Laser Safety Training - The Safety Zone,...

Laboratory for Laser Energetics — Laser Safety Training L_001 S-SA-M-028 Rev D (2017-07-25) 1 / 58

Eugene Kowaluk Laser Safety Officer (LSO) Laboratory for Laser Energetics (LLE) University of Rochester (University)

Laser Safety Training


The safety of personnel conducting laser operations and research is of primary importance Do this! Not this!

• Although you may not realize it, many stray beam paths may exist

• Know your work area and activities being performed around you

The goal of this training is to provide you with a reminder of safety policies and

updates on laser safety


Summary

●  Lasers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 ●  Potential laser hazards . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 ●  Laser classifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 ●  Control measures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 ●  Engineering controls . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 ●  Administrative & procedural controls . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 ●  Administrative & procedural controls — Warning signs . . . . . . . . . . . . . 29 ●  Personal protective equipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32 ●  Non-coherent sources . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45 ●  Avoiding injury . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48 ●  Laser radiation injuries . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51 ●  Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57 ●  Instructions on satisfying laser-safety training requirements . . . . . . . . . 58


Lasers are coherent, monochromatic, & directional Lasers

*Courtesy, laser-professionals.com

High Reflectance Mirror (HR)

Output Coupler Mirror (OC)

Active Medium

Output Beam

Excitation Mechanism

Optical Resonator

Excitation mechanism: this is the source of energy to excite the atoms to a proper energy state and can be optical, electrical, or chemical Optical resonator: this reflects the laser beam through the active medium for amplification and consists of a high-reflectance mirror and an output coupler mirror

Active (or lasing) medium: This can be a solid (crystal), semiconductor (diode), liquid (dye), or gas, which contains atoms that can emit light by stimulated emission —The laser beam’s

wavelength is determined by the lasing medium


Laser spectrum with added LLE sources

Original, courtesy, laser-professionals.com

ASBO = Active Shock BreakOut diagnostic @ LLE Omega = Omega Laser Facility including OMEGA & OMEGA EP


The LLE laser inventory identifies almost 400 lasers

Uses include

• Beam Characterization • Laser Development

• Damage Testing • Metrology

• Electro-optic Sampling • Non-linear Optics

• Alignment • Holography

• Optical Quality Control • Index Measurement

• Pulse Shaping • Interferometry

• Reflectometry • Spectroscopy

All of these uses have the potential for exposing personnel to dangerous levels of

laser radiation


• Many lasers at LLE are capable of causing eye injury to anyone who looks directly into the beam or its reflections

• High-power laser beams can burn exposed skin, ignite flammable

materials, and heat materials that release hazardous fumes • Any apparatus required to produce and control laser energy may also

introduce additional hazards

Laser beams can cause serious eye and skin injuries Potential laser hazards


There are many potential hazards associated with lasers that are non-beam related

• Electrical hazards from power supplies, capacitors (even after the power is turned off), discharge lamps, producing x rays, ultraviolet (UV), visible, infrared (IR), microwaves

• Additional electrical hazards can occur during laser set-up or installation, maintenance, and service, where protective covers are often removed to allow access

• Other hazards include excessive noise from high-power lasers, explosive flash-lamp failure, fire hazards, and mechanical hazards associated with lifting

Maximum Permissible Exposure (MPE): The level of laser radiation to which an unprotected person may be exposed without adverse biological changes in the eye or skin

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Reported incidents, nationwide, have shown that

Accidents and injuries related to lasers are most often associated with the following, specific conditions: 1. Available eye protection not used! 2. Misaligned optics and upwardly directed beams. 3. Unanticipated eye exposure during alignment. 4. Equipment malfunction. 5. Improper methods of handling high voltage. 6. Unintentional exposure of unprotected personnel. 7. Operators unfamiliar with laser equipment. 8. Lack of protection for ancillary hazards. 9. Improper restoration of equipment following service. 10. Failure to follow standard operating procedures (SOPs).

