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AMAZON multi-meters discounts AMAZON oscilloscope discounts INTRODUCTION The use of laser technology has been increasing ever since its introduction in the 1960s. This text concerns itself with laser safety, so let us ask the questions: Are laser accidents happening? Do we have bodies to count? The simple answers are yes, laser accidents are occurring, and the number is uncertain. One survey of laser accident databases showed more than 1500 accidents from 1960 to 2002. Approximately 70% involved eye injury. A small number of reported accidents (approximately 3%) resulted in deaths. These deaths were due to either electrocution or the effects of operator room fires caused by laser radiation. Statistically this seems like a small number. As in any reporting system, laser safety professionals believe the number of laser accidents is under-reported. Also, trauma to the eye is dramatic, even if the effect passes with time. This section will present examples of real laser accidents. Some are equipment-related and others are the result of user error. A number of isolated databases track laser accidents. In the United States , the Food and Drug Administration tracks equipment-related laser accidents. Other federal agencies that track their own accidents are the Department of Energy, the Army, the Navy, the Air Force, and the Federal Aviation Administration. In addition, some private industry groups have databases. The most common factors contributing to laser accidents are: 1. Unanticipated eye exposure during alignment 2. Available laser eye protection not being used 3. Equipment malfunction 4. Improper high voltage handling methods 5. No protection provided for ancillary hazards 6. Incorrect eyewear selection 7. Inhalation of laser-generated air contaminants 8. Viewing of laser-generated plasmas (blue light hazard) 9. Improper use of equipment ----2 ALIGNMENT ACTIVITIES Once the laser beam path is set and established, unless you place yourself or a reflective object in the path or approach the beam with a bend magnetic around your neck, the beam will stay on its appointed path. So it can easily be seen that the overwhelming number of laser accidents or injuries occur when laser optics are being manipulated. Reflections off tools, optical mounts, lenses, or mirrors are the chief cause of random or unexpected laser beams. (See the section on guidelines to practice during laser alignment.) In addition, changes in temperature in the laser area, cooling water, and other factors can induce beam errors. The time and effort spent performing laser alignment can range from a few minutes to more than 5 hours. Temperature changes in the room, thermal expansion of optics and mounts, and dust all play a critical role in how smoothly an alignment of a laser-based system goes and how long it can take. Whether manipulations are manual or done by computer controls is another factor. A beam may disappear from the expected path, and then one has to find it and bring it back into the path. Remember that laser alignment does not relate to visible beams only, but more commonly to invisible beams, where a variety of alignment aids is needed. The techniques for laser alignment listed below are to be used to help prevent accidents during alignment of a laser or laser system. Above: Fig. 1 Peer pressure can lead to accidents (author's favorite laser cartoon; see Dr. Fun Web page for others June 26, 1997 and July 2, 1997 ). ----2.1 PREPARATION FOR ALIGNMENT 1. To reduce accidental reflections, remove watches, rings, dangling badges, necklaces, and reflective jewelry before any alignment activities begin. 2. Use of nonreflective tools should be considered. 3. Access to the room or area is limited to authorized personnel only. 4. Consider having at least one other person present to help with the alignment. 5. All equipment and materials needed are present prior to beginning the alignment. 6. All unnecessary equipment, tools, and combustible materials (if the risk of fire exists) have been removed to minimize the possibility of stray reflections and nonbeam accidents. 7. Persons conducting the alignment have been authorized by the responsible individual. 8. A notice sign is posted at entrances when temporary laser control areas are set up or unusual conditions warrant that additional hazard information be available to personnel wishing to enter the area. ----2.2 ALIGNMENT CONSIDERATIONS 1. Whoever moves or places an optical component on an optical table (or in a beam path) is responsible for identifying and terminating every stray beam coming from that component (meaning reflections, either diffuse or secular). 2. All laser users must receive an orientation to the laser use area by an authorized laser user of that area. 3. There must be no intentional intrabeam viewing with the eyes. 4. Coaxial low-power lasers should be used when practical for alignment of the primary beam. 5. Reduce beam power with ND filters, beam splitters, or dumps or by reducing power at the power supply. Whenever practical, avoid the use of high-power settings during alignment. 