Laser Safety (Second Edition) : Practical Knowledge and Solutions

New chapters and updates highlight the second edition of Laser Safety: Tools and Training . This text provides background information relating to lasers and laser safety, and examines the components of laser work and laser safety from a different perspective. Written by a working laser safety officer, the book considers ways to keep users, as well as those around them, safe. The author encourages readers to think beyond protective eyewear. As it relates to safety, he determines that if eyewear is required, then the laser system is not ideal. This book factors in optics, the vibration elements of the optical table, the power meter, and user training, elements that are not commonly considered in the context of laser safety. It presents ways for users to evaluate the hazards of any laser procedure and ensure that they are following documented laser safety standards. The material serves as a fundamental means or road map for laser users seeking to utilize the safest system possible. What’s New in the Second Edition: The second edition provides an inclusion of the Z136.8 Research Laser Standard, and offers updates and an explanation of eye exposure limits (MPE), presents new cases studies, and presents practical example images. It includes coverage of, laser lab design lessons, addresses user facility challenges and laser disposal. Presents case studies of real accidents, preventive measures, and templates for documenting potential laser risks and attendant safety measures Reviews factors often overlooked when one is setting up a laser lab Demonstrates how to investigate a laser incident This text which includes fundamental laser and laser safety information, as well as critical laser use information, is appropriate for both the novice and the seasoned professional. PRELIMS.pdf Preface Acknowledgement Author biography Ken Barat List of contributors CH001.pdf Chapter 1 Why are laser accidents still happening? 1.1 Bad behavior and no negative consequences 1.2 Lessons learned/good practices 1.2.1 Common accident causes 1.3 Possible future: virtual reality 1.3.1 On-the-job training/mentoring (a topic you will find mentioned several times in this text, but learning is through repetition) 1.4 Recommendation 1.4.1 Trainer, what are your responsibilities? 1.4.2 Trainee, what are your responsibilities? 1.4.3 What makes up good coaching? 1.4.4 Training review CH002.pdf Chapter 2 Classification: a means of hazard communication 2.1 Cautionary note: laser classification by the LSO 2.2 Key item about laser hazard classification and why people care 2.3 Explanation of individual laser classes 2.4 System classification 2.4.1 Note on: limitations 2.4.2 IEC 2.4.3 CDRH 2.4.4 IEC 2.4.5 IEC class 1C 2.4.6 IEC 2.4.7 Classification changes that are being discussed 2.5 Classification based on control measures—laser control groups 2.6 Training slides on classification CH003.pdf Chapter 3 Biological effects: something you should know about 3.1 Confession time 3.2 Let’s be truthful 3.3 Oh! I forgot about that 3.4 What is all the concern over? 3.5 All aboard—train station analogy 3.6 Injury below damage threshold 3.7 Indoor problems below the MPE do exist 3.8 Equipment damage 3.9 So where do wavelengths go? 3.9.1 UV 3.9.2 Visible 3.9.3 Near-infrared 700 nm–1400 nm 3.9.4 Mid- and far-IR 3.10 How is damage caused? 3.11 The anatomy of your eye 3.11.1 The cornea 3.11.2 The aqueous chambers 3.11.3 The lens 3.11.4 The retina 3.11.5 The iris/pupil 3.12 800 nm trap 3.12.1 Damage mechanisms by wavelength 3.13 Things to know 3.13.1 Aversion response 3.13.2 Near IR effects 3.13.3 Injuries outside the fovea 3.13.4 Vitreal hemorrhages 3.13.5 Blood in the eye, toxic effects 3.13.6 Beam size does have an effect 3.13.7 Damn! Corneal injury hurts 3.14 Physiological damage mechanisms 3.15 Quick summary 3.16 Skin 3.17 Conclusion CH004.pdf Chapter 4 Laser safety terms: the language LSOs speak 4.1 Introduction 4.2 Definitions that explain laser safety 4.2.1 Maximum permissible exposure (MPE) 4.2.2 Nominal hazard zone (NHZ) 4.2.3 Nominal ocular hazard distance (NOHD) 4.2.4 Optical density (OD) 4.2.5 Irradiance 4.2.6 Accessible emission limit (AEL) 4.2.7 Continuous wave (CW) 4.2.8 Pulsed beam 4.2.9 Diffuse reflection 4.2.10 Specular reflection 4.3 Glossary of terms CH005.pdf Chapter 5 Risk assessment for lasers 5.1 Purpose 5.2 Applicability 5.3 Preface 5.4 Background 5.5 What is a risk assessment? 