Trillionth

femto f 10‐15 Quadrillionth

atto a 10‐18


Metric and British Lengths

Conversions

1 meter = 40 inches 1 inch = 25.4 mm

1 millimeter = 1 mm = 0.040 inches 0.001 inch = 0.0254 mm = 25.4 m

1 micrometer = 1 m = 1/1000 mm

1 nanometer = 1 nm = 1/1000 m



Radiometric Terms and Units

• Radiant Energy (Q)– energy emitted, transferred, or received in the form of radiation

– Unit: joule[J] 4.186 J = 1 cal

• Radiant Power (�)Radiant Power (�)– power emitted, transferred, or received in the form of radiation

– equal to the radiant energy divided by the corresponding time interval

– also called radiant flux – Unit: watt [W] 1 W = 1 J/s


Radiometric Terms and Units

• Radiant Exposure (H) or energy density– radiant energy striking a surface divided by the area of that surface over which the radiant energy is distributed

– Unit: joules per square centimeter [J/cm2]

I di (E) d it• Irradiance (E) or power density– radiant power striking a surface divided by the area of that surface over which the radiant power is distributed

– radiant exposure divided by the corresponding time interval

– Unit: watts per square centimeter [W/cm2]


Irradiance (E)

1000 watts

Beam diameter 0.01 cm,

Area = 0.000 0785 cm2

Irradiance 13,000,000 W/cm2


Laser

Beam diameter 1 cm,

Area = 0.785 cm2

Irradiance 1300 W/cm2

Beam diameter 10 cm,

Area = 78.5 cm2

Irradiance 13 W/cm2


Wave Motion

• All wave motion can be described in terms of wavelength (l), frequency (f), and wave velocity (v)

• v = f ∙ l

• For light the velocity v = c and

vv

• For light, the velocity v = c and

• c = f ∙ l

• c = 186,000 miles/s

• c = 300,000 km/s


The Electromagnetic Spectrum

Radio Waves

Gamma Rays

a et fra

d owav

es

NonNon--Ionizing RadiationIonizing RadiationIonizing RadiationIonizing Radiation

le L

igh

t


X-Rays

Ult

raV

iole

Inf

Red

Mic

ro

Vis

ib

Optical Radiation

CIE Photobiological Spectral Bands

• UVC: 100 nm to 280 nm (Actinic, Germicidal UV)• UVB: 280 nm to 315 nm (Actinic UV)• UVA: 315 nm to 400 nm (Near UV)• Visible Light: 380‐780 nm (but 400 nm to 700 nm in ANSI*)ANSI )

• IRA: 780 nm to 1400 nm (Near IR)• IRB: 1400 to 3000 nm (Mid IR)• IRC: 3000 nm to 1 mm (Far IR)

• *according to ANSI Z136.1‐2007 visible ranges from 400‐700 nm



Properties of Light

Reflection


Properties of Light :Properties of Light :SpecularSpecular ReflectionsReflections

Specular or mirror-like reflections can occur when the size of surface irregularities or roughness is less than the wavelength of the incident radiation. Angle of incidence angle of reflection


Angle of incidence = angle of reflection Example: A good mirror.

Properties of Light :Properties of Light :Diffuse (Diffuse (LambertianLambertian) Reflections) Reflections

Diffuse reflection occurs when the surface irregularities are randomly orientated and are much greater than the wavelength of the incident radiation.Examples: light reflected from a road


Examples: light reflected from a road surface or tree leaves.


Properties of LightRefraction

Transmission


Properties of Light

• Refraction

– The bending of light

– As light moves from one density medium to a different density medium the light is bentdifferent density medium the light is bent

– Caused by the difference in velocity of light in different mediums – c(v) = 3x108 m/s


Properties of Light

Scattering



Properties of Light

Absorption



What is a laser?

How does it work?



Laser History

Einstein – Theory of Stimulated Emission of Radiation. - 1917

Arthur Schawlow and Charles b l f h


Townes Nobel prize for theory on “Optical Maser” based upon this theory of Stimulated Emission. - 1958

Theodore Maiman invented the 1st Laser – a Ruby Laser - in 1960 based upon Schawlow & Townes theory.

What is a Laser?

Light

Amplification


Stimulated

Emission of

Radiation

Atoms and Molecules

Normalelectron


Ground or Resting State


Photon Absorption & Emission

Excitedelectron

Atom


Atomic electrons can absorb and store energy.

Photon Absorption & EmissionAtom


Stimulates emission of identical photon.



Resonator Cavity

Components of a Laser

Laser Medium

Partially Transmitting Mirror

Totally Reflecting Mirror


Lasing Medium

• CO2

• Argon

Gas

• Krypton


Pulsed Dye – 504nm Pulsed Dye – 585nm Rhodamine Dye

Liquid

Lasing Medium

• Nd:YAG• Erbium:YAG• Erbium Glass• Holmium:YAG

“Solid State” – CrystalsDiode

Holmium:YAG• Ruby• Alexandrite• KTP


Semi - Conductors


Excitation Mechanism

Gas & Semi-conductor:

Electricity or RF


Solid (crystal):

Liquid (dye):

Combination method:

Optical Flash Lamps

DPSS – Laser Stimulated

Characterizing the Laser Output


Characterizing the Laser Output



Repetitively Pulsed Laser Output

• pulse repetition frequency (F or PRF)– measured in Hertz (Hz)– 20 Hz = 20 pulses/s20 Hz 20 pulses/s

• Qp is the energy of a single pulse

• total energy, Q = Qp x number of pulses

• average power, Φa = F x Qp


Monochromatic

Laser vs. NonLaser vs. Non--LaserLaser


Polychromatic

Monochromatic:beams of light are “pure” lines of color

Coherence



Light waves are in phase


mat

ed


No

n -

Col


Col

limllim

ated

Collimation (also referred to as Directional):allows for light to be focused to very small spot sizes

Directional

• Laser beams increase in size (diverge) very little over distance

• A typical laser will “grow” 1 mm every 1 meter traveled (or 1 m in 1 km)

• Such a beam is said to have a 1 milliradiandivergence


What does this have to do with


Laser safety?


Monochromaticity

• Only use laser eye protection specifically labeled for the type of laser usedlaser used

• Just because it is the right color does not mean it will stop the laser


Directionality

• The laser beam can pose a hazard at a considerable distance

• Unlike ionizing radiation, lasers radiation is only hazardous when it is on and when you have line‐of‐sight to the beam


Reflection

Specular


Diffuse


How are Lasers Classified?


Laser Hazard Classification Scheme -ANSI Z136.1

• Class 1 (Exempt)– Incapable of

producing damaging radiation levels during operationE t f – Exempt from any control measure

• Example– Completely enclosed

machine with higher powered laser inside



• Class 1M– Incapable of producing

damaging radiation levels during operation

– Unless the beam is viewed with an optical instrumentp

• Eye‐loupe or telescope

– Exempt from any control measure other than to prevent potentially hazardous optically aided viewing

• Example– Fiber optic communication

systems




• Class 2 (Low power)

– visible (400‐700 nm)

– eye protection is aversion response

– CW upper limit is 1 mW

• Examples

– Supermarket or barcode scanners



• Class 2M– visible (400-700 nm)– eye protection is

aversion response for unaided viewing

– Potentially hazardous Potentially hazardous when viewed with optical aid

– CW upper limit is 1 mW • Examples

– Leveling instruments and some construction industry lasers



• Class 3R– “R” stands for Reduced

Requirements– Potentially hazardous

under some direct and specular reflection

– Eye must be focused and stable

• Probability of injury is small

– Does not pose diffuse‐reflection or fire hazard

– Simply replacing 3a

• Example– Laser pointer




• Class 3B– Operate between

5mW and 500mW– Normally not a fire or

diffuse viewing hazard

– Hazardous under direct and specular reflection viewing

• Examples– Some military lasers,

lasers used in therapeutic medicine, some research lasers



• Class 4– hazardous to eye and

skin from direct viewing, specular and diffuse reflections

– fire hazard– may produce laser y p

generated air contaminants– may produce hazardous

plasma radiation• Examples

– Lasers used for cutting, drilling, marking, welding materials, entertainment and surgical lasers


Class Procedural &

Administrative Controls

Training Medical Surveillance LSO

1 Not Required Not Required Not Required Not Required

1M Required Application Dependent (2)

Application Dependent (2)


2 Not Required (1) Not Required (1) Not Required Not Required

Table 1. Requirements by Laser Classification

2 Not Required (1) Not Required (1) Not Required Not Required

2M Required Application Dependent (2)



3R Not Required (1) Not Required (1) Not Required Not Required (1)

3B Required Required Suggested Required

4 Required Required Suggested Required



Section 4Section 4

Laser Safety Training © Laser Institute of America 1

Beam Hazards:Beam Hazards:Biological Effects Associated Biological Effects Associated

with Laser Usewith Laser Use

What are the Laser What are the Laser Hazards?Hazards?