6. Laser protective eyewear must be worn at all times during the activity. 7. Beam blocks must be secured (labeled if possible). 8. Have beam paths at a safe height, generally below eye level when standing or sitting. If necessary, place a step platform around the optical table. 9. The laser safety officer (LSO) has authorized eyewear with reduced optical density (OD) to allow the beam spot to be seen. Measures must be taken and documented to ensure that no stray hazardous specular reflections are present before the lower-OD eyewear is worn. Full protection OD eyewear, as listed in the laser table, is to be worn again once alignment is complete. The reduced-OD eyewear is labeled as alignment eyewear and is stored in a different location than the standard laser eyewear for this operation. 10. Skin protection should be worn on the face, hands, and arms when aligning at ultraviolet (UV) wavelengths. 11. The beam is enclosed as much as is practical. The shutter is closed as much as is practical during course adjustments. 12. Optics and optics mounts are secured to the table as much as is practical. Beam stops are secured to the table or optics mounts. 13. Areas where the beam leaves the horizontal plane must be labeled. 14. Any stray or unused beams are terminated. 15. Invisible beams are viewed with infrared (IR)/UV cards, business cards, card stock, craft paper, viewers, 3 × 5 cards, thermal fax paper, Polaroid film, or by a similar technique. Operators are aware that such materials may produce specular reflections or may smoke or burn. 16. Pulsed lasers are aligned by firing single pulses when practical. 17. Intrabeam viewing is not allowed unless specifically evaluated and approved by the LSO. Intrabeam viewing is to be avoided by using cameras or fluorescent devices. ----2.3 ALIGNMENT CONCLUSION Normal laser hazard controls must be restored when the alignment is completed. Controls include replacing all enclosures, covers, beam blocks, and barriers and checking affected interlocks for proper operation. ----3 FAILURE TO WEAR PROTECTIVE EYEWEAR Probably 99.99% of laser alignment accidents occur with the injured party not wearing laser protective eyewear. The excuses are common. "I cannot find a pair that fits." "I cannot see the beam." "They are too heavy." "They cost too much." "I know the set-up well enough. I don't need them." "I am using visible beams. I will see where the beam goes." Many of these have a similar tone to the excuses first heard when seat belts became mandatory. ----3.1 SOLUTION The solution lies in two areas: selecting the correct eyewear and peer pressure. If the eyewear selected has a comfortable fit and provides good visual light transmission and protection, many reasons for not wearing eyewear are taken out of the equation. As for peer pressure, if it’s acceptable to not wear eyewear, the practice will continue. Supervisors and the laser user community in an institution have to police each other. ----4 ELECTRICAL HAZARDS OVERLOOKED Laser systems and electricity go hand in hand; electric shock is the second most commonly reported incident associated with laser use. Power supplies, flash lamps, batteries, capacitors, poor grounding, and accessible wires all can be found in the majority of laser systems. All need to be addressed and respected. The laser user needs to remember that between 6 and 20 mA is sufficient current to bring about the "let-go effect," meaning you become part of the circuit and you cannot let go. Equipment circuit breakers are there to protect the equipment, not the users. ----5 ADDITIONAL HAZARDS AND SOLUTIONS A long list of additional hazards can be associated with laser work, such as pressure vessels, robotics, and so on. These will be explained and expanded on in Section 13. ----6 IMPROPER RESTORATION OF LASERS AFTER SERVICING While good work practice calls for any interlock bypass to be built so that the device cannot be restored back to service with the bypass in place, this is not the common practice. Items as thin as a paper clip or tape have been used to bypass interlocks, such as micro switches. The solution involves a checklist, for both the service person and the user accepting the finished work. Both need to see that all safety systems are operational (including interlocks and warning lights) and that all enclosures and housings are secure. ----7 LACK OF PLANNING Planning means not only having all the proper tools available for the work, but having the correct eyewear and setting up warning signs and an exclusion zone to protect others in the work area. ----7.1 SOLUTION Reading the procedures and developing checklists ahead of time are the best cures for a lack of planning. Many times a lack of planning goes along with rushing, which has led to numerous accidents. Checklists should list not only the activities to be performed but what tools are required to start the task. The weakness of checklists is the person or team using them. If an activity is routine, sometimes even when reading the checklist, people don’t really pay attention to the list; they are anticipating the response. Every pilot knows not to take off without going through a preflight checklist. At times this becomes so rote that expected responses are checked rather than the actual instrument readings. An excellent addition to a checklist is a digital photo of each step. ----7.2 CHECKLIST FOR DEVELOPING A CHECKLIST 1. Define the task:
2. Checkpoint list:
3. Sort the checkpoints; create a road map to be followed:
4. Flesh out categories:
5. Determine the order of the categories:
6. Perform a initial review of the checklist:
7. Revise the checklist:
8. Format the checklist:
9. Evaluate the checklist:
10. Finalize the checklist:
11. Apply the checklist:
12. Review and update the checklist:
----8 WEARING THE WRONG EYEWEAR AND IMPROPER FIT There is not a universal pair of laser protective eyewear, at least not until the virtual imaging helmet becomes available. Therefore, users must pay attention to the specifications of the pair they are using. Is it designed for the wave lengths they may be exposed to? Is it at the appropriate OD to provide full or, in the case of alignment eyewear, partial protection? Is the eyewear in good physical shape? Have its protective features been compromised (scratches, bleaching)? Does it fit the user's face? Wearing the wrong laser protective eyewear has injured people (approximately 4% of reported accidents). The solution is for laser protective eyewear to be labeled or coded with its OD and the wavelength range it’s designed to protect you from. In some cases labeling will indicate if the eyewear is full protection or alignment, continuous wave or pulse. ----8.1 EYEWEAR FAILURE If one is dealing with laser beams that can burn through eyewear, why, then, are engineering controls not in place to prevent one from being in a situation where direct facial exposure is possible? Sometimes the correct eyewear was not chosen; either the OD was too low or the eyewear needed to be safety hardened but was not. The solution is to inspect eyewear before each use. Look for scratches and signs of physical stress. Read the labeling and check for wavelength compatibility and correct OD. Evaluate the hazard from the beam; determine if remote viewing is the proper safety solution. ----9 FATIGUE AND STRESS These two factors can make the most diligent laser user a menace to himself or herself and others. ----9.1 FATIGUE My mind clicks on and off. I try letting one eyelid close at a time while I prop the other with my will. But the effect is too much, sleep is winning, my whole body argues dully that nothing, nothing life can attain is quite so desirable as sleep. My mind is losing resolution and control. (Charles Lindbergh about his 1927 transatlantic flight) While people associate fatigue with feeling tired, few realize how serious fatigue at the workplace can be, particularly when working around photons moving at the speed of light. With very few exceptions, the average adult needs between 7 and 8 hours of sleep a night to be adequately alert for the other 16 to 17 hours that include commuting, work, and leisure and family time. Without the proper amount of sleep, the body cannot and won’t function to its potential. Symptoms of fatigue include a decreased ability to concentrate on multiple tasks, reduced ability to analyze new information, fixation, short-term memory loss, impaired judgment, impaired decision-making ability, reduced ability to think logically, daytime drowsiness and micro-sleeps, reduced motor skills and coordination, reduced ability to think critically, distractibility, reduced visual perception, loss of initiative, personality changes, depression and a feeling of indifference to one's performance, and increased reaction time. The majority of attention to worker fatigue has been directed to two large groups: those in the transportation industry (truck drivers, pilots, and long trip private drivers) and second- and third-shift workers. A study published in the journal Sleep estimated that 52.5% of all work-related accidents may be related to sleepiness. After all the investigations were complete, these disasters were attributed to fatigue: the Exxon Valdez oil spill, the Chernobyl power plant explosion, the Challenger explosion, Three-Mile Island , and Bhopal . With the rapid increase in technological capability, it’s not our machines that fail us; it’s the operator. Human errors are the primary cause of 90% of all accidents. One night of disrupted sleep probably won’t result in huge catastrophes, but most people don’t have just one night of disrupted sleep. Night after night they try to get by on less sleep than their bodies need. Sleepiness builds into a sleep debt because the effects of inadequate sleep are cumulative. For example, assume an adult needs 