5.6 Fundamental concepts 5.7 Terms and definitions 5.8 Likelihood of occurrence (probability) 5.9 Consequence (severity) 5.10 Why is risk assessment important? 5.11 Where are risk assessments noted/required by regulations? 5.12 What is the goal of risk assessment? 5.13 What is acceptable risk? 5.14 Note on structure of the risk assessment worksheets CH006.pdf Chapter 6 Laser protective eyewear, looking sharp in the laser lab 6.1 Introduction 6.2 Eyewear labeling 6.2.1 What does > or + mean? 6.3 Can eyewear break down/fail? 6.4 Ultrafast pulses and laser eyewear 6.4.1 At a glance 6.4.2 Details 6.5 Angle of exposure 6.6 Attacked from behind 6.7 Unusual eyewear event #1 6.7.1 What to take away from this 6.8 Unusual eyewear event #2 6.9 Absorptive versus reflective filter 6.10 Impact resistance 6.11 Manufacturer protection curves and non-labelled wavelengths 6.12 What to do if labeling wears off? 6.13 Prescription eyewear 6.14 Alignment eyewear 6.15 European labelling 6.15.1 Important notice to reader 6.15.2 Protection level 6.15.3 EN code 6.16 Storage of eyewear 6.16.1 Cleaning/disinfecting of eyewear 6.16.2 Bleach precautions 6.16.3 Best practice 6.16.4 What about UV devices for cleaning—be careful 6.16.5 Future of laser eyewear 6.17 Conclusion CH007.pdf Chapter 7 Regulations, you mean there are rules? 7.1 Introduction 7.2 Standards and regulations 7.3 Export control 7.3.1 University guidance examples 7.3.2 Example #2 7.4 Outdoor use 7.4.1 Non-MPE effects 7.5 What if you manufacture lasers? 7.5.1 Outside the United States, meaning the rest of the world 7.6 Laser users 7.6.1 Outside the United States 7.6.2 Within the United States 7.7 US States that have a laser regulatory programs 7.8 ANSI Z136 7.8.1 Special note overlooked by many 7.9 ANSI control measures 7.10 Concluding thoughts CH008.pdf Chapter 8 Safety culture and laser program management 8.1 Defining safety culture 8.2 Identifying and improving safety culture 8.2.1 Worker feedback 8.2.2 Leading and lagging indicators 8.3 Safety culture and the laser safety program 8.3.1 Laser safety officer 8.3.2 Risk assessments and standard operating procedures 8.3.3 Laser safety training 8.3.4 Change management 8.3.5 Continuous improvement 8.3.6 Incident investigation 8.3.7 Root cause analysis 8.3.8 Team-based investigations 8.4 Conclusion CH009.pdf Chapter 9 Performance-based learning in laser safety training 9.1 Introduction 9.1.1 Training vs competency 9.2 Alignment demonstration 9.2.1 More examples 9.3 Examples that apply PBL to laser safety training 9.3.1 Eyewear selection 9.3.2 Service of class 1 product 9.3.3 Control area challenge 9.3.4 Accident review 9.3.5 Lab design 9.4 Value of these PBL exercises 9.5 Alignment class material 9.5.1 The results 9.6 Conclusion CH010.pdf Chapter 10 Training, breaking through to users 10.1 Training 10.2 Training vs competency 10.3 Institutional—required by regulations and standards 10.4 Training techniques and approaches 10.4.1 Online courses 10.4.2 Webinar/video conference approach 10.4.3 Virtual reality (VR) approach 10.4.4 Augmented reality (AR) AI approach 10.4.5 Written handout 10.5 On-the-job training—site/equipment specific 10.6 Refresher training 10.7 Service staff challenges 10.8 Mobile app training, an effective training delivery approach 10.9 Microlearning? 10.10 Game learning 10.11 Just-in-time learning, safe plan of action 10.12 On-the-job training—OJT or is it just mentoring? 10.12.1 How long should it take? 10.12.2 How should OJT be performed? 10.12.3 What needs to be covered? 10.12.4 Who should the mentor be? 10.12.5 Do as I say, not as I do 10.12.6 Does OJT need to be documented? 10.12.7 Is follow-up needed? 10.13 More on refresher training 10.13.1 Why refresher training? 10.13.2 How do existing standards address the idea of refresher training? 10.14 Effective refresher training, what are one’s options? 