Laser Brightness (Radiance)Laser Brightness (Radiance)

LARGE FOCAL SPOT(FILAMENT IMAGE)


MICROSCOPICFOCAL SPOT(“DIFFRACTION LIMITED

LENS

LENS


Optical Concentration by the EyeOptical Concentration by the Eye


Wavelengths that focus on retina (400-1400 nm), optical concentration is 100,000 times

Irradiance entering is 1 mW/cm2, at retina will be 100 W/cm2


800 nm trap



The Human EyeThe Human Eye

The Ocular Media - Transparent StructuresNon-scattering - Unlike any other tissue in the body. Why laser surgery was first performed on the eye.


p yAqueous - Water in the anterior chamber

Eye Eye AnatomyAnatomy


Ocular Absorption Site vs. Ocular Absorption Site vs. WavelengthWavelength



Corneal InjuryCorneal Injury

Photokeratoconjunctivitis = Welder’s Flash = Snow Blindness - Produced by photochemical injury of the

Photokeratitis and Corneal Thermal Burns


photochemical injury of the corneal epithelium by ultraviolet radiation (UVB and UVC). Peak of action spectrum is 270 nm.Corneal Thermal Injury -Produced by IR-B and IR-C radiation.

Corneal InjuryCorneal Injury

Ultraviolet Photokerititis

Sunburning of cornea

SuperficialCorneal Burn


Swelling of eye

Corneal Thermal Injury

Most common type of CO2 laser eye injury for E > 10 W/cm2

SevereCorneal Burn




The LensThe Lens

Lens - Provides accommodation, the ability to focus on near objects;very slow metabolic rate and limited ability to repair injury;becomes less pliable with


page, resulting in presbyopia;becomes cloudier with age and eventually opacifies, i.e., a cataract is formed.

Vitreous - A gel; largely water in posterior chamber

14Laser Safety Training © Laser Institute of America 1

CataractCataract

Opacification of the LensCataract - clouding of the lens

Ultraviolet Action Spectrum - Ultraviolet at 300 nm (UV-B).

f d ( ) C d l h


Infrared (Heat) Cataract - Industrial heat cataract common in glassblowers and foundry men at turn-of-the-century. Requires many years of exposure to excessive infrared radiant energy.







The Retina The Retina –– Complex LayersComplex Layers

Lateral Retinal Organization - The retina is not h


homogeneous:Macula Lutea - (“yellow spot”)Fovea Centralis -Central-most area of macula Peripheral Retina - High concentration of rods

The Retina The Retina –– Complex LayersComplex Layers

Neural RetinaNerve tissue which has at least 17 distinct layers

Rods (night vision)


Rods (night vision)

Retinal Pigment EpitheliumTemperature sensitive

Retinal InjuryRetinal Injury

Retinal Thermal Burns –Photodisruption of the

retina


retinaRetinal hemorrhage from Q-switched laser pulse.


Retinal InjuryRetinal Injury

Photodisruption of retina - Retinal hemorrhage from


gQ-switched laser pulse.Visual Effect: Scotoma - Blind spot in field of vision.


Retinal EffectsRetinal Effects

Pupil SizeDetermines the amount of energy entering the eyeTypical Sizes


Typical Sizes2 mm Daylight3 mm Indoor7 mm Dark Adapted8 mm Dilated (for eye exam)


Skin HazardsSkin Hazards


Skin InjurySkin Injury

Thermal Skin Burns

Rare but most


common from CO2 laserUltraviolet Radiation can result in reddening of the skin.

Skin InjurySkin Injury

Most notable injuries


injuriesHoles through fingers3rd degree burns



Beam HazardsBeam Hazards


MPE and Hazard AnalysisMPE and Hazard Analysis

Potential Conditions for Ocular Potential Conditions for Ocular Exposure: Exposure: Intrabeam Intrabeam

ViewingViewingEye is in the direct path of the laser beamThe most serious potential exposure condition



Potential Conditions for Ocular Potential Conditions for Ocular Exposure: Exposure: Specular Specular

ReflectionReflectionEye in the path of a specularly reflected beamAlmost as serious as direct exposure condition


condition

Mirror or shiny surface

Potential Conditions for Ocular Potential Conditions for Ocular Exposure:Exposure: Intrabeam, LensIntrabeam, Lens--onon--

LaserLaser

Eye is in the direct path of the focused laser beamA very serious potential exposure


A very serious potential exposure condition

Potential Conditions for Ocular Potential Conditions for Ocular Exposure: Exposure: Diffuse Diffuse

ReflectionsReflectionsA diffusely reflected portion of the laser beam enters the eye. The least serious potential exposure


condition

α

Angular size (subtense) of apparent source


Maximum Permissible Maximum Permissible Exposure (MPE)Exposure (MPE)

DefinitionThe level of laser

di ti t hi h


radiation to which an unprotected person may be exposed without adverse biological changes in the eye or skin.


MPEs are generally found in Table 5a, page 74 of ANSI Z136.1 (2007).


( )Note “Ocular MPE” means MPE for exposures to the eyeMPEs for skin exposures are found in Table 7, page 77 of ANSI Z136.1 (2007).


Used to determineNominal hazard zone (NHZ)Optical density (OD)Accessible Emission Limit (AEL)




Eye exposure MPE is generally lower than skinDepends on wavelength exposure


Depends on wavelength, exposure duration and other factorsAlso known as Occupational Exposure Limit (EL), Threshold Limit Value (TLV)

Maximum Permissible Exposure Maximum Permissible Exposure (MPE)(MPE)

The Determination of the MPEThe Determination of the MPE

Parameters That Must Be KnownEye or skinWavelength (λ)


Anticipated Duration of ExposureTemporal output

CW or Pulsed?Pulse Width, Pulse Repetition Frequency

Exposure ConditionsFor Retinal Exposure - Point or Extended Source?

Maximum Permissible Exposure Maximum Permissible Exposure (MPE)(MPE)

Anticipated Exposure DurationAnticipated Exposure DurationCW laser

Accidental exposure time is governed by behavioral response


Part of Spectrum Wavelength Range [μm]

Exposure Duration

UltraViolet 0.180 - 0.400 30,000 s

Visible 0.400 - 0.700 0.25 s

InfraRed 0.700 - 1000 10 s


The Determination of the The Determination of the MPE MPE

for Pulsed Lasersfor Pulsed Lasers

Single Pulsepulse width (FWHM)

Repetitively Pulsed


Repetitively Pulsed3 MPEs are compared

single pulse limitaverage power limit

Thermal & Photochemical hazards

multiple pulse MPE for thermal hazards

MPE DeterminationMPE Determination

MPEs are found in Table 5a, page 74 of ANSI Z136 1


of ANSI Z136.1 (2007).Note “Ocular MPE” means MPE for exposures to the eye

Table 5a: Ocular MPE forTable 5a: Ocular MPE forAccidental Exposure, CW COAccidental Exposure, CW CO22

LaserLaser


10.6 μm

MPE = 0.100 W/cm2


MPE Example 1: Ocular Exposure MPE Example 1: Ocular Exposure forfor

CW (Continuous Wave) COCW (Continuous Wave) CO22 laserlaser

2

1 2

J0.996 cmMPE 0.099610 cm

Js

s= =

0.2521

21

JMPE (0.56)(10) cmJMPE (0.56)(1.778)

=

=


2 21W WMPE 0.0996 0.1cm cm= =

For a CW laser, power (watts) is energy (joules) divided by time (seconds).

21

21

MPE (0.56)(1.778) cmJMPE 0.996 cm=

Either way, we find MPE = 0.100 W/cm2.

The Nominal Hazard Zone, NHZThe Nominal Hazard Zone, NHZ

The NHZ is the space within which the level of direct, reflected or scattered laser light exceeds the MPE level for the laser.Si il l f fl ti th


Similarly, for reflections, the potential beam exposure decreases with distance.At some distance, the irradiance is less than the MPEE.That “boundary” defines the NHZ.