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Laser radiation damage mechanisms differ

• Continuous wave (CW) lasers: as defined by the ANSI standard are lasers that have a continuous output longer than ¼ second (our blink response)

• CW lasers can cause

– Thermal damage

– Photochemical degeneration

– Low-level chronic exposure

• Pulsed lasers: as defined by the ANSI standard are lasers that have a single or pulsed output shorter than ¼ second

•  Pulsed lasers can additionally cause

– Blast damage


Anatomy of the human eye*

Choroid

Aqueous

Cornea

Macula

Optic Nerve

Sclera

Vitreous

Retina Lens

*Courtesy, laser-professionals.com


Laser wavelength determines where the energy gets deposited in the eye

•  Ultraviolet (UV) radiation (180-400 nm) causes damage to the cornea

– Excessive ultraviolet exposure produces photophobia, an intolerance to light

– Adverse effects are usually delayed for several hours after the exposure but will occur within 24 hours

– Cumulative exposure can contribute to cataracts (clouding of the lens)

•  Visible (400-700 nm) and infrared (IR) radiation (700-1400 nm) can damage the retina

•  The eye can intensify (focus) light 100,000 times making eye exposure the principal hazard associated with laser radiation


Your large skin surface makes it readily available to accidental exposures to laser radiation

• UV, visible, and IR exposure can cause pigment darkening, photosensitive reactions, & skin burn

•  Chronic exposure to UV wavelengths (200-400 nm) can have a carcinogenic effect

•  Reducing the surface area of exposed skin decreases the risk of accidental exposure to laser radiation


Laser radiation can cause irreversible damage to the eyes and skin

• The principal cause of tissue damage is thermal in nature – Thermal effects are caused by a rise in temperature following

absorption of laser energy

• Other damage mechanisms include photochemical reactions and carcinogenic effects

The number 1 cause of all laser eye accidents is unsafe operating practices combined with

the failure to properly use laser protective eyewear!


Lasers are classified according to their hazards Laser classifications

**Courtesy, lasersafetyfacts.com

**

Class 3B and Class 4 lasers require a review of safety procedures, engineering and administrative controls, and

personal protective equipment prior to use at LLE


Laser Optical Fiber Transmission Systems

• Laser transmission systems which employ optical fibers shall be considered enclosed systems with the optical fibers forming part of the enclosure

• If disconnection of a connector results in radiation emission below the applicable MPE, then connection or disconnection may take place in an uncontrolled area and no other control measures are required

• If greater than above the applicable MPE via a connector, then the following will take place (ANSI 4.5.2): – Fibers attached to Class 3B or Class 4 lasers or laser systems shall not be

disconnected prior to preventing the beam from entering the fiber

– If laser radiation above the applicable MPE can be made accessible by disconnection of a connector, the connector shall bear a label or tag with the words “Hazardous laser radiation when disconnected”

– To prevent inadvertent personnel exposure from an unterminated or severed fiber, there should be lockout/tagout provision at the laser source


Federal and New York State regulations

•  American National Standards Institute (ANSI) – American National Standard for Safe Use of Lasers (Z136.1-2014)

•  Occupational Safety and Health Administration (OSHA)

– This U.S. agency requires personnel to observe the ANSI recommendations for the safe use of lasers, and not following the ANSI recommendation can result in fines

•  U. S. Food and Drug Administration (FDA) – The FDA is responsible for radiation-emitting product safety

http://www.fda.gov/Radiation-EmittingProducts/RadiationEmittingProductsandProcedures/ HomeBusinessandEntertainment/LaserProductsandInstruments/default.htm

•  New York State Department of Labor

– Labor Law Part 50. LASERS http://www.labor.ny.gov/workerprotection/safetyhealth/sh50.shtm

Control measures


LLE’s laser safety documents are accessible online

http://safety.lle.rochester.edu/520_training/presentations.php


Engineering controls are given primary consideration for limiting access to laser radiation