10.14.1 Frequency is an important factor 10.14.2 Refresher conclusion 10.15 Standards and training 10.16 Training record retention 10.16.1 Use of training records 10.16.2 Management and administration 10.17 Conclusion CH011.pdf Chapter 11 Mentoring, do what I say and follow my lead 11.1 Introduction 11.1.1 As a side note 11.2 Goal of mentoring 11.3 The ten core laser safety principals 11.4 How to be a good mentor or trainer? 11.5 For those that like it short and simple 11.6 A hard lesson for those giving OJT/mentoring 11.6.1 Hold direct answers back 11.7 What about mistakes? 11.8 Commonly overlooked topics 11.9 Safety culture 11.10 Conclusion CH012.pdf Chapter 12 Can everyone understand your work? Considering visual disabilities when designing graphics and presentation 12.1 Introduction 12.1.1 Disability and ethics 12.1.2 Types of visual disabilities 12.1.3 Why do we care? 12.2 Color deficient vision 12.2.1 Color vision 12.2.2 Types of deficient color vision 12.2.3 Other visual disabilities 12.3 General strategies for accommodating color vision impairments 12.3.1 Color choice 12.3.2 Textures and patterns 12.3.3 Color as an aid 12.4 Considerations for all visual disabilities and conditions 12.4.1 Accessibility for electronic media 12.4.2 Contrast 12.4.3 Describing images 12.4.4 Publications 12.4.5 Safety and visual impairment 12.4.6 Online training References CH013.pdf Chapter 13 Managing laser safety across multiple sites 13.1 Introduction 13.2 Responsibilities and accountability 13.2.1 The DLSO 13.2.2 Clarifying responsibilities 13.3 Standardization 13.3.1 People focused 13.3.2 Clear communication 13.4 Cultural relevance 13.4.1 Safety culture matters 13.5 Inspect what you expect 13.6 Summary References CH014.pdf Chapter 14 Ergonomics in a laser lab, you must be joking 14.1 Introduction 14.2 Lab ergonomics, reaching across the table 14.3 Typical work activities and posture 14.3.1 Do you have back pain? 14.4 Getting higher 14.5 Standing around 14.6 Weight/lifting 14.7 Vertical breadboard 14.8 Work hours 14.9 Concluding thoughts CH015.pdf Chapter 15 Laser safety tools: making your life better for less 15.1 Introduction 15.2 Carbon resin lightweight breadboards 15.3 Vertical breadboards 15.4 Black AL foil 15.5 Diffuse reflection material 15.6 Indirect laser beam viewing tools 15.6.1 Laminated IR viewing cards 15.6.2 IR viewers 15.6.3 Hands-free IR viewer 15.6.4 CCD/webcam 15.7 Beam blocks 15.7.1 Unsecured beam blocks 15.7.2 Home-made beam blocks 15.8 Beam dump 15.9 Polycarbonate sheets 15.10 Plastic laser enclosures 15.11 Metal laser enclosures, table perimeter guards 15.12 Laser curtains 15.13 Laser protective eyewear 15.14 Piping insulation as shelf/head guard 15.15 Are there more products out there? CH016.pdf Chapter 16 Evaluation and design of laser barriers 16.1 Introduction 16.2 Laser barrier definition 16.3 Laser barriers—curtain style 16.3.1 Overview—laser barrier curtains 16.3.2 Laser barrier curtain materials 16.4 Barrier selection 16.4.1 Wavelength dependency 16.4.2 Permeability 16.4.3 Formability 16.4.4 Accessories 16.4.5 Particulates 16.4.6 Life safety 16.4.7 Other environmental needs 16.4.8 Aesthetics 16.5 Laser barrier curtain design 16.5.1 The ceiling 16.5.2 Height 16.5.3 Valance 16.5.4 The floor 16.5.5 Access and egress 16.5.6 Windows 16.6 Laser barriers—partition style 16.6.1 Overview—laser barrier partitions 16.7 Laser barrier partition design 16.8 Laser barriers for optical tables 16.9 Laser barriers for windows 16.10 Laser barriers at a doorway 16.10.1 Closed vestibule 16.10.2 Open vestibule 16.11 Final thoughts CH017.pdf Chapter 17 US and European test methodology for laser protective eyewear 17.1 Introduction 17.2 ANSI and the Z 136.7 test specification 17.2.1 Typical laser test setup 17.2.2 Laser saturation 17.3 DIN and the EN 207 test specification 17.3.1 Wavelength range considerations 17.3.2 Pulse width considerations 17.3.3 Laser parameters used in DIN EN 207 17.4 Performance of EN 207 specification 17.4.1 Significance of the read across 17.5 Conclusion CH018.pdf Chapter 18 Elements and considerations in designing and or selecting a room interlock system 18.1 Introduction 18.1.1 Hazard assessment 18.2 Minimal system for attended operation 18.3 Emergency shutoff button 18.4 Basic interlock circuit 18.5 Shutter placement 18.6 Interlocks for unattended operation 18.7 Exit vs. emergency exit 18.8 