Nominal Hazard Zone Nominal Hazard Zone for CW 2000 watt COfor CW 2000 watt CO22 LaserLaser

Beam could exit through opening ( i t l k d)


(non-interlocked)

Bending mirror must be removed for cleaning or alignment


Nominal Hazard Zone for CW 2000 watt Nominal Hazard Zone for CW 2000 watt COCO22 LaserLaser

Case 1: Case 1: IntrabeamIntrabeam ExposureExposure


INTRABEAM*

*From page 125 of ANSI Z136.1 (2000), page 193 ANSI Z136.1(2007)




Emergent Beam Diameter (a) = 1.0 cmBeam DivergenceAverage Power

Assumed laser properties:

watts 2000Φ=

ns0.004radia4mrad==φ

21

21.0π(0.100)4(2000)

0.0041rNOHD ⎥

⎦

⎤⎢⎣

⎡−=

[ ] 21

NOHD 125,465250r −=

39,900cm250(160)rNOHD ==

0.248miles1310feet399mrNOHD ===



Eye and Skin Hazard for 1310 feet!


Bending mirror, removed for cleaning or alignment



Case 2: LensCase 2: Lens--onon--Laser ExposureLaser Exposure


LENS-ON-LASER*From page 125 of ANSI Z136.1 (2000), page 193 ANSI Z136.1(2007)




Average Power: Φ = 2000 watts

Focal length of optics: ƒo = 127 mm

Beam diameter at focusing optics: bo = 31mm

Emergent Beam Diameter (a) = 1.0 cm

Assumed laser properties:2

1

NOHD π(0.100)4(2000)

31127r ⎥

⎦

⎤⎢⎣

⎡=

[ ] 21

NOHD 25,4654.10r =

21.5feet654cmrNOHD ==



NHZ = 21.5 ft

Lens-on-Laser hazard may not be realistic



ρ

Specular Reflection from the workpiece simply folds the beam backwards from here.


Case 3: LensCase 3: Lens--onon--Laser, Laser, SpecularSpecular Reflection Reflection ExposureExposure

ρ


Specular Reflectivity of workpiece ρ=20% = 0.20

Beam diameter at focusing optics bo = 31 mm

Focal length of optics: ƒo = 127mm


1

NOHD π(0.100)20)4(2000)(0.

31127r ⎥

⎦

⎤⎢⎣

⎡⎥⎦

⎤⎢⎣

⎡=

21)5093)(10.4(=

)4.71)(10.4(=

feetcmrNOHD 6.9293 ==

Average Power: Φ = 2000 watts

Nominal Hazard Zone for CW 2000 Nominal Hazard Zone for CW 2000 watt COwatt CO22 Laser, Case 3: LensLaser, Case 3: Lens--onon--

Laser, Specular Reflection ExposureLaser, Specular Reflection Exposure

9.6 Feet!

SpecularReflection from workpiece may


workpiece may be blocked by laser head

Nominal Hazard Zone for CW Nominal Hazard Zone for CW 2000 watt CO2000 watt CO22 Laser Case 4: Laser Case 4:

Diffuse Reflection ExposureDiffuse Reflection Exposure


DIFFUSE REFLECTION*From page 126 of ANSI Z136.1 (2000), page 194 ANSI Z136.1(2007)


Nominal Hazard Zone for CW 2000 Nominal Hazard Zone for CW 2000 watt COwatt CO22 Laser Case 4: Diffuse Laser Case 4: Diffuse

Reflection ExposureReflection Exposure


Power (F ) = 2000 watts

Reflection Coefficient ρ = 100% = 1.0


1

)1.0()0.1)(2000)(0.1(⎥⎦

⎤⎢⎣

⎡=

πNHZr

cmrNHZ 8.79)6366( 21==

inchesrNHZ 31=

Viewing angle θ = 0 , (cos 0) = 1.0

Nominal Hazard Zone for CW 2000 Nominal Hazard Zone for CW 2000 watt COwatt CO22 Laser, Case 4: Diffuse Laser, Case 4: Diffuse

Reflection ExposureReflection Exposure

31 inches


inches

It is sometimesunlikely that an operator could be within the diffuse reflection hazard zone.

What is Optical Density?What is Optical Density?



Laser Eye Protection Laser Eye Protection ––Optical Optical Density D(Density D(λλ))

OD is the base 10 logarithm of the attenuation factor associated with the filtration mediumAttenuation factor is the ratio of the laser


beam irradiance striking the filter divided by the irradiance transmitted by the filter

Laser Eye Protection Laser Eye Protection ––Optical Optical Density D(Density D(λλ))

OD = D(λ) describes ability of filter to attenuate optical radiation at a

incident

incidentEEOD 10log=

BeamAreaLaserPowerEincident=


to attenuate optical radiation at a particular wavelengthCan use ratios of power, irradiance, or radiant exposure, but must be compatibleEtransmitted = MPE (usually)OD is a dimensionless number

Optical Density ODOptical Density OD

OD Attenuation Transmission

1 10 0.1

2 100 0.01


3 1,000 0.001

4 10,000 0.0001

5 100,000 0.00001

6 1,000,000 0.000001


Section 5Section 5NonNon--beam Hazardsbeam Hazards


Hazards Associated with laser Hazards Associated with laser useuse

NonNon--Beam HazardsBeam Hazards

Are a class of hazards that do not result from direct human exposure to a laser beam (Sec 7.1)In some cases can be life threatening


gelectrocution

NonNon--Beam HazardsBeam Hazards

Occur subsequent toExposure of a material to a laser beam

Example is a beam induced fire

Components of a laser system


Example is exposure to a capacitorMaterials used to generate laser beam

Example is gases, dyes and solventsHow and where a laser system is used

Example mechanical hazard or limited space


NonNon--Beam Hazards & Beam Hazards & ANSI Z136.1ANSI Z136.1--2007, Section 72007, Section 7

“Non-Beam Hazards”section provides guidance on:

Electrical hazards (Sec. 7.2.1)Laser generated airborne contaminants (Sec. 7.3.1)Collateral and plasma radiation (Sec. 7.2.2)


Collateral and plasma radiation (Sec. 7.2.2)Fire hazards (Sec. 7.2.3)Explosion hazards (Sec. 7.2.4)Compressed gases (Sec. 7.3.2)Laser dyes (Sec. 7.3.3)Robotics-associated mechanical hazards (Sec. 7.2.5) Noise (Sec 7.2.6)Waste disposal (Sec 7.5.4)Ergonomics (Sec. 7.5.1)

Electrical AccidentsElectrical Accidents

Electrocution: 5th leading cause of work related injury/death in


U.S.Electrocution: one cause of laser-related death2nd most often reported cause of laser accidents

Electrical InjuriesElectrical Injuries

Result from current flow through tissuesMay be thermal due to proximity to arcs or overheated components


Factors determining extent include:Body impedance: skin resistance (moisture content, abrasions/cuts)Path through body: arm-to-arm includes major organsBody sizeCurrent magnitude and frequency


Quantitative Effects of Electric Current on Humans Quantitative Effects of Electric Current on Humans (Current in (Current in mAmA))

Effect DC DCAC 60 Hz

AC 60 Hz

AC 10

kHz

AC 10

kHz

Men Women Men Women Men Wome

n

Slight Sensation on Hand 1 0.5 0.4 0.3 7 5

Perception threshold, median 5.2 3.5 1.1 0.7 12 8


Shock-not painful and muscle control not lost 9 6 1.8 1.2 17 11

Painful Shock-muscular control lost by ½% 62 41 9 6 55 37

Painful Shock-let go threshold, median 76 51 16 10.5 75 50

Painful, severe shock-breathing difficult, muscle control lost by 99% 90 60 23 15 94 63

Possible ventricular fibrillation-three-second shocks 500 500 100 100

Possible ventricular fibrillation-short shocks (T in sec) 165√T 165√T

Possible ventricular fibrillation-high voltage surges 50* 50* 13.6* 13.6*

*These values are energy in watt-seconds, all other values are in milliampres. “T” is time in seconds.Note: Adapted from Dalziel

Capacitor ExposureCapacitor Exposure

Potential for:Accumulation of residual charge after equipment is deenergizedHeating and explosion with high current flow


Explosion from capacitor’s internal failureArcing at contact point for internal failure

Arc BurnArc Burn



Electrical Hazards Control Electrical Hazards Control --CapacitorsCapacitors

Restrict access until capacitors are discharged, shorted, and groundedConsider capacitor cases “Hot”Store capacitors shorted


Store capacitors shortedVerify automatic discharge devicesConduct manual shorting - don’t trust auto-discharge

Electrical Hazards Controls Electrical Hazards Controls ––Work PracticesWork Practices

Work on deenergized parts of electrical systemsUse insulated tools Use insulating blankets & covers as


Use insulating blankets & covers as applicableDon’t wear highly conductive items on hands or arms


Follow the one-hand rule when probing or measuring; eliminate arm-to-arm pathwayUse test equipment

t d f t lt


rated for system voltageEnsure the circuit you switch off is the proper oneMove any obstacles that restrict working clearance