Engineering controls are the most effective types of controls. They are designed and incorporated into the laser system, and include

• protective housings

• beam stops and attenuators

• interlocks

• key control

• service access panels

• viewing portals

Each proposed experiment or operation involving a laser must be evaluated to determine the hazards involved and the required safety measures & controls

Engineering Controls


An example of engineering controls addressing the safety of the computer user in a laser environment

Any location where stray laser light could shine towards workers sitting at a computer requires barrier protection


Administrative and procedural controls qualify and supplement use of engineering controls and PPE

These controls include • Laboratory Instructions, directives, and operating procedures • Safety training orientations and annual refreshers. • On-the-job training & laser operator qualification (“Qual Card”) • “Buddy System” • Laser safety signs • Laser inventory and safety surveys • Resources in the safety library with texts, standards, government

regulations, and laser-hazard analysis software available to all • Web-based resources • Monthly safety inspections, in addition to event-generated inspections

that include new installations

Administrative & procedural controls


Before installing any new Class 3B or 4 laser system, a laser registration/safety survey is required The form may be downloaded from http://safety.lle.rochester.edu/570_laser/LaserSafetySurvey.pdf

(continued on reverse side)

Laboratory for Laser Energetics University of Rochester

LASER SAFETY SURVEY (ONE LASER PER FORM)

THE FOLLOWING INFORMATION IS REQUIRED BY THE UNIVERSITY Place a copy of this completed survey, along with a copy of the appropriate laser manufacturer's specification sheet, in the Laser Safety Binder for the laboratory where the laser is installed/used. Return the original survey to the Laser Safety Officer, Eugene Kowaluk (LLE East mailbox). Room no. _______ Room name __________________________________________

Responsible Individual(s) & Group ________________________________________

Emergency Contact ____________________________________________________

MANUFACTURER (IF IN-HOUSE, THEN LLE) _________________________________ MODEL (IF LLE, THEN NAME OF SYSTEM) __________________________________ SERIAL NUMBER (IF ANY) ______________________________________________ Laser CLASSIFICATION (CLASS 1, 1M, 2, 2M, 3R, 3B, or 4) ____________________ YEAR MANUFACTURED _______________________________________________ TYPE (CW OR PULSED) ________________________________________________ Description (LASING MEDIUM) __________________________________________ MAXIMUM OUTPUT __________________________________________________ OPERATIONAL WAVELENGTH(S) [nm] _____________________________________ PULSE WIDTH/REPETITION RATE ________________________________________ Beam DIVERGENCE _________________________________________________ EMERGENT BEAM DIAMETER ___________________________________________ Operational (Active or Inactive)? ______________________________________ LLE Tag No. (if any) ________________________________________________ Purpose _________________________________________________________

Please answer the following questions with Y (yes), N (no), or NA (not applicable)

Documentation • Have all laser operators had laser-safety orientation? ................................................... _____ • Will all operators of this laser be qualified? ..................................................................... _____ • Has the principal investigator approved the operating procedures? ............................... _____ • Have all laser operators been informed of emergency procedures? .............................. _____ • Are there any laser operators who are students? ............................................................. _____ • Where are the written operating procedures located? ________________________________

LL AA SS EE RR II NN VV EE NN TT OO RR YY

LLE Laser Safety Survey (cont.)