Reach back cascade 18.9 Design considerations for interlock systems 18.10 Complex interlock systems 18.11 Configuration control CH019.pdf Chapter 19 Considerations when specifying laser eyewear for ultrafast applications 19.1 Brief overview short pulse lasers 19.2 Unanticipated laser hazards associated with ultrafast lasers 19.2.1 Absorption in organic molecules 19.2.2 Saturation at short pulse widths 19.3 EN 207, EN 11254 and the relevance of the ‘M’ rating 19.4 Conclusion References CH020.pdf Chapter 20 Paperwork considerations (not documented, not done) 20.1 Introduction 20.2 ISO 9001, just a quick word 20.3 Record retention 20.4 Training records 20.4.1 On-the-job training records 20.5 Standard operating procedures 20.6 Audit records 20.7 Laser safety chapter 20.8 Accuracy of warning and contact signs and postings 20.9 Alignment eyewear approval 20.10 Temporary authorization/temporary work authorization 20.11 Interlock checks 20.12 Conclusion CH021.pdf Chapter 21 Explaining engineering control measures found in standards 21.1 Introduction 21.2 Engineering controls 21.2.1 Protective housing 21.2.2 Interlocks on removable PH 21.2.3 Service access panel 21.2.4 Key control 21.2.5 Collecting optics 21.2.6 Area warning device 21.2.7 Laser radiation emission warning (usually visible) 21.2.8 Emergency conditions 21.2.9 Class 4 entryway controls 21.2.10 Non-defeatable approach 21.2.11 Defeatable controls 21.2.12 Administrative control 21.3 Conclusion CH022.pdf Chapter 22 Illuminated sign, a closer look 22.1 Introduction 22.2 Lighting source 22.3 Placement 22.4 Color has meaning 22.4.1 A green light 22.4.2 A yellow light 22.4.3 A red light 22.5 Illuminated warning sign, ANSI or IEC style 22.6 Multiple lasers in one room 22.7 Conclusion CH023.pdf Chapter 23 Dye laser, hazards and good practice for safe use 23.1 Introduction 23.2 Dyes and solutions 23.3 Preparation for dye work 23.4 Supervisor and staff responsibilities 23.4.1 Equipment, concerns 23.5 Real work rules 23.5.1 Protect yourself 23.6 If there is a spill 23.7 More on dyes 23.8 Laser dye/solvent control classes CH024.pdf Chapter 24 Laser disposal, end of life cycle thoughts, hospice for your laser 24.1 Introduction 24.2 Why should you care? 24.3 E-waste 24.4 What are my responsibilities? 24.5 Questions for the user 24.6 User responsibilities 24.7 Questions for hazardous waste transporter or handler 24.8 Questions for surplus receiver 24.9 General approaches to laser disposal 24.10 Power supplies 24.11 Optics 24.12 Dye lasers 24.12.1 Active concerns 24.12.2 Disposal 24.13 Excimer lasers 24.13.1 Active concerns 24.13.2 Disposal 24.14 Diode/semiconductor lasers 24.14.1 Active concerns 24.14.2 Disposal 24.15 Diode/telecommunications laser systems 24.15.1 Active concerns 24.15.2 Disposal 24.16 Conclusion CH025.pdf Chapter 25 How are you dealing with these topics? 25.1 Chapter note 25.2 20 smart work practices—all are important, number sequence does not relate to safety or order of importance 25.3 Ventilation 25.4 Access control 25.5 Housekeeping/storage 25.6 Layout of optics 25.7 Periscope 25.8 Cable and hoses 25.9 Optics and cable identification 25.10 Pump diffuse scatter 25.11 Signage on entryway door 25.12 Beam tube braces Laser safety is undoubtedly incredibly important when running any optical lab. This book is a detailed guide to laser safety methods and is highly useful for people who regularly work with lasers and similar technologies. Throughout the text laser safety basics are explored as well as effective techniques to promote a culture of laser safety. A key part of this book explores varied topics that are less well covered in industry standard guides. These include ergonomics, mentoring, performance-based learning, on the job training, laser safety tools, solutions and specific guidance for laser disposal. As this book is written by experts in the field the text is extremely relevant for both the university sector and industry. The key audience for this book includes laser physicists, safety professionals, students and researchers.Key FeaturesProvides a thorough review of laser safety basicsExplains laser safety devices Includes techniques to obtain workable laser safety cultureDemonstrates risk analysis approaches