Don’t work alone; your “buddy” must know first aid/CPR/automatic external defibrillator (AED) useFollow all safety procedures, including


y p , glockout/tagout: 29 CFR 1910.147safety-related work practices: 29 CFR 1910.331 – 335local, written procedures

Electrical Hazards Controls Electrical Hazards Controls --PPEPPE

Wear safety glassesUse insulating (rubber) gloves & arm covers as


arm covers as applicableWear “flash suit” for high-voltage work

NFPA 70E StandardTested according to ASTM F-1506

Laser Generated Air Laser Generated Air Contaminants (LGAC) Sec Contaminants (LGAC) Sec

7.3.17.3.1Generated when class 3b or 4 laser beams interact with matterLGAC d d


LGAC depends upon target material, cover gas and beam irradianceDifficult to predict what LGAC is released into air


Laser Generated Air Laser Generated Air Contaminants (LGAC)Contaminants (LGAC)

When target irradiance reaches 107 W·cm-2

Target materials may liberate carcinogenic, toxic and noxious airborne contaminants (table F1(a), appendix F)


F1(a), appendix F)LGAC released may be gaseous or particulate (see table F1(b))LSOs responsibility to ensure that any IH issue be addressed and he/she may consult with Industrial Hygienist

Laser Generated Air Laser Generated Air Contaminants (LGAC) Contaminants (LGAC)

AerosolsAerosols

Types: dust, mist, fume, smoke, fog, smog


smogInterests: composition, size, distribution, concentration

Laser Generated Air Contaminants Laser Generated Air Contaminants (LGAC)(LGAC)

Laser Cutting of TissuesLaser Cutting of TissuesNIOSH Study

CO2 and Nd:YAG LasersLab evaluation using beef liverSimilar gaseous by-


productsbenzenetoluenexylenesformaldehydeacetalaldehydeacroleinvarious PAHs


Laser Generated Air Contaminants Laser Generated Air Contaminants (LGAC) (LGAC) Workplace Studies on Workplace Studies on

tissuetissue

NIOSH evaluated operating rooms, laser clinics, animal labs, and an experimental


and an experimental laser labGaseous by-products

formaldehydealcoholscyanidevarious hydrocarbonsPAHs

Laser Generated Air Laser Generated Air Contaminants (LGAC) Contaminants (LGAC)

MicroorganismsMicroorganisms

Viral: HIV DNA, viable bacteriophage, human and bovine papillomavirusBacteria: Staphylococcus auerus,


Bacteria: Staphylococcus auerus, Escherchia coliSee Table F1(b), pp. 230-233, ANSI Z136.1-2007

Biological Agents:Biological Agents:Control MeasuresControl Measures

Smoke evacuation equipmentSurgical MasksProtective Clothing


Protective ClothingEye Protection


Laser Generated Air Contaminants Laser Generated Air Contaminants (LGAC)(LGAC)

Control measuresExhaust ventilation

Hoods, ducts, air cleaners, and fansComply with latest version of Industrial Ventilation & Fundamentals Governing the Design & Operation of Local


Design & Operation of Local Exhaust Systems (ANSI Z9.2)

Respiratory protectionUsed to control brief exposure or as interim control until engineering control are put in placeCompliance with OSHA (29CFR 1910.134)

Laser Generated Air Laser Generated Air Contaminants (LGAC)Contaminants (LGAC)

Control measuresProcess Isolation

Surround process with barrier, remote control devices, robotic manipulatorsEspecially when laser welding or cutting of materials


Especially when laser welding or cutting of materials such as plastics, biological material, composite substrates

Collateral and Plasma Collateral and Plasma RadiationRadiation

(Sec 7.2.2.1)(Sec 7.2.2.1)

Collateral is radiation other than that associated with


that associated with the primary laser beamPlasma radiation is a result of a laser beam interacting with matter


XX--RadiationRadiation

BremsstrahlungGerman for “braking radiation”

Requirements for bremsstrahlungSource of electronsHi h lt l


High-voltage supply“Target” for electrons to interact with

Possible sources with laser systemsthyratron switches in pulsed lasersfree electron lasers

Ultraviolet RadiationUltraviolet Radiation

Discharge tubes


tubesPlasma tubes: Nd:YAG & CO2

BlueBlue--Light Hazard RegionLight Hazard RegionBroadband Irradiance ~ 400 to 550 nmBroadband Irradiance ~ 400 to 550 nm

Flash lamps


Arc lampsOptical pumping


RadioRadio--Frequency Fields:Frequency Fields:

Sealed plasma-tube CO2 lasers


tube CO2 lasersPulse-forming components in Pulsed lasers

Plasma Radiation examplePlasma Radiation example

IR beam interacts with t i l t l


stainless steelSmall spot of light is visible beneath nozzleBright and rich in blue wavelengths

Fire Hazards Fire Hazards –– Ignition Ignition SourcesSources

Laser beamANSI Z136.1 – 10 W/cm2 (CW)NFPA 115 – 0.5 W/cm2 (CW)EN 50821 - > 35 mW & 5 mW/mm2 (CW, dust)


> 0.1 mJ/mm2 for 5 sec (pulsed, dust)

System electrical components


Fire Hazards Fire Hazards –– Combustible Combustible MaterialsMaterials

Enclosure materialsConstruction


Construction materialsTarget materialsLaser GasesSolvent vaporsLGAC

Explosion HazardsExplosion Hazards

May exist within laser, due to:high pressure arc lampsfilament lampscapacitor banks


capacitor banksMay exist outside the laser, due to:

the target (flying particles)elements of the optical train, which may overheatDust explosion in ventilation system

MetalMetal--Dust ExplosionDust Explosion

Explosions in a dust collector (needed service)400 W, Nd:YAG used to drill holes in jet engine turbine blades


gDrilling liberated ~ 1 lb Ni and Co dust per dayDeposited Ni/Co in 75k ft2 of buildingTook asbestos abatement crew 4 days to clean facility


Compressed GasCompressed Gas

Missiles


waiting to blast off!

Laser Dyes and SolventsLaser Dyes and Solvents

Tunable lasersRequires dissolution of


dissolution of organic powder in an organic solventArgon laser used as energy pump


Solution reservoir, pump, recirculating lines


No secondary containmentLocation: possible trip hazard leading to spills



Dyes: complex organic compoundsDyes: some are toxic and/or mutagenic; little is known about manySolvents: organic compounds


Solvents: organic compoundsSolvents: may be irritants, anesthetics, and/or absorbable through skinSolvents may be flammable


Dyes: highest exposure potential is during preparationSpills: exposure potential to both dyes and solventsL Di bl t ti l f


Laser Disassembly: potential for contaminated partsUser has to deal with hazardous waste, cannot dump down sink

Laser Dyes and Solvents:Laser Dyes and Solvents:Spilling Chemicals on Spilling Chemicals on

Clothing/SkinClothing/Skin

Go immediately to safety


yshower/eyewashRemove clothing and flush/rinse with waterWhy?


NonNon--Beam Hazards:Beam Hazards:CategoriesCategories

ChemicalBiologicalPhysical


PhysicalHuman Factors

NonNon--Beam Hazard:Beam Hazard:Chemical AgentsChemical Agents

Laser-generated air


contaminants (LGAC)Compressed GasesDyes/Solvents

NonNon--Beam Hazard:Beam Hazard:Biological AgentsBiological Agents

Laser generated air contaminants


contaminants (LGAC)MicroorganismsInfectious material


NonNon--Beam Hazard:Beam Hazard:Physical AgentsPhysical Agents

ElectricalCollateral & Plasma RadiationFire


Fire ExplosionMechanical/RoboticNoise

NonNon--Beam Hazard:Beam Hazard:Human FactorsHuman Factors

ErgonomicsLimited work space


pWork patternsLaser & laser waste disposalChillers


Section 6Section 6


Laser AccidentsLaser Accidents

Laser Accidents & IncidentsLaser Accidents & Incidents

Accident – an unforeseen and unplanned event or circumstance

Thinking the alignment complete, the student removed eyewear and walked into the path of t b


a stray beam.

Laser Accidents & IncidentsLaser Accidents & Incidents

Incident – an action likely to lead to grave consequence

Based upon a dare, the teenager held open an eyelid and stared into the beam


p yof the laser pointer, although it was very uncomfortable.