2003.10.22, revised 2017.07.24, EKowaluk

Personal Protective Equipment — Laser Protective Eyewear • Do operators wear laser-protective eyewear? ................................................................ _____ • Is the eyewear available for visitors? .............................................................................. _____ • Is all eyewear labeled? ................................................................................................... _____ • Is non-laser-safety eyewear stored with laser-protective eyewear? ............................... _____

Personal Protective Equipment — Other • Are gloves and ultraviolet-protective eyewear available for UV use? ............................. _____ • Is the needed personal protective equipment available for cryogenic liquids? ............... _____ • Is personal protective equipment available for chemicals? ............................................. _____

Warning System • Are the appropriate warning signs accurate? ................................................................. _____ • Are there appropriate warning signs on the door? .......................................................... _____ • Are the signs functional? (please contact LSO if bulbs need replacement) ................... _____ • Is the warning system an alarm, warning light, or verbal announcement? ..................... _____

Service • Is this laser built in-house? ............................................................................................. _____ • Is in-house service available for this laser? .................................................................... _____ • If not, please list the service company’s name _____________________________________

Beam Paths • Are beams terminated at the end of the useful path? ..................................................... _____ • Is any beam path at eye level? ....................................................................................... _____ • Is the laser oriented away from doors and aisles? ......................................................... _____ • Do personnel use jewelry when using lasers? ................................................................ _____ • Are Class 4 beam enclosures fabricated from fire-resistant materials? ......................... _____ • Are optical systems aligned using cameras or devices to minimize eye exposure? ...... _____

Unattended Operations • Is this system operated unattended? .............................................................................. _____ • Are the doors locked or interlocked during operation? ................................................... _____

After-hours Operations • Are operators using the “Buddy System”? ...................................................................... _____ • Have the operators received approval from their supervisor? ........................................ _____

Electrical Safety • Are energized components enclosed? ........................................................................... _____ • Is the laser enclosure properly grounded? ..................................................................... _____ • Are extension cords in use? (extension cords are prohibited) ........................................ _____

Chemical Safety • Are the chemicals stored properly according to hazard class? ...................................... _____ • Is secondary containment used for associated equipment (pumps)? .............................. _____ • Are Safety Data Sheets (SDS) available for all chemicals? ........................................... _____ • Are compressed gas cylinders stored properly (upright, labeled, strapped)? ................. _____ • Are halogenated gases used in exhaust system designed for them? ............................ _____ • Is a Class B:C fire extinguisher within 50 ft of locations where solvents are used? ....... _____ Signoff _________________________ Date ____________________________ Print Name ______________________


Equipment which employs laser systems must satisfy LLE Instruction 7700

LLE Instruction 7700, Design and Integration of Equipment, is a comprehensive document detailing specifics of LLE policy in qualifying equipment for operation. It can be found at http://www.lle.rochester.edu/media/resources/documents/7700.pdf Within this Instruction are safety protocol checklists, including the Safety Risk Assessment Checklist and the Pre-Operation Safety Inspection Checklist, which are required for the Installation/Operations Readiness Review


Laser safety binders are required in every laboratory with Class 3B and Class 4 lasers

• Each individual laboratory’s principal investigator is responsible for maintaining this binder

• LLE laser safety binders, along

with the SDS binders, are reviewed during the safety inspections


Qualification is required for Class 3B & Class 4 laser operators

• All original qualification cards are on blue card stock and are maintained by the Omega Laser Facility Division Administrative Assistant (Rm 276A) who issues and tracks them

• Copies of each card are to be kept with the laser binder in the appropriate laboratory

• New operators may be qualified by existing qualified operators, but a Certified Laser Operator still has to sign off on the Examination and Certification line


Only Certified Laser Operators may sign qualification cards

They are the

•  Omega Laser Facility Director

•  Omega Operations Manager

•  OMEGA & OMEGA EP Laser Facility Managers

•  Omega Laser-Sources Group Manager

•  Omega Optomechanical Group Manager

•  Optics & Imaging Sciences Group Leader

•  Laser Development Laboratory Group Leader

or others who are designated by the Laser Safety Officer


LLE’s “Buddy System” — Peer health advocacy

• LLE’s “Buddy System” requires that you work with a colleague, any time you work in a potentially hazardous environment or using potentially hazardous equipment