8 hours of sleep each night but only gets 7. By the end of a week there is a 7-hour sleep debt, which is the equivalent of going one full 24-hour period without the proper amount of sleep. In college this is called pulling an all-nighter. Now let us figure the sleep debt for an individual who only gets 6 hours of sleep each night (which seems to be more accurate for most Americans). At the end of the week, that sleep debt is 14 hours - or two all-nighters. The bottom line is that as fatigue increases, your risk of causing an accident increases. The solution is simple, but in many work situations it seems as far away as the end of the day. Take breaks and get proper rest. Remember that whatever time one thinks is too valuable to use to break away and take a short rest is nothing compared to time lost to an accident. Documented cases show that operations shut down from 1 day to 4 months during accident investigations and while obtaining authorization to operate again. ----9.2 STRESS Stress to get the job done and perform for others and pressures from management can lead to lapses in good judgment, For example, bypassing standard control measures to take short cuts. Taking these short cuts and bypassing standard operating procedures can cause serious injuries to those who know the right way to do things. It’s a derivation of the saying, "Do as I say, not as I do." 2.1 What is Stress? Webster's defines stress as a physical, chemical, or emotional factor that causes bodily or mental tension and that may be a factor in disease causation. Physical and chemical factors that can cause stress include trauma, infections, toxins, illnesses, and injuries of any sort. Emotional causes of stress and tension are numerous and varied. While many people associate the term stress with psychological stress, scientists and physicians use this term to denote any force that impairs the stability and balance of bodily functions. A mild degree of stress and tension can sometimes be beneficial. Feeling mildly stressed when carrying out a project or assignment often compels us to do a good job and to work energetically. Likewise, exercising can produce a temporary stress on some body functions, but its health benefits are indisputable. It’s only when stress is overwhelming, or poorly managed, that its negative effects appear. Job stress can be defined as the harmful physical and emotional responses that occur when the requirements of the job don’t match the capabilities, resources, or needs of the worker. Job stress can lead to poor health and even injury. The concept of job stress is often confused with challenge, but it’s not the same. Challenge energizes us psychologically and physically, and it motivates us to learn new skills and master our jobs. When a challenge is met, we feel relaxed and satisfied. Thus, challenge is an important ingredient for healthy and productive work. Some employers assume that stressful working conditions are a necessary evil - that companies must turn up the pressure on workers and set aside health concerns to remain productive and profitable in today's economy. Research findings challenge this belief. Studies show that stressful working conditions are associated with increased absenteeism, tardiness, and intentions by workers to quit their jobs - all of which have a negative effect on the bottom line. Recent studies of so-called healthy organizations suggest that policies benefiting worker health also benefit the bottom line. A healthy organization is defined as one that has low rates of illness, injury, and disability in its workforce and is also competitive in the marketplace. Stress solutions can range from resetting goals to a realistic level to re evaluating staffing levels to breaking tasks into smaller, more manageable sections. Sometimes it’s as simple as the realization that just like fatigue, if stress is not recognized and dealt with, serious accidents can occur, in addition to loss of productivity and staff illness. ----10 WORKPLACE CULTURE A corporate or workplace culture is - like any other culture - a set of behaviors and codes that people use to govern their interactions with each other. This includes both formal, written company policies and informal rules of the road that you learn with experience. A workplace culture that calls for 12- to 16-hour work days and applies constant pressure to produce will have a history of accidents and employee health problems. In academic and medical settings the culture is well established that allows and accepts over-working and under-valuing graduate students and residents. Is it any wonder that this population (graduate students) makes up such a large portion of those involved in laser accidents and near misses? 