MEC232 Human & Equipment Safety - Topic 1 - PDF

MEC232 Human & Equipment Safety Ehab Abousaif, PhD Assistant Professor of Electrical Engineering – Faculty of Engineering Topic 1  Course aims Define human factor analysis, Recognize equipment safety and occupational safety, Design the workplace...

MEC232 Human & Equipment Safety Ehab Abousaif, PhD Assistant Professor of Electrical Engineering – Faculty of Engineering Topic 1  Course aims Define human factor analysis, Recognize equipment safety and occupational safety, Design the workplace so that they fit the people who use them, Define the term of Ergonomics, Describe the materials handling and safety culture, Recall Occupational Safety and Health Administration (OSHA) permissible limits, analyze the risk assessment, hazard identification, and risk estimation, and Diagnose accident prevention and Risk control. 2  Grade Distribution Assessment Measures Weight Course Grading Quizzes 20% Research project 10% Mid-term Exam 30% Final Exam 40% Total 100% T H E F U T U R E S T A R T S H E R E Concept of Occupational & Health Safety Who is responsible for the health and safety? Everyone is entitled to work in an environment where risks to their health and safety are properly controlled.  The Safety and Health Manager Everyone wants a safe and healthful workplace, but what each person is willing to do to achieve this worthwhile objective can vary greatly. As a result, the management of each firm must decide at what level along a broad spectrum, the safety and health effort will be aimed. The worker's behavior is the most important determinant for his/her safety, but behavior alone can not make a dangerous job safe. One person, usually designated as safety director or industrial hygienist, sets the tone of the safety and health program within a firm. (by posting motivational signs & complying statistics)  The year 1970 changed the history of worker safety and health in general and the safety manager’s role in particular. The landmark change that year was the pasage of the Occupational Safety and Health Act that created the federal Occupational Safety and Health Adminstratioin (OSHA). The field of occupational health has probably benefited even more from OSHA than has the field of occupational safety. OSHA designate the new job title of safety & health manager. The term manager envisions the enlarged scope of responsibility, which includes analysis of hazarads, compliance with standards, and capital investment planning, in addition to the conventional functions.  Information technology has made this task easier, and today’s safety and health manager can take advantage of the full test of OSHA standards on the Internet by accessing the OSHA website. Until the safety and health manager learns what hazarads a particular standard is intended to prevent, he/she will have a difficult time persuading either management or employees that a given situation needs correction.  A Reasonable Objective Any safety & health manager who feels that elimination of workplace hazards is an indisputable goal is naïve. In the real world, we must choose among the following: Ø Hazards that are physically infeasible to correct. Ø Hazards that are physically feasible, but are economically infeasible to correct. Ø Hazards that are both physically and economically feasible to correct. Hazards that are physically infeasible to correct. The airplane that took off from LaGuardia airport on January 15, 2009. During take-off, both engines were disabled by what is thought to have been birds entering the engine. This hazarad is currently impossible to eliminate because of the current mechanics of jet engines. However, millions of people fly every year, taking the risk. i.e. exposure of radiation during x-ray procedures. Although precuations are taken, it is impossible to completely eliminate exposure to undesired radiation (e.g.carrefour entrance) Hazards that are physicallly feasible, but are economically infeasible to correct. Consider crosswalks on a university campus. There is always the chance that someone will be struck by an automobile while in the crosswalk. The hazarad can be eliminated through constuction of elevated walkways, gates or other mechanisms. However, owing to the cost, inconvenience, and low probability of accident, these measures are reserved for the busiest of crosswalks.  G A L A L A U N I V E R S I T Y THE FUTURE STARTS HERE Hazarads that are both physically and economically feasible to correct. Technology has led to safety innovation in the auto industry, such as air bags and antilock brake, which are considered indispensable and included on every automobile. In reality, every hazarad must fall into one of these categories. It is unrealistic and naïve strategy to attempt to eliminate all hazards. To see that consider the following case study. T H E F U T U R E S T A R T S H E R E  G A L A L A U N I V E R S I T Y THE FUTURE STARTS HERE Some managers would accept that the safety and health rationale as all they need to begin action to correct the problems listed in the case study. But this would be a naïve response. More data are needed to decide what