• Buddies are responsible for

– Remaining in the work area

– Verifying proper PPE and procedures are employed

– Monitoring each other’s activities

• Supervisors are responsible for knowing

– When staff are working off-hours

– The nature of activities being performed

– That the Buddy System is being adhered to

• The “Buddy System” as applied to laser safety, either during or after normal working hours, requests that you always challenge co-workers who are not using required laser protective eyewear


Supervisors have the inherent responsibility to educate their staff

Supervisors, liable for their staff and students, must set an example in addition to providing information regarding

• instructions on the safe use of lasers

• fundamentals of laser operation

• details on LLE policies, including eye exams (if exposed), laser-safety instruction, and laser-operator qualification,

• Warning signs address different levels of risk (laser, electrical, chemical, mechanical, et al.)


Warning signs address different environments

Although accident prevention signs are classified by ANSI Z535.2, the laser standard, ANSI Z136.1, along with the Center for Devices and Radiological Health, use the following signal words • DANGER — Indicates an immediately hazardous situation which, if not

avoided, will result in death or serious injury. Only Class 3B & Class 4 lasers require this signal word, “DANGER”

•  CAUTION — Indicates a potentially hazardous situation which, if not

avoided, may result in minor or moderate injury. “CAUTION” may also be used to alert against unsafe practices. The signal word “CAUTION” shall be used with Class 2, 2M, & Class 3R that do not exceed the applicable MPE

•  NOTICE — Indicates company policy as the message relates directly or

indirectly to the safety of personnel or protection of property

CAUTION

DANGER

NOTICE

Administrative & procedural controls — Warning signs


Warning signs are designed to deal with different laser environments

• Please notify the laser-safety officer when you think there is a problem with the sign flashing, a light bulb out, or error in wording

• Although most signs have two bulbs, some have only one bulb

Toggle-switched or non-lit signs • shall be turned on/displayed before a laser is turned on, and • shall not be left on when all of the relevant lasers are turned off • If startup is initiated from within the room, and the lights were not

previously enabled or warning displayed, inform persons in the lab that source is being turned on & verify that proper eyewear is in use

Turn off or remove all warning signs when all the laser sources were confirmed to be off


Custom warning signs are made for each laboratory to address specific hazards

• Color is added to immediately give attention to the laser wavelength being used inside the laboratory

• The signal word in this case, DANGER, alerts visitors to the possibility of injury

• Although the sign wording is constantly visible, the alert is only in effect when the light is flashing

Signal Word

Hazard

Action Statements


Eye Protection Guidelines

•  Put on laser protective eyewear before entering a laser hazard area •  Wear eyewear to current prescription •  Keep your eyewear high on the bridge of your nose •  Wear your eyewear as close as possible to your eye – use eyewear straps •  Turn your head toward the object you want to see (do not look around your

laser protective eyewear) •  Although our eyewear is designed to protect us, never look directly into the

laser beam. Some eyewear manufacturers even point out that they offer protection against accidental exposure to stray or diffused reflection for a maximum exposure of only 10 sec

•  The color and/or darkness of your laser protective eyewear’s lens does not unambiguously indicate the protection the lens provides, either in wavelength or optical density – e.g., eyewear with green filters will not protect you from “green” laser

light

Personal Protective Equipment


Eye Protection Guidelines — Understanding Optical Density (OD)

•  Optical Density* (OD) characterizes the fraction of light blocked (absorbed) by laser protective eyewear – When OD=1 at some wavelength, 90% (a factor of 10) of the incoming

light at that wavelength is blocked – When OD=5 at some wavelength, 99.999% (a factor of 100,000) of the

incoming light at that wavelength is blocked •  Make sure that the OD listed on the eyewear is equal or greater than the

OD required for every wavelength listed on the sign – The OD can be specified for a single wavelength or a range of

wavelengths – The OD of laser-protective eyewear refers to their absorbance of light,

possibly both visible and invisible *OD = log10(1/T), where T=transmittance

A higher OD value means the eyewear will provide greater protection at the

specified wavelength(s)