Laser Accidents and IncidentsLaser Accidents and Incidents

Beam scenarioseye exposure: temporary/permanent vision lossskin exposure: burns or photochemical effects

Non beam scenarios


Non-beam scenariosshock/electrocutionexposure to chemical agentsignition of flammables/combustibles

Laser Accidents & Incidents: Laser Accidents & Incidents: Overview 1999Overview 1999

Top 5 lasers: Nd:YAG, Ar, CO2, dye, diodeBreakdown of incidents

71% - eye injury 16 9%

Eye

Skin

Non-beam


71% eye injury11.9% - skin injury16.9% - non-beam incident

Data from Rockwell, RJ, ILSC 99 Proceedings, LIA

71%11.9%

16.9%

Laser Accidents:Laser Accidents:Personnel Exposure SummaryPersonnel Exposure Summary

Accident Data Summary: Division of 395 events: 1964-1998

Technicians Exposed (81): 20.5%Scientists Exposed (78): 19.8%Students Exposed (46): 11.6%

Patients Exposed (40): 10.1%


Patients Exposed (40): 10.1%Plant Workers Exposed (35): 8.9%Dr.s & Nurses Exposed (26): 6.6%Pilots & Military Exposed (26): 6.6%Spectators Exposed (25): 6.3%Laser Show Operators Exposed (11): 2.8%Equipment only damaged (10): 2.5%Field Service Exposed (10): 2.5%Office Staff (uninvolved) (7): 1.8%

Data from Rockwell, RJ, ILSC 99 Proceedings, LIA


Laser Incidents: Laser Incidents: Eye Eye InjuryInjury

>70% of all incidents82.3% of severe eye injury caused by Nd:YAG, Ar, dye, ruby, dbl-Nd:YAG and


y , y,Ti:SapphireLaser light shows have resulted in transient effects (e.g., flash blindness) to airplane pilots

Laser Incidents: Laser Incidents: Eyewear Eyewear ConcernsConcerns

Not using eyewear (may have been available)Eyewear failure


yImproper eyewearImproper fit

Laser Accidents:Laser Accidents:Skin InjurySkin Injury

CO2 laser –Entry point


CO2 laser most often implicated

Exit point


Laser Accidents:Laser Accidents:FireFire

CO2 > Nd:YAG, dyeBeam: CO2 and Nd:YAG


Nd:YAGClothing: e.g., tiesSolvents: dyeMajor cause of death in medical settings

Laser Accidents: Laser Accidents: DeathDeath

Blood loss (9)Embolism (7)Electrocution (5)Endotracheal tube


Endotracheal tube fires (3)Skin loss (1)

From: Johnson & Wartick, ILSC 2003 Conf. Proc. Prog.

Laser Accidents:Laser Accidents:Most Hazardous ActMost Hazardous Act


Act of adjusting the optics in the beam path in relation to each other so the beam will propagate in some pre-determined manner; may be internal to laser or external.


Laser Accidents:Laser Accidents:AlignmentAlignment

Estimates ~1/3 of all (known) accidents~60-70% of all (k ) l b


(known) laboratory accidents

Common scenario: unanticipated reflection from an optic while not wearing protective eyewear

Laser Accidents:Laser Accidents:AlignmentAlignment

Optics or devices involved in reflections of errant / stray beams:

Prisms Brewster


Prisms, Brewster windows, frequency doubling crystals, blade, color center crystal, chrome objective, polarizers, dye cell windowsTargets: chalk, photographic paper, test paperEnergy meter detector

Laser Accidents:Laser Accidents:Hazardous Acts Hazardous Acts –– Beam AlignmentBeam Alignment

Wearing inappropriate eyewearWavelength compatibility problem, especially for multiple wavelengths



Laser Accidents:Laser Accidents:Hazardous Acts Hazardous Acts –– Beam AlignmentBeam Alignment

Turning to look at source of bright light detected by peripheral visionElevating (vertical) beams – aim it at your


faceNot determining location of stray / errant beamsPoor communication between co-workers

Laser Incident Makes Laser Incident Makes Headlines!Headlines!


Laser Accidents:Laser Accidents:IIncident from CDRH databasencident from CDRH database

MAUDE DB Iris medical slit lamp report number 2939653-1999-00002752959 patient sequence number: on May 5, 1999, a sales rep demonstrated an iris medical occu-light glass laser system with a slit lamp adapter delivery device to three Drs at the hosp. While making practice burns on a business card, Dr 2 commented on the brightness through the oculars after test firing the laser. Dr 2 and 3 said they saw "spots" after test firing; Dr 1 and the sales rep


said they saw "spots" after test firing; Dr 1 and the sales rep noticed no unusual brightness. Upon further inspection of the slit lamp adapter delivery device, it was noticed that the safety filter frame was labeled 810 nm. The wavelength of the laser being demonstrated was 532nm. On May 6, 1999, it was verbally reported by the hospital risk manager to the sales rep, that Dr 3 was found to have 20/50 vision and three suspected laser burns on his retina. The ophthalmologist who examined Dr 3 indicated that it may take several months for the vision to recover/stabilize.


Laser Accidents:Laser Accidents:Incident at Federal Laboratory: The Incident at Federal Laboratory: The

set upset up



set upset up



set upset up



Laser Accidents:Laser Accidents:By passBy pass


How prepared are you and your How prepared are you and your institution for a laser accident?institution for a laser accident?

Does staff know who to call?Does staff know the number to call?Will the receiver of the call know how to respond?


respond?If you have a medical staff, can they recognize a laser injury?Do they know how to treat one?

SUSPECTED EYE INJURYThe following action is to be taken:

1. Determine if any local assistance is

IN CASE OF LASER IN CASE OF LASER ACCIDENTACCIDENT


1. Determine if any local assistance is available, such as a co-worker: If yes, have them follow steps 2 & 3.If not, call for assistance, do not go by yourself!2. Keep the person as Calm as possible3. Call Medical/Fire dept, ext. ////////


Regular hours: you can transport person to Medical

Off hours: Fire Dept to provide transportation

4 Notify Laser Safety officer

SUSPECTED EYE INJURYSUSPECTED EYE INJURYThe following action is to be takenThe following action is to be taken


4. Notify Laser Safety officer. Off hours number?

5. Notify supervisor.

6. Work needs to stop until an evaluation is conducted to see if a systematic error or hazard

exists.

SUSPECTED SKIN INJURYSUSPECTED SKIN INJURY

1. Keep person calm.2. Call Medical /Fire Dept3. Follow steps as for eye injury4. If hand burn with no active bleeding, you

can transport yourself to medical


p y

Background:At the scene, reassurance is the most important thing

one can provideNot all laser injuries have an immediate effect on

vision, an initial and a follow-up eye examination are critical

Let others know what happenedWork needs to stop until an evaluation is conducted to

see if a systematic error or hazard exists

Your community may have limited choices on Your community may have limited choices on where to send an individual with a laser eye where to send an individual with a laser eye

injury.injury.It is important that the facility have some understanding of laser eye injuries. Once the individual informs the medical staff they work with or around lasers, any injury, in particular retinal, will be assumed to be laser induced.


Medical might overlook the fact that many other optical sources or diseases could be the reason for visual problems or defects in the eye. Provide the name of a retinal specialist to the individual for further evaluation or follow up, particularly in cases involving visible or near infrared laser radiation.


Accident InvestigationAccident Investigation

Has many componentsAccident investigation teamMembersHow to interview


Who result should be told toPersonnel issuesThe accident scene

Do not forget Do not forget -- Lessons Lessons Learned NoticeLearned Notice

Once the fact of the incident are understood a Lessons Learned notice should be written and distributed to the institution's laser community


This notice should not be a document to blame someone for the incident, but rather to point but the contributing factors and how the incident can be prevent from happening in the future


Section 7Section 7


Laser Regulations and Consensus Standards

Laser Safety Standards: USLaser Safety Standards: US

ANSI Z136.1-2007 for Safe Use of LasersZ136.2-1997 for Safe Use of Optical Fiber Communication Systems Utilizing Laser Diode and LED Sources

DOES NOT EXIST W d i i t ti l


DOES NOT EXIST-Was administratively withdrawn

ANSI Z136.3-2005 for Safe Use of Lasers in Health Care Facilities

Laser Safety Standards: US Laser Safety Standards: US (cont’d)(cont’d)

ANSI Z136.4-2005 RP for Laser Safety Measurements, Hazard Evaluation, and InstrumentationANSI Z136.5-2000 for Safe Use of Lasers in


S 36 5 000 o Sa e Use o ase sEducational InstitutionsANSI Z136.6-2005 for Safe Use of Lasers OutdoorsDraft Z136.7-200x for Certification & Testing of Laser Eyewear and Barriers


Other ANSI Standards in the Other ANSI Standards in the WorksWorks

Safe Use of Lasers in Research, Development & TrainingSafe Use of Lasers in Manufacturing EnvironmentsS f U f L i E t t i t


Safe Use of Lasers in Entertainment, Displays and Exhibitions

Laser Regulations: FDALaser Regulations: FDA

21 CFR Subchapter J – Federal Laser Product Performance Standard (FLPPS)

Applies to laser product manufacturers and those modifying laser products

Selling in US


gLegally binding

Requires certification of laser products, and 1st step is classification

http://www.fda.gov/cdrh/radhealth/products/lasers.html

CDRH Federal Laser Product CDRH Federal Laser Product Performance StandardPerformance Standard

Basic Principle: Radiation must be eliminated or safely contained except


where and when access is necessary to provide function.