to do. While busying the plant maintenance department to correct the foregoing three problems (which may or may not be consequential), a serious electrocution or respiratory hazard may be going unchecked or may even unnoticed. Overreaction may also be deteriorating S&H manager’s credibility. The goal of this course, then is to assist the safety and health manager in: (1) detecting hazards and (2) deciding which ones are worth correcting Safety Versus It is essential that today’s safety and health Health manager give sufficient attention not only to safety hazards, but also to heath hazards. There is no question that machine guarding is a safety consideration, and that airborne asbestos is a health hazards. But some hazards- such as those associated with paint spray areas and welding operations- are not so easy to classify.  An acute effect is a sudden (short term) reaction to a severe condition; a chronic effect is a long-term Safety deals deterioration due to prolonged exposure to a milder with the acute adverse condition. (industrial noise, chemical exposure) effects of Industrial hygienists, those who concentrate on hazards, health hazards, are known by their sophisticated whereas instruments and scientific expertise. health deals with the Safety specialist, instead of being an expert with chronic effects precise scientific instruments, usually has more industrial process experience and practical job of hazards. knowledge.  Safety Versus Health There are probably more occupational health fatalities than safety, but the statistics will not reflect this difference because health fatalities are delayed and often are never diagnosed. Another problem with identifying health hazards is that the signs of occupational illness are often identical to common symptoms arising from normally occurring illnesses encountered off the job. For instance, a common cold causes respiratory congestion, headaches, and perhaps fever. These same symptoms could also be the result of dangerous exposure to a toxic chemical or other occupational hazard. The industrial hygienist is tasked with sorting out these symptoms and identifying occupational hazards to be controlled.  Role in The Corporate structure One role of the safety and health manager is as a liaison with government agencies, a condition brought about by the arrival of OSHA. A related field is consumer product safety. The Consumer Product Safety Commission (CPSC) is a federal agency whose enabling legislation is obviously patterned after OSHA’s. The laws of the two are remarkably similar. CPSC concentrates on the responsibility of the manufacturers of products, whereas OSHA concentrates on the responsibility of the employer.  A CASE STUDY In 1984, in a shocking disaster in Bhopal, India, at least 2,500 civilians were killed in a single industrial accidental release of deadly methyl isocyanate gas. This incident had an impact on public policy in the US. Because of its close relationship to worker safety and health, the responsibility for compliance with Environmental Protection Agency (EPA) requirements is often made a part of the duties of the safety and health manager.  In the first decade of the twenty-first century, an increased awareness of global warming raised public consciousness of threats to the environmental in general. Progressive legislation manadating “green engineering” was aimed at reducing the use of carbon fuels and their contribution to the global warming problem. Competence in these areas is proving to be a point of differentiation and competitive advantage for companies excelling in environmental protection. Resources at Hand Safety professionals should apply to: Board of Certified Safety Professionals of America, www.bcsp.org Health professionals should apply to : American Board of Industrial Hygiene, www.abih.org CSP for Certified Safety Profesional and CIH for Certified Industrial Hygienist. Professional Societies Two professional societies are foremost in the career field of occupational safety and health: ○ American Society of Safety Engineers (ASSE), www.asse.org ○ American Industrial Hygiene Association (AIHA), www.aiha.org Systems Safety Safety was considered something that could be achieved by being careful, but it did not require the kind of life-cycle planning and design that other aspects of the production process required. In mid-1950s, a movement began in the aerospace industry in California to consider safety as a system to be planned for and considered in every step of the process. System safety is considered essential in fields where an accident can be catasprophic, such as airlines, aerospace, and hospitals. Systme safety Society, www.system-safety.org Standards Institutes The age of OSHA enforcement has brought increased recognistion of the national standards-producting organizations. The following are the most prominet among these organizations: ○ American National Standards Institute (ANSI), www.ansi.org ○ National Fire Protection Association (NFPA), www.ngpa.org ○ American Society of Mechanical Engineers (ASME), www.asme.org ○ American Society for Testing and Materials, (ASTM) www.astm.org Government