Care and maintenance of protective eyewear

•  Check and clean the eyewear before every use and after, if necessary

•  Appropriate cleaners are provided; if you use a towelette, blow off any dust or dirt to avoid scratching the lens

•  Immediately remove eyewear from service when lenses or frames are scratched, cracked, or broken. Return it to the Laser Safety Officer for disposal

•  Laser protective eyewear that is provided in specific areas or for specific tasks must NOT be removed from that area, especially if another lab’s eyewear does not have the appropriate wavelength and/or OD for a given application

•  Contact your supervisor to obtain replacement prescription safety eyewear, or the work area supervisor for non-prescription safety eyewear

•  Store safety eyewear in a protective case or in designated storage locations when not in use


Laser protective eyewear is necessary when other control measures do not prevent exposure to hazardous radiation

•  Goggles provide more protection than spectacles from impact, dust, liquid splash, and optical radiation hazards (ANSI Z87, 6.1.2)

•  Eyewear that fit poorly will not afford the protection for which they were designed (ANSI Z87, 6.2.5)

•  Protective eyewear is more likely to be worn properly when it fits comfortably and doesn't impede vision

•  Ensure that the right size and shape is selected for a particular person

•  Safety eyewear having headband temples are easily adjustable for a secure fit and are useful for tasks requiring movement

•  Safety eyewear employing headbands should have the breakaway feature if used in an environment where a strangulation hazard is possible (i.e., wearing laser eyewear with a headband while putting on impact safety goggles when going to the machine shop)


How to obtain prescription lenses for laser protective eyewear

LLE will reimburse you for prescription eyewear inserts 1. One vendor of laser protective eyewear with the prescription insert is

the Honeywell Sperian XC series frames • These inserts (prescription lens holder) may be obtained from the

Omega Facility Administrative Assistant 2. Take the insert to your eyewear vendor of choice, and pay for it 3. For reimbursement, take the receipt to your division’s reimbursement

individual


Eyewear retainers should be properly secured

Retainers are available from the laser safety officer


All LLE laser protective eyewear must comply with two ANSI standards

• ANSI standard for laser safety, Z136.1, and

• ANSI standard for mechanical impact resistance, Z87.1


This eyewear is labeled with the wavelengths for which they offer appropriate protection

There are two labeling standards used on protective laser eyewear:

• American National Standards Institute (ANSI), and

• European and labeled with “CE”

We have no control over labeling by a supplier nor is the labeling consistent, even with the same vendor. If you have a question on the labels, please ask your supervisor or contact the laser-safety officer

Do not use the CE labeling on laser protective eyewear All LLE signs use the ANSI standard

whose wavelength is shown in nanometers (nm)


Eyewear identified with LLE added labels

• If it is necessary to use laser safety eyewear at wavelengths other than those listed on the lens by the manufacturer, contact the Laser Safety Officer or Chief Safety Officer BEFORE putting them into service. They MUST be measured and labeled with an LLE serial number to demonstrate they are suitable.

• A copy of the measurement shall be maintained in the laboratory


This eyewear is not appropriate for a laser environment

Verify that you are using the correct

laser protective eyewear every time you enter a laser

work area


Eyewear storage units are labeled to prevent mixing of different types of eyewear protection

Remember to return safety eyewear to their original location


Verifying appropriate laser protective eyewear using laser safety software — EASY HAZ™

EASY HAZ™ Basic Web Version. Their laser hazard analysis software is free and online at

http://lasersafetyu.kentek.com/easy-haz-laser-hazard-software-basic-web-version/

• It provides minimal hazard calculations; see restrictions online EASY HAZ™ Professional LSO Edition has extended capabilities and can be found, along with its instructions, at our internal online access

• Only one person at a time can access this software • Mac users, use Microsoft Remote Desktop.app • PC users, use the Remote Desktop Connection • Login to the LLE computer easyhaz as lleguest; password is lleguest • From the easyhaz desktop you can access the EASY HAZ™ app or the

folder in which its instructions reside


Fluorescence — an eyewear response when struck by a laser beam

• Fluorescence is the re-emission ("glow") of absorbed (laser) light. Some materials used for laser protective eyewear exhibit fluorescence following exposure to laser light.