10.1 SOLUTION Changes in workplace culture must come from the top. Risk management needs to show management how much time is lost in sick days and what the actual productivity is with such a culture. The quality of work performed and creativity is the goal - not the number of hours worked. ----11 TO WHOM ARE THESE ACCIDENTS HAPPENING? The majority of laser accidents don’t happen to novice laser users, but to experienced laser-use personnel. Usually when those with little laser experience are exposed, they are similar to the drunk driver victim: the innocent by-stander. Approximately 70% of reported accidents are made up from the following four groups: 1. Scientists 2. Students 3. Technicians 4. Patients (number 1 group for reported deaths) Other population categories make up the remaining 30% of the reported incidents: 1. Industrial workers 2. Doctors and nurses 3. Pilots and military personnel 4. Spectators 5. Laser show operators 6. Field service staff 7. Office staff ----12 THE PERCEIVED INCIDENT Sometimes an investigation will result from the perception of an injury. Even if you believe that no exposure occurred, the investigation has to be handled in a professional manner. The perception incident might demonstrate a flaw in the safety system or at the least, in training. If the investigation is handled in a manner that makes the reporting party feel as if his or her concerns are not being considered seriously, future incidents won’t be reported. Worse, the next incident may be reported to a higher level or regulatory agency, all of which may damage the effectiveness of your program. ----13 ACCIDENT INVESTIGATION For the LSO or laser safety advisor, the goal is to prevent laser accidents and incidents, but one must be prepared to investigate an accident or incident that is reported. Below are the elements of accident investigation. ----13.1 WHO SHOULD LEAD THE ACCIDENT INVESTIGATION? The LSO should be the lead contact on a laser-related incident. Many LSOs also perform several other functions. Therefore, it might be necessary to turn the accident investigation over to another person or even an outside party. The ideal would be to have an investigation conducted by someone who is an expert in accident causation; experienced in investigative techniques; and fully knowledgeable of the work processes, procedures, persons, and industrial relations environment of the situation. Unfortunately, most of us live in the real world. Don’t be afraid to call on any resources in your own firm. ----13.2 WHO AND HOW MANY PEOPLE SHOULD INVESTIGATE AN ACCIDENT? Depending on your work setting, an incident may be investigated by only the LSO, while in some settings both management and labor may have representation on the team. ----13.3 SHOULD THE IMMEDIATE SUPERVISOR BE ON THE TEAM? The advantage is that this person is likely to know the most about the work and persons involved and the current conditions. Furthermore, the supervisor can usually take immediate remedial action. The counter-argument is that there may be an attempt to gloss over the supervisor's shortcomings in the accident. This situation should not arise if the worker representative and the management members review all accident investigation reports critically. ----13.4 HOW DO YOU MAKE SURE THAT INVESTIGATORS ARE IMPARTIAL? An investigator who believes that accidents are caused by unsafe conditions will likely try to uncover conditions as causes. One who believes accidents are caused by unsafe acts will attempt to find the human errors that are causes. Therefore, it’s necessary to examine briefly some underlying factors in the chain of events that ended in the accident. ----13.5 REASON FOR THE INVESTIGATION: WHY ARE WE DOING THIS? When accidents are investigated, the emphasis should be concentrated on finding the root cause of the accident rather than the investigation procedure itself. Once a laser accident or suspected incident has been reported to the facility LSO, swift action needs to be taken. First, work at the scene needs to stop. This is to determine what happened so corrective action steps can be taken to prevent it from occurring again. You are looking for a positive outcome; this is not a television crime scene where all parties are guilty. It’s not uncommon to find that several people knew about the problem or the actions that caused the injury but took no action to see that it was corrected. Written statements from the injured party and those in the area are important. Taking digital photos to help explain the scene and provide greater understanding is a great aid and time saver. Review written procedures if they exist as well as the training procedures of those involved. Did they understand the risk? Had they performed this activity before? Gather evidence from many sources during an investigation. Get information from witnesses and reports as well as making direct observations. Inter view witnesses as soon as possible after an accident. Inspect the accident site before any changes occur. Take photographs and make sketches of the accident scene. Record all pertinent data on maps. Get copies of all reports. Documents containing normal operating procedures, flow diagrams, maintenance charts, or reports of difficulties