Agencies The national institute for Occupational Safety and Health (NIOSH) has a wealth of research data on the hazards of specific materials and processes. NIOSH uses these data to write criteria for recommended new standards. www.niosh.gov OSHA itself is of value to be the safety and health manger seeking information. Thank You gu.edu.eg MEC232 Human & Equipment Safety Ehab Abousaif, PhD Assistant Professor of Electrical Engineering – Faculty of Engineering Topic 2  Development of the Safety and Health Function Workers’ Compensation One of the first questions that arises when one begins to study the field of industrial safety and health is “Who should be responsible when a worker is injured?” - Many would answer, “The employer – because the employer gave rise to the job and will profit from the production.” However, the problem is not that simple. The problem of compensation to injured employees was first addressed as a societal problem in Europe, and the idea was soon taken up in the United States and Canada. 2  The first laws were introduced in state legislatures in 1909 and were known as workmen’s compensation laws. Soon, all states in the United States had such laws. About 50 years later, the name changed to “workers’ compensation laws” to remove the gender designation for “workers.” Gross negligence refers to a person's conduct where an act or failure to act creates an unreasonable risk of harm to another because of the person's failure to exercise slight care or diligence. 3 4  Recordkeeping Forms, reports, and recordkeeping make up no small part of the safety and health manager’s job. According to the National Safety Council (NSC), “Just one OSHA data sheet takes U.S. safety managers a cumulative 54 million hours a year to complete. That’s just one of dozens of forms (the safety manager) may be responsible for” (National Safety Council, 1995). In addition, the safety manager must keep up with the latest developments, including changes to rules and procedures. 5  The recording of worker fatalities is more consistent than that of injuries and illnesses; thus, fatality statistics can be used to observe trends both before and after federal regulation. 6  Traditional Indexes Familiar statistical measures are frequency and severity, which were defined by the old system. - Frequency measured the number of cases per standard quantity of work hours. - Severity measured the total impact of these cases in terms of “lost workdays” per standard quantity of work hours. 7  Incidence Rates First aid is not considered medical treatment even if it is administered by a physician. Regardless of treatment, the injury is required to be recorded. To compute the incidence rate, the number of injuries is divided by the number of hours worked during the period covered by the study. The value obtained is then multiplied by a standard factor to make the rate more understandable. 8  A full-time worker typically works approximately 50 weeks per year at 40 hours per week. Thus, the number of hours worked per year per worker is approximately 9 The term ‘incidence rate’ is really a general term and includes the following: - Total-Recordable-Cases (TRC): Counts all recordable injury and illness cases, except fatalities. - Lost-WorkDay-cases Incidence rate (LWDI): Counts injury (excludes illness) cases involving “lost workdays,” which includes restricted work activity days. Fatalities are not included. - Days Away, Restricted, or Transferred Rate (DART): Counts injury and illness cases involving days away from work, restricted work activity, and transfer to another job. Fatalities are not included. 10 Cont. - Number-of-Lost Workdays rate: Counts the number of “lost workdays”, including restricted work activity days. Fatalities are not included. - Injury incidence rate: Counts the total number of injury cases. - Illness incidence rate: Counts total number of illness cases. - Fatality incidence rate: Counts total number of fatalities. - Specific-hazard incidence rate: Counts cases in which only a specific hazard results in injury or illness. 11 Recordkeeping Forms OSHA’s Form 300 12 Recordkeeping Forms OSHA’s Form 300A 13 Recordkeeping Forms OSHA’s Form 301 Within 7 calendar days after you receive information that a recordable work-related injury or illness has occurred, you must fill out this form or an equivalent. According to Public Law 91- 596 and 29 CFR 1904, OSHA’s recordkeeping rule, you must keep this form on file for 5 years following the year to which it pertains. 