• Fluorescence is frequently at a different wavelength (color) than the (laser) source

• Eyewear fluorescence can startle the wearer, and cause the wearer to question its effectiveness

• If eyewear fluorescence is observed, it indicates unmanaged/stray laser beams are present that must be eliminated

• Individuals who observe eyewear fluorescence should pay close attention to effects to their vision, and seek immediate medical evaluation if there is any concern of possible injury

• All personnel should be trained to realize the benefit of eyewear fluorescence, and be instructed to eliminate the potentially dangerous situation that caused it


Non-laser, intense UV sources can also be potential hazards

•  Caution signs shall be prominently displayed

•  If necessary, customized enclosures should be constructed

•  If in doubt, the manufacturer’s eyewear should be tested for proper blocking of UV light

Non-coherent sources


Custom-built UV enclosure

Notice: full-face protection used at this installation


Potential retinal hazards from blue light-emitting diodes (LED)

Harmful effects. Severe headaches and nausea caused by blue light triggering the eye muscles to shut down. Intense blue light is also capable of causing permanent photochemical damage to the eye.

• The intensity of the blue light is often undetected because the sensitivity of the human eye falls drastically at 400 nm

•  Normally, the viewer would blink or look away from an intense light source

•  However, an intense blue light source is especially dangerous because it does not appear to be bright and a viewer's natural reaction to look away does not provide protection from long-term exposure

•  The viewer may look at such a source for many seconds or minutes without their blink response ever kicking in

•  Also known as high-energy visible light, 380-530 nm, and specifically a blue-light hazard, 400-500 nm


Media often depicts unsafe work practices

Don’t follow these examples or allow safety to be compromised in your work areas

Avoiding injury


It is the responsibility of the individual to act properly in a laser environment General laser safety recommendations include:

• Enable the laser warning lights/signs before enabling the laser source • Wearing eye protection

– make sure you check the laser signs – make sure the wavelength(s) for which you require protection and OD

are confirmed on the eyewear – look in the mirror before you enter a laser environment to confirm fit

• Using the minimum power level for the required application • Terminating the beam path • Employing appropriate “lockout/tagout” • Not looking directly into the laser beam or at a specular or diffuse

reflection, regardless of its power Laser disposal

• Once it’s determined to be nonfunctional & non-repairable, the laser is removed from the laser inventory & untagged

• As long as there are no other hazardous materials in the laser (container/housing) they can be disposed of as electronic waste


Follow these guidelines for proper beam control

1. Securely mount the laser on a stable platform to maintain the beam in a fixed position during operation

2. Confine primary beams and dangerous reflections to a defined area. 3. Orient the laser so that the beam is not directed towards entry doors

or aisles 4. Design the beam path so it is not at eye level when standing or when

sitting at a desk 5. Enclose the beam path when practical 6. If the above is not feasible, use side barriers, which can easily be

removed and replaced 7. Identify beam paths and ensure that they do not cross populated areas 8. Terminate every beam path 9. Minimize transient reflections: remove watches & jewelry, and be

careful with tools


Examples of retinal damage caused by lasers Laser radiation injuries


Result of not wearing laser protective eyewear

•  An undergraduate student was working at a national laboratory with a Class 4 laser to suspend particles

•  Neither the student nor the supervising scientist were wearing laser protective eyewear

•  As the student bent down to look into the chamber, she saw a flash and immediately noted a reddish brown substance floating in her left eye

•  The student had irreversible eye damage—a retinal traumatic hole caused by pulsed laser light

•  RESULT—This accident contributed to the stand-down of this national laboratory, ultimately costing over $100 million*