FDA does not consider a product to have been “manufactured” if it is constructed on a one time basis by a particular


on a one time basis, by a particular company, for use in its manufacturing process at the place where constructed.


FDA will not consider multiple products to have been “manufactured” provided they

are not shipped in interstate commerce


are used solely at the place where constructedare used by the same employees who constructed themare not made on a recurring basis

Laser and Laser System Laser and Laser System Engineering RequirementsEngineering Requirements

All lasers must have:Protective Housing

Safety interlocked to prevent access to laser radiation

Key Control


Key ControlLaser Emission IndicatorManual Reset


Labeling Requirements of the Labeling Requirements of the CDRH StandardCDRH Standard

All lasers must have:Certification labelIdentification labelName and address of

f t


manufacturerPlace, month, and year of manufactureHazard classificationRadiation output info and warning logotypeAperture label

User Informational User Informational RequirementsRequirements

Adequate instructions for assembly, operation, and maintenance, including clear warnings concerning precautions to avoid exposure to laser radiation in excess of the applicable emission limits, and schedule of maintenance necessary to


, ykeep the product in compliance.A statement of the magnitude, in appropriate units, of the pulse duration, maximum radiant power, and, where applicable, the maximum radiant energy per pulse.

Modification of a Certified Modification of a Certified ProductProduct

The modification of a laser product, previously certified under 21CFR1040, shall be construed as manufacturing under the Act if the modification affects any aspect of the product’s performance or intended function for which this section


or intended function for which this section (1040.10) has an applicable requirement. The manufacturer who performs such modification shall recertify and re-identify the product in accordance with the provisions of 21CFR1010.2and 21CFR1010.3.


Acts Prohibited by the CDRH Acts Prohibited by the CDRH StandardStandard

Sale of noncompliant productsFailure to notifyF il t t bli h d i t i d


Failure to establish and maintain recordsFailure to certify; false certification

Penalties Specified by the Penalties Specified by the CDRH StandardCDRH Standard

$1000 per violation$330,000 per series of violationsCan apply to any person or firm


What is CDRH Laser Notice No. What is CDRH Laser Notice No. 50?50?

CDRH Laser Notice No. 50 permits manufacturers to classify their products


classify their products in accordance with IEC 60825-1The LSO will see more and more products certified to meet IEC 60825-1


International Laser Safety International Laser Safety StandardsStandards

International Electrotechnical Commission (IEC)IEC 60825-1, for the Safety of Laser ProductsIEC 60825-2, for the Safety of Fiber Optic SystemsAdopted as EN 60825-1 & EN 60825-2

International Commission on Non-Ionizing


International Commission on Non Ionizing Radiation Protection (ICNIRP)

Recommends exposure limits for laser radiationPosition statements: laser pointers & LEDs/laser diodes

International Standard International Standard –– IEC IEC 6082560825--11

Latest edition: 2007Used in most countries outside the USImportant for laser


Important for laser product export by US manufacturersLEDs have been dropped–like all US standards and regulations

How Do I Recognize a Laser Product How Do I Recognize a Laser Product Certified to Meet the International Certified to Meet the International

Standard?Standard?

Look for the certification label or explanatory label


explanatory labelUse of new classifications such as 3R, 1M or 2MAppearance of the international laser safety logo (at right)


OSHAOSHA

29 CFR 1910: Standards for General Industry

Main body of regulationsDoes not use the word laser in these standards


29 CFR 1926: Standards for Construction Industry

Mentions laser in section on PPE

CFR = Code of Federal Regulations

OSHAOSHA

Construction Industry Standard (29 CFR 1926)

29 CFR 1926.54 – non-ionizing radiation


General Industry Standard29 CFR 1910.132 – general requirements for PPE29 CFR 1910.133 – eye and face protection29 CFR 1910.134 – respiratory protection29 CFR 1910.147 – lock out/tag out

OSHAOSHA

Limited regulations specific to lasersInspectors may cite Z136.1 under General Duty Clause – Public Law 91-596May utilize other standards applicable to


May utilize other standards applicable to laser safetywww.osha.gov/SLTC/laserhazards/index.html


General Duty ClauseGeneral Duty ClauseMichigan 2005: “The employer did not furnish employment and a place of employment which were free from recognized hazards that were causing or likely to cause death or serious physical harm to employees in that employees were exposed to the hazards of infrared non-ionizing radiation capable of causing severe burns


ionizing radiation capable of causing severe burns of the eyes and skin. Specifically, class IV, metal cutting lasers (1800 watts, carbon dioxide, wavelength 10600 nm)…”

“Facility using high powered CO2 laser for cutting metal products. Employees were using standard safety glasses and there was no guarding at and near where the laser was cutting metal. The company did not provide a laser safety program or have a laser safety officer at the time of investigation.”

General Duty ClauseGeneral Duty Clause

Citation specifies:No written SOPs to ensure that operators and nearby employees area not excessively exposed to non-ionizing radiation.N LSO d ti d t i i t l


No LSO, education and training, control measures, medical surveillance program.$500 monetary penalty, 30 days to fix

General Duty ClauseGeneral Duty Clause

Recommendation: “One feasible method of compliance is to conform to the


conform to the requirements of the American National Standards Institute Publication, ANSI Z136.1-2000.”


OSHA Web ResourcesOSHA Web Resources

Safety and Health TopicsLaser Hazards

http://www.osha.gov/SLTC/laserhazards/index.html

f


Laser Institute of Americahttp://www.osha.gov/dcsp/alliances/lia/lia.htmlhttp://www.laserinstitute.org

Laser Guidelines: Federal Laser Guidelines: Federal Aviation Administration Aviation Administration -- FAAFAA

FAA 7400.2DOutdoor laser/high intensity light demonstrations


Guidance document “for determining or verifying the effects…on the safe and efficient utilization of airspace”Enforcement by Federal Marshals

Laser Regulations: Various Laser Regulations: Various States & MunicipalitiesStates & Municipalities

Comprehensive regulations: Alaska, Arizona, Arkansas, Florida, Illinois, Georgia, Massachusetts, New York, Texas, WashingtonLaser pointer regulations (pending & adopted):


Laser pointer regulations (pending & adopted): Arkansas, California, Hawaii, Kansas, Illinois, Maine, Maryland, Massachusetts, Michigan, New Jersey, New York, North Carolina, Rhode Island, Tennessee, Texas, Virginia, and WashingtonLocal ordinances restrict purchase of laser pointers by minors and/or restrict use


Regulations & Regulations & Consensus StandardsConsensus Standards

Canada


RegulationsRegulations

Radiation Emitting Devices Act (RED)Chapter R-1:2001issued by Department of Justice Canada RED refers to both 21CFR and IEC 60825 as the prescribed regulations for product safety

Depending on Canadian province and local Canadian authority having jurisdiction, either 21CFR or IEC 60825 compliance is required for laser products sold Canada



Radiation Emitting Devices Act (RED)Applies to Manufacturers, distributors, lessors and importers of radiation emitting devices, including:

Laser scannersLaser scannersDemonstration lasers

Radiation Emitting Devices (RED) Actgoverns the sale, lease and import of certain radiation emitting devices used for medical and industrial purposes or by consumers.




RED sets safety performance standards for the sale, lease, import, labelling, packaging, and advertising of radiation emitting devices to ensure that workers and the public are not placed at risk and the public are not placed at risk. Manufacturers and importers are required to notify the Minister of Health Canada if a device does not comply with the regulations or creates a risk to any person.