or abnormalities are particularly useful. Keep complete and accurate notes in a bound notebook. Record pre-accident conditions, the accident sequence, and post-accident conditions. In addition, document the locations of victims, witnesses, machinery, energy sources, and hazardous materials. All parties should remember that most importantly, accident investigations are conducted to find out the causes of accidents and to prevent similar accidents in the future. They are not hunts for someone to blame the incident on (not finger pointing exercises). Even laser incidents that involve no injury or property damage should still be investigated to determine the hazards that should be corrected. The same principles apply to a quick inquiry of a minor incident and to the more formal investigation of a serious event. As little time as possible should be lost between the moment of an accident and the beginning of the investigation. In this way, one is most likely to be able to observe the conditions as they were at the time, prevent disturbance of the setting, and identify witnesses. The steps in accident investigation are simple: the accident investigators gather information, analyze it, draw conclusions, and make recommendations. Although the procedures are straightforward, each step can have its pitfalls. As mentioned above, an open mind is necessary in accident investigation. Preconceived notions may result in wrong paths being followed while leaving significant facts uncovered. All possible causes should be considered. Making notes of ideas as they occur is a good practice, but conclusions should not be drawn until all the information is gathered. ----13.6 SUMMARY OF INVESTIGATION STEPS 1. Stop work. 2. Get an understanding of the activity. 3. Take digital images. 4. Get statements from all involved. 5. Review existing procedures. 6. Review training records. 7. Follow-up: a. Develop corrective action plan, with user buy-in. b. Implement the plan. c. Prepare lessons learned and distribute them. d. Evaluate the effectiveness of the corrective action. ----13.7 PHYSICAL EVIDENCE Before attempting to gather information, examine the site for a quick overview, take steps to preserve evidence, and identify all witnesses. Based on your knowledge of the work process, you may want to check items such as: 1. Positions of injured workers 2. Equipment being used 3. Materials being used 4. Safety devices in use 5. Position of appropriate guards 6. Position of controls of machinery 7. Damage to equipment 8. Housekeeping of area 9. Weather conditions 10. Lighting levels 11. Noise levels 13.8 TASK Here the actual work procedure being used at the time of the accident is explored. Members of the accident investigation team look for answers to questions such as: 1. Was a safe work procedure used? If not, why not? 2. Had conditions changed to make the normal procedure unsafe? 3. Were the appropriate tools and materials available? 4. Were they used? 5. Were safety devices working properly? 6. Was lockout used when necessary? 7. Was the worker distracted? If yes, why was the worker distracted? 8. Was the worker trained? If not, why not? ---13.9 EQUIPMENT ISSUES To seek out possible causes resulting from the equipment and materials used, investigators might ask: 1. Was there an equipment failure? 2. What caused it to fail? 3. Was the machinery poorly designed? 4. Were hazardous substances involved? 5. Were they clearly identified? 6. Was a less hazardous alternative substance possible and available? 7. Was the raw material substandard in some way? 8. Should personal protective equipment (PPE) have been used? 9. Was the PPE used? ----13.10 ENVIRONMENTAL FACTORS 1. What were the weather conditions? 2. Was poor housekeeping a problem? 3. Was it too hot or too cold? 4. Was noise a problem? 5. Was there adequate light? 6. Were toxic or hazardous gases, dusts, or fumes present? 13.11 HUMAN FACTORS 1. Were workers experienced in the work being done? 2. Had they been adequately trained? 3. Can they physically do the work? 4. What was the status of their health? 5. Were they tired? 6. Were they under stress (work or personal)? ----13.12 MANAGEMENT The investigation team or person has to feel confident in their role to look at management's role in the accident. Management holds the legal responsibility for the safety of the workplace, and therefore the role of supervisors and higher management must always be considered in an accident investigation. Answers to any of the preceding types of questions logically lead to further questions such as: 1. Were safety rules communicated to and understood by all employees? 2. Were written procedures available? 3. Were they enforced? 4. Was there adequate supervision? 5. Were workers trained to do the work? 6. Had hazards been previously identified? 