**GAO report GAO-06-83, http://www.gao.gov/new.items/d0683.pdf


The response to a suspected exposure to laser radiation is well defined

• Instruct the individual with a suspected eye injury to go to the University’s University Health Service (UHS) or an ophthalmologist

• Instruct the individual with a suspected skin injury to see a physician

• Inform the supervisor and LLE administration

• The supervisor will fill out an LLE incident report

• LLE administration will complete a University incident report form SMH115


Laser pointers can be dangerous

•  The safest laser pointers are those which do not exceed 1 mW output •  Laser pointers can cause temporary flash blindness •  The FDA has issued warnings about the possibility of eye damage to

children from hand-held pointers and has indicated that the light energy from a laser pointer aimed into the eye can be more damaging than staring directly into the sun

•  The FDA and ANSI Z136.1-2014 restrict a laser pointer's emission limit to 5 mW in the visible spectrum (Class 3R); 2 mW in the infrared

•  Recent tests by the National Institute of Standards and Technology (NIST) show that 90% of green pointers and 44% of red pointers tested were out of compliance with federal safety regulations* – Green laser pointers frequency-convert infrared laser light. Poorly

designed devices may emit both green and potentially injurious invisible IR light

*www.nist.gov/pml/div686/pointer-032013.cfm


Injuries & consequences associated with laser pointers

•  Eye doctors at Iceland’s Landspitali University Hospital treated a 13-year-old boy who was seriously injured in both eyes after playing with a 90-milliwatt laser pointer purchased outside the country. He was said to have lost central vision in one eye.*

•  Medical helicopter pilot blinded by a laser and has to make emergency landing; an arrest was made

•  From the FBI: “If you point a laser and interfere with the operation of an aircraft, that’s a felony. The crime carries a maximum of 20 years in federal prison and a quarter of a million dollars fine. In addition, the FAA can impose a civil penalty of up to $11,000 for each violation.” **

*http://www.laserpointersafety.com/news/news/nonaviation-incidents_files/383588a2c761851796992941a921673c-300.php#on

**http://www.fbi.gov/news/videos/making-a-point-about-lasers


FDA recommends that consumers be cautious when buying laser products over the internet*

•  Consumers may unknowingly purchase an illegal laser product or may lose their money if the illegal product is refused entry into the U.S.

•  The brightness of a laser beam does not always indicate its relative power or potential for injury in comparison to other color laser beams. Powerful blue or violet lasers will appear less bright in comparison to equally powerful red laser beams and much less bright in comparison to equally powerful green laser beams

•  A blue or violet laser beam that appears as bright as a red or green laser is very likely to be a powerful laser that can cause immediate eye damage. Blinking or looking away when exposed directly to the beam may not provide sufficient protection to avoid injury to the eye

*http://www.fda.gov/Radiation-EmittingProducts/RadiationSafety/AlertsandNotices/ucm116534.htm


Many hazards are associated with lasers

Laser operators and those working in a laser environment • must be provided with instructions on the safe use of lasers • must be made aware of the hazards • must follow recommendations for proper use of lasers

Class 3B and Class 4 lasers require a review of safety procedures, engineering and administrative controls, and personal protective equipment prior to use

All laser, regardless of class, should be used with care and with each user understanding the risks and safe work practices

required for the installation

Summary


Instructions on satisfying the laser-safety training requirements

1. Visit the LLE Safety Zone ”Training" tab http://safety.lle.rochester.edu/520_training/presentations.php

2. Read the L_001 Laser Safety Training presentation 3. Complete and submit the L_001 quiz !!• New employees/students – after receiving your graded quiz, contact the

LSO for an orientation • Any comments on this presentation and/or the on-line quiz can be

recorded at the end of the quiz in the comment box and be submitted with your answers

Note: S-SA-M-028 = LLE Project Data Management (PDM) document number

Date post:	09-Sep-2018
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