The Consumer and Clinical Radiation Protection Bureau (CCRPB)

Agency of Health Canadaassesses, monitors and assists in the ,reduction of the health and safety risks associated with radiation emitting devices and other sources of radiationLasers must be reported to CCRPB



Canada Occupational Health and Safety Regulations

Lasers are covered under the Canadian LabourCode

Part 10 HAZARDOUS SUBSTANCES Section 10.26 Ionizing and Non-ionizing Radiation Laser Scanners, demonstration lasers, Lasers must be reported to the Consumer and Clinical Radiation Protection Bureau of the Department of Health



StandardsStandards

Canadian Centre for Occupational Health and Safety (CCOHS)

Provide guidance for lasers in health care facilities.h // h / h / h /lhttp://www.ccohs.com/oshanswers/phys_agents/lasers.html

The Canadian Standards Association (CSA) Standard CAN/CSA-Z386-01: Laser Safety in Health Care Facilities



Section 8Section 8


Laser Safety Control Measures

Purpose of Control MeasuresPurpose of Control Measures

Reduce exposure to laser radiation to non-hazardous levels (< MPE)

In some cases, we may want to reduce b th l l th t


exposure beneath levels that cause transient effects (e.g., flash blindness or afterimage)

Control exposure to non-beam hazards

Control Measures Control Measures –– OverviewOverview

Control measures are based upon hazard evaluation and classification3 ANSI aspects of laser application influence hazard evaluation

The laser’s capability of injuring personnel


The environment in which the laser is usedThe personnel who may use or be exposed to the laser radiation

More comprehensive approach addsBeam pathProcess interaction


When we evaluate the work site When we evaluate the work site starting at the laser sourcestarting at the laser source

laser beam delivery

l


process

people

environment

Comprehensive viewComprehensive viewLaser

TypeOutputClass

Beam deliveryOpen beam

PeopleAncillaryConsumerUsers

TrainingErgonomic Factors


pEnclosedFiberCombination

ProcessReflectionsFumesRobotics, etc

PPEMaturity of judgmentLiteracy (read signs)

EnvironmentClean roomFactory/Job ShopOperating RoomFabrication AreaResearch Lab

Control Measures: Control Measures: Overview of ANSI Z136.1Overview of ANSI Z136.1--20072007

Two types of controlsEngineering (EC)Administrative & Procedural (A&P)


Priority of controls allows latitudePriority given to engineering controls (Section 4.1)If impractical or inadequate, A&P and PPE shall be used (4.1)EC may be replaced by…controls which provide equivalent protection (Section 4.2)


Control Measures: Control Measures: Overview of ANSI Z136.1Overview of ANSI Z136.1--20072007

Redundant controls – “more than one control measure that accomplishes the same purpose is not required.”E b dd d l (S ti 4 1 1 1)


Embedded laser (Section 4.1.1.1) –“control measures appropriate to the class of embedded laser shall be implemented when beam enclosures are removed…”Control measures apply for normal operation (4.1.1.1)

Three Functions with Laser Three Functions with Laser ApplicationApplication

OperationIntended use, normal use

MaintenanceTasks for assuring routine performanceCleaning and replenishment of expendable materials


Cleaning and replenishment of expendable materialsTypically, does not require beam access

ServiceInfrequent tasks (e.g., repairing faulty components)Usually require beam access

Control Measures:Control Measures:General Guidance from Section 4.1General Guidance from Section 4.1

Use the minimum radiation necessary for the application– only makes economic sense

Beam height should be at level other than that for


a sitting/standing person--- Can be difficult to achieve

Enclosure of equipment or beam path is preferred Engineering Control

Goal to make as near to a class 1 product as possible


Summary of Control MeasuresSummary of Control Measures

Table 10 ANSI Z136.1 summarizes requirementsEngineering and Administrative controls b l l


by laser class

Class 3B Laser Controlled Area Class 3B Laser Controlled Area ANSI Z136.1ANSI Z136.1--2007 Sec. 4.3.10.12007 Sec. 4.3.10.1

Posted with warning signOperated by authorized personnelOperated by trained personnelLimit beam path if extends beyond NHZ


Limit beam path if extends beyond NHZ8 “should” points - p. 33 in ANSI Z136.1-2007

Class 4 Laser Controlled Area Class 4 Laser Controlled Area ANSI Z136.1ANSI Z136.1--2007 Sec. 4.3.10.22007 Sec. 4.3.10.2

All “shall” and “should” requirements of Class 3b lasersCl l k d


Clearly marked “panic button” to interrupt laser beamEntryway controls:

non-defeatabledefeatableprocedural


Entryway Controls (4.3.10.2.2)Entryway Controls (4.3.10.2.2)

Non-defeatableDefeatable

allows override of i t l k


interlocksProcedural

individuals are trained and given PPE

DefeatableDefeatable Entryway ControlsEntryway Controls

Momentary by-pass switch

KeyKey Pad


SensorTime out functionGeared for authorized users useFrom outside and or inside the laser use area

Procedural Entryway Controls: Procedural Entryway Controls: PostingPosting


Light circuit should be interlocked to laser or lamp placed on a preventative maintenance schedule. This is not common practice


Procedural Entryway ControlsProcedural Entryway Controls

One method: laser curtain on overhead rail system forms entryway alcove with


entryway alcove with lab doorThis particular curtain includes an interlock switch, which is rare to find in practice

Temporary Laser Controlled Temporary Laser Controlled AreaArea

Generally applicable to “service” conditionsShall provide safety


Shall provide safety requirements within and outside areaPost “Notice” signCan be very useful to LSO

Temporary Laser Controlled Temporary Laser Controlled AreaArea

Laser curtains may be used to isolate a laser being serviced while other near-by


while other near by lasers continue normal operation

Note, sign pocket holding “Notice” signTraining of users required


Laser Barriers and CurtainsLaser Barriers and Curtains

Should not be flammable or


flammable or emit toxic by-

products

Laser Barriers and CurtainsLaser Barriers and Curtains

Must know damage threshold for a given time (usu. 60 or 100 sec)– Not real life, vendor may supply limited information


Barrier threshold limit (TL) = damage threshold

Range of TL’s: 10 to 350 W/cm2

TL = 1200 W/cm2 for 3 min for 1 metal barrier

Protective Housings/Guards: Protective Housings/Guards: Absorbing MaterialsAbsorbing Materials

Materials of construction include polymers, metals, glasses & building


glasses & building materials

Few materials have been tested & reported in scientific literature


Plastics with Dyes Often UsedPlastics with Dyes Often Used

Absorption by complementary color of beam (e.g., orange absorbs blue)


Provides qualitative guidanceDoes not provide information on penetration resistance (e.g., OD)

Plastics UsedPlastics Used

Plastics most often used include:

Poly(methyl methacrylate) such as Plexiglass


PlexiglassPolycarbonate such as Lexan

Plexiglass chamber at right is for argon laser (488 nm = blue light)

Polycarbonate for COPolycarbonate for CO22 LasersLasers

PC windows in semi-enclosure for plate cutting


for plate cutting laser

Semi-enclosure: open on top


Polycarbonate for COPolycarbonate for CO22 Lasers:Lasers:Conveyor EnclosuresConveyor Enclosures

Turn-key products are often Class IV due to CDRH definition of “human access” and

i


conveyor openings

LSO should determine if NHZ extends out conveyor entrance/exit

Laser Protective WindowsLaser Protective Windows

May be films, plastics, glasses

Shall be labeled


Shall be labeled with optical density and wavelengths, as well as damage threshold information

Enclose Beam PathEnclose Beam Path

Tubular, anodized aluminum beam tubes provide i id ti


rigid mountingHere, encloses beam from laser into optic then to regenerative amplifier


Enclose Beam PathEnclose Beam Path

Accordion enclosure contains beam for x-y movement“Limited open beam


Limited open beam path” exists between output aperture and metal sheetBarrier can be used a perimeter guard

Enclose and View RemotelyEnclose and View Remotely

Use of closed-circuit TV (CCTV) to view micro-material processing application


ppIn similar fashion CCD can be used to observe alignment stepsProcessing occurs in chamber beneath laser; access door is interlocked to laser

Fiber Optic Beam DeliveryFiber Optic Beam Delivery

Encloses beam between laser and output aperture


LSO could specify controls for “limited open beam path” between aperture and targetLabeling of fiber is strongly suggested


Interlock SwitchesInterlock Switches

Positive mode (break) interlock switchesNormally closed


Normally closed electrical contacts require forcible disconnectionDO NOT THINK ALL ENCLOSURES ARE INTERLOCKEDCheck labeling

Interlock SwitchesInterlock Switches

Conventional switches use spring action to open normally-closed contacts


May fail with contacts in closed position if spring breaks or plunger sticks

EYE EYE PROTECTION:PROTECTION:Some Factors to ConsiderSome Factors to Consider

Wavelength compatibilityAttenuation at that Wavelength (OD)


Wavelength (OD)Visual TransmittanceComfort and FitTrainingInspectionStorage


Wavelength CompatibilityWavelength Compatibility

Visible beam was transmitted through lens and damaged

b


carbon paper

IR-C beam was absorbed by and damaged plastic lens, while carbon paper is intact

Laser Safety Eye ProtectionLaser Safety Eye Protection

Glassscratch resistantstability against bleachingease for prescription


p plenseshigher optical qualitygood visual transmittance

Plasticlow weightbreak resistantLess expensive

Courtesy Innovative Optics

Optical Density (OD)Optical Density (OD)

Eyewear must be marked with OD as a function of wavelength

Laser eyewear is not for


Laser eyewear is not for direct viewing of the beam

Some manufacturers mark eyewear “DVO” for “diffuse viewing only” Just a reminderSome eyewear labeled with European code, hard to understand


Optical DensityOptical Density

OD can only be determined by measurement up to a value of 4.5 - 6.0Beyond that values must be extrapolated Therefore, laser eyewear may be marked


Therefore, laser eyewear may be marked OD>6Very high ODs e.g. > 10 are not meaningful

Optical Density Time Basis Optical Density Time Basis CriteriaCriteria

Criteria Time Basis (s)

Aversion Response 0.25


Near Infrared (0.7-1.4 mm) 10

Diffuse Viewing (visible beams) 600

Daily Occupational Exposure 30,000

Eyewear Care & StorageEyewear Care & Storage

Eyewear should be cleaned following manufacturer’s directions


Store it to keep away from contaminants & UV exposure

Store goggles to protect physical integrity


Protective Protective EyewearEyewear::Storage?Storage?