7. Had procedures been developed to overcome them? 8. Was regular maintenance of equipment carried out? 9. Were regular safety inspections carried out? ----13.13 GATHER BACKGROUND INFORMATION Often an overlooked source of information can be found in documents such as technical data sheets, maintenance reports, past accident reports, formalized safe work procedures, and training reports. Any pertinent information should be studied to see what might have happened and what changes might be recommended to prevent recurrence of similar accidents. ----13.14 EYEWITNESS ACCOUNTS Witnesses should be interviewed as soon as it’s practical after the accident. If witnesses have an opportunity to discuss the event among themselves, individual perceptions may be lost in the normal process of accepting a consensus view where doubt exists about the facts. Although there may be occasions when you are unable to do so, every effort should be made to interview witnesses. In some situations witnesses may be your primary source of information because you may be called upon to investigate an accident without being able to examine the scene immediately after the event. Because witnesses may be under severe emotional stress or afraid to completely open up for fear of recrimination, interviewing witnesses is probably the hardest task facing an investigator. Witnesses should be interviewed alone, rather than in a group. You may decide to interview a witness at the scene of the accident where it’s easier to establish the positions of each person involved and to obtain a description of the events. However, it may be preferable to carry out interviews in the quiet of an office where there will be fewer distractions. The decision may depend in part on the nature of the accident and the mental state of the witnesses. ----13.14.1 Interviewing: Getting a Story or Facts Interviewing is an art that cannot be given justice in a brief document such as this, but a few dos and don'ts can be mentioned. The purpose of the interview is to establish an understanding with the witness and to obtain his or her own words describing the event. ----13.14.2 Interview Details 1. Get preliminary statements as soon as possible from all witnesses. 2. Arrange for a convenient time and place to talk to each witness. 3. Explain the purpose of the investigation (accident prevention) and put each witness at ease. 4. Listen, let each witness speak freely, and be courteous and considerate. 5. Take notes without distracting the witness. Use a tape recorder only with the consent of the witness. 6. Use sketches and diagrams to help the witness. 7. Emphasize areas of direct observation. Label hearsay accordingly. 8. Be sincere and don’t argue with the witness. 9. Record the exact words used by the witness to describe each observation. Don’t put words into a witness' mouth. 10. Word each question carefully and be sure the witness understands. 11. Identify the qualifications of each witness (name, address, occupation, years of experience, etc.). 12. Supply each witness with a copy of his or her statements. Signed statements are desirable. [ Do ] Put witness at ease Explain you want to determine what happened and why Let them talk and listen Try to sense underlying feelings Take short notes Confirm that you have all statements correct [ Do Not] Intimidate the witness Interrupt or prompt Show your own feelings or emotions Take lengthy notes while the witness is talking ----13.14.3 What Type of Questions to Ask? Ask open-ended questions that cannot be answered by simply "yes" or "no." The questions you ask the witness will naturally vary with each accident, but some general questions should be asked each time: 1. Where were you at the time of the accident? 2. What were you doing at the time? 3. What did you see and hear? 4. What were the environmental conditions (weather, light, noise, etc.) at the time? 5. What was (were) the injured worker(s) doing at the time? 6. In your opinion, what caused the accident? 7. How might similar accidents be prevented in the future? ----14 WRITTEN REPORT: NOT FINISHED UNTIL THE PAPERWORK IS DONE The following outline has been found especially useful in developing the information to be included in the formal report: 1. Background Information a. Where and when the accident occurred b. Who and what were involved c. Operating personnel and other witnesses 2. Account of the accident (what happened?) a. Sequence of events b. Extent of damage c. Accident type d. Agency or source of energy or hazardous material 3. Discussion (analysis of the accident: how and why?) a. Direct causes (energy sources, hazardous materials) b. Indirect causes (unsafe acts and conditions) c. Basic causes (management policies, personal or environmental factors) 4. Recommendations (to prevent a recurrence) for immediate and long range action: a. Basic causes b. Indirect causes c. Direct causes (such as reduced quantities or protective equipment or structures) An inquiry that answers these and related questions will probably reveal conditions that are more open to correction than attempts to prevent carelessness. |
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