There is more than $1500 worth of laser protective


of laser protective eyewear stored in this box!

Inexpensive eyewear holderInexpensive eyewear holder


Protective Eyewear: Protective Eyewear: Things Not to DoThings Not to Do


Leave on the optics bench


Protective Eyewear:Protective Eyewear:Things Not to DoThings Not to Do

Stored by hanging by the elastic strap


Stretches (deforms) the strap

Allows dust to collect within


Stored by hanging from the


hanging from the strap. This has severely stretched the elastic headband


Replace the distended st ap ith


distended strap with surgical tubing

Fasten it in place with duct tapeIf this is still your eyewear, join real world and replace


Alignment eyewearAlignment eyewear

For visible laser use onlyOD for visible wavelengths below that of full protectionRisk does exist for user


Risk does exist for userAdvantage is beam can be seen

Signs and Area PostingSigns and Area Posting

Signal WordsCautionDangerNotice

Caution Signs


Caution SignsClass 2 and Class 2M

Danger SignsClass 3RClasses 3B and 4

Post required for Classes 3B & 4

Sample Warning Sign for Sample Warning Sign for Temporary Controlled AreaTemporary Controlled Area



Laser Warning Sign:Laser Warning Sign:Problem with Manual SwitchesProblem with Manual Switches

Light controlled by manual switch within labsThis was the only i li ht d d i


sign lighted during the audit, and no laser was in use in this lab!Easy to leave onBulbs burn out-replace with LEDs

Operating ProceduresOperating Procedures

Standard Operating ProceduresAlignment ProceduresRecommended for Class 3BRequired for Class 4


Required for Class 4Alignment procedures applicable if potential to radiation from embedded Class 3B/4 lasers

Use of Viewing CardsUse of Viewing Cards

Invisible laser radiation converted to visible wavelength


Visible “spot” of light is visible through eyewear



Laminated cards may produce specular reflections; study at 830 nm


Make surface diffusive by covering with matte-finish cellophane tapePurchase cards with diffusive surface


Wear protective eyewear for laser’s wavelength


Card inserted into beam path (handheld or on stand) you are looking at the diffuse reflection

Traditional IR viewersTraditional IR viewers



Alignment PracticesAlignment Practices

Work with a “buddy” or communicate to associates Review procedures


with buddyIdentify necessary equipment / materialsAlign from optic to optic

Alignment Practices: Alignment Practices: Equipment / MaterialsEquipment / Materials

View beams indirectly: remotely, thermal paper, ceramic disks, IR/UV viewing scopes, paper (business, 3x5) cards, phosphor viewing cards


Tools, targets, beam stops/blocks, curtains, signs, caution tapePPE for eyes and skin, as applicableEnsure OD is appropriate for beam power


Pay attention to housekeeping: remove unnecessary items


u ecessa y te sRemove jewelry and items from shirt pockets

Think about dangling ID badges



Reach into beam path to locate beam blocks with beam shutter closed


Be aware of increased risk of exposure if beam is elevated!View diffuse reflections only

Good laser practices Good laser practices

Purchase and use certified Class 1 laser products when possibleEnclose as much of the beam as possibleDon’t direct beam toward doors/windows


Don t direct beam toward doors/windowsDon’t locate beam at eye levelTerminate beams or reflections with fire-resistant beam stops

Good practice policesGood practice polices

Utilize surfaces that scatter radiation and minimize specular reflectionLocate controls so operator is not exposed to beam and non-beam hazardsMake sure warning/indicator lights can be

h h f l


seen through protective filtersView application remotely (CCTV, etc.)If contractors handle service, make sure controls for temporary laser controlled area are specified and followed


Section 9Section 9


Laser Safety Program Administration

General ConsiderationsGeneral Considerations

Recognized need: lasers are a known hazardManagement buy-in and supportLaser Safety Officer (LSO) named


Laser Safety Officer (LSO) namedProgram funding (expense items, training, etc.)

General Considerations: General Considerations: Basis for ProgramBasis for Program

Prevent injuries (moral, ethical consideration)Meet regulatory requirements (OSHA, state)


state)Reduce liability, control insurance costsAvoid negative publicity


Structure of ProgramStructure of Program

Small program: just the LSO, and probably part-time, tooCorporate program: responsible person with some level of authority at sites; site


y ;contacts (LSOs or safety technicians)Large program: LSO, deputy LSO, laser safety committee

Possible Structure of a Large Possible Structure of a Large ProgramProgram

DLSO

LSO


Medical Dept. Maintenance

Division LSO Division LSO Division LSO Division LSO

LSC

Possible Laser Safety Possible Laser Safety Committee MembershipCommittee Membership

RequiredLSODivision User RepresentativesManagement Representatives

Optional


OptionalMedical Division LSOs

LSC is not a requirement has pro & con


Laser Program Administration: Laser Program Administration: Documentation & Record KeepingDocumentation & Record Keeping

Hazard evaluation (can be part of SOP) NHZ, PPE, non-beam hazardsMedical approvalTraining – attendees (initial & retraining) and


Training attendees (initial & retraining) and materialsInventory – demonstrate control of 3B & 4Incident investigationsPeriodic checks and auditsSpecific procedures (e.g., alignment)

Laser Program Administration: Laser Program Administration: Other Important ElementsOther Important Elements

Auditing: Are we doing what we say we’re doing?Who does these? LSO, operating group, internal audit?What is the frequency? Daily, weekly, monthly annually?


monthly, annually?What level do they address? Nuts ‘n bolts, hazard identification? QA?In large facilities, probably a blend of local and LSO involvement.

Periodic Audits Periodic Audits –– Things to DoThings to Do

#1 Verify effective beam controls are in placeSuggest new controls as neededVerify laser inventory is current


Verify authorized users are currentExamine SOPsInspect eyewear – proper, condition, storagePerform/verify safety features audit of facilities & laser equipment –seldom doneBe visible – talk with laser users


Laser Program Administration: Laser Program Administration: Other Important ElementsOther Important Elements

TrainingThose with access to Class 3B and 4 beamsInitial and refresher trainingLaser safety overview or specific laser process?Confirm training by testing


Confirm training by testing

Medical SurveillanceMedical Surveillanceis now a should not a shallis now a should not a shall

Recommended: Class 3b/4 usersFrequency: pre-placement &


placement & following accidental exposurePersonnel categories

laser personnelincidental personnel

Medical Surveillance ExamsMedical Surveillance Exams

Incidental personnel: visual acuityLaser personnel

ocular historyvisual acuity


visual acuityAmsler Grid Testcolor vision responses

Users of UV lasersskin exampotential for photosensitization Amsler Grid


New Program steps New Program steps (regardless if laser use already in (regardless if laser use already in

place) Things to Doplace) Things to Do

1. Name & train LSO

2. Establish policy & institutional procedure

3. Establish inventory – What lasers are already here; where are they located; who is responsible for them?


New Program New Program –– Things to DoThings to Do

4. Perform hazard evaluationLaser applicationPotential exposure conditionsCollect necessary information & determine


MPEs, NHZs, ODs, etc.What are the non-beam hazards?Document all aspects well!

New Program New Program –– Things to DoThings to Do

5. Specify / approve control measures

6. User authorization – medical & training


7. Perform periodic audits

8. Identify issues & develop action plan


Can a laser safety environment be Can a laser safety environment be had??had??

The answer is yesIt requires management supportAn LSO who wants the job and is given the time


the timeA trained and aware work force


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