14 A case study 15 To complete OSHA 300, you need to analyze each case as follows: 16 17 18 19 20 21 22 23 24 25 26 Calculation of Incidence Rates 5 X 200,000 TRC = 2_0 250 X 2000 2 X 200,000 DART 1.2 250 X 2000 2 X 200,000 DAFWII 0.8 250 X 2000 2 X 2000,000 LWDI (injuries only) 0.8 250 X 2000 3 X 200,000 Injury incidence rate 1.2 250 X 2000 2 X 200,000 Illness incidence rate = 0_8 250 X 2000 1 X 200,000 Fatality incidence rate 0.4 250 X 2000 36 X 200,000 Number-of-lost-workdays rate 14.4 250 X 2000 1 X 200,000 Specific-hazard incidence rate (eye injuries) 0.4 250 X 2000 27 Thank You gu.edu.eg MEC232 Human & Equipment Safety Ehab Abousaif, PhD Assistant Professor of Electrical Engineering – Faculty of Engineering Topic 3  Definitions of Ergonomics ‘‘Ergonomics’’ is based on two Greek words: ergos, meaning work, and nomos, meaning the study of or the principles of. In other words, ergonomics refers to the study of work. Ergonomics is the discipline of examining the capabilities and limitations of people. Ergonomics, as defined by the International Ergonomic Association, is the scientific discipline concerned with the understanding of interactions among humans and other elements of a system, and the profession that applies theory, principles, data, and methods to design in order to optimize human well-being and overall system performance. 2  Ergonomics and safety management Ergonomics is a multidisciplinary science that studies human physical and psychological capabilities and limitations. This body of knowledge can be used to design or modify the workplace, equipment, products, or work procedures to improve human performance and reduce the likelihood of injury and illness. The branch of engineering science in which biological science is used to study the relationship between workers and their environment. The study of human capability and psychology in relation to the working environment and the equipment operated by the worker. 3  How is Ergonomics Related to Safety? When the principles of ergonomics are applied in the context of workplace safety, the concept of ergonomic safety is born. Ergonomics safety ensures that the products, methods, and environment that a worker uses are appropriate to fit the worker’s job requirements and personal capabilities. 4  How did Ergonomics Safety develop? The practice of ergonomics safety principles can be possibly traced back to the early Egyptian, Greek, and Roman dynasties, where findings have shown that tools and other manmade devices (e.g. pulleys, wheels) were created to minimize workload. Fast forward to the aftermath of the Industrial Revolution, people began developing factory machinery with some design principles closer to how we practice modern ergonomics. In 1857, Wojciech Jastrzebowski, a Polish scholar, then coined the term ‘ergonomics’ – which comes from the Greek words ergon (work or labor) and nomos (natural laws) – in his publication. 5  The modern principles of ergonomics safety became more prevalent during World War II as interest in logical human- machine interaction grew and military equipment, machinery, and weaponry became more complex. Human factors need to be taken into account to ensure that these advanced systems are to be operated safely. When World War II concluded, research on ergonomics and safety continued to expand as more and more technological advancements were introduced. Perhaps the most noteworthy development in modern ergonomics safety happened in the field of human-computer interaction, brought on by the explosion of computer usage in the workplace and, soon after, the home. 6 Why is Ergonomics Important in Workplace Safety? Ergonomic disorders are the fastest-growing category of work- related illness. According to the most recent statistics from the U.S. Bureau of Labor Statistics, they account for 56-63 percent of illnesses reported to OSHA. Further, around two million work- related musculoskeletal disorders (MSDs) also occur yearly in the United States alone. Many of these are caused by ergonomic work-related injuries like carpal tunnel syndrome alone, tendinitis, rotator cuff injuries, muscle strains, and low back injuries due to risk factors like high task repetition, forceful exertions, and repetitive awkward postures. 7 What are the Benefits of Ergonomics? The implementation of ergonomics safety as part of the workplace safety program helps ensure that employees’ capabilities and physical limitations are matched with the right tools and working spaces to ensure comfortable and safe working conditions for them. The benefits of an ergonomics safety program can not only make an impact on the lives of employees, but it can also make a difference in the overall efficiency of the entire organization. Here are some of the most notable benefits of ergonomic safety in the workplace: (1) Helps reduce costs: By systematically reducing ergonomic risk factors, you can prevent costly MSDs. With approximately $1 out of every $3 in workers’ compensation costs attributed to MSDs, this represents an opportunity for significant cost savings. (2) Helps prevent other incidents and injuries: Workers who experience discomfort on the job may find shortcuts or workarounds that could result in incidents and injuries such as slips, falls, and lacerations. Implementing an ergonomics program and encouraging workers to report ergonomic issues early helps prevent MSDs as well as other common workplace incidents. 8 (3) Improves overall productivity: Healthy employees are your most valuable asset; creating and fostering the safety & health culture at your company will lead to improved productivity for your organization. Effective ergonomic safety programs can promote good posture at all times, less exertion, fewer motions, and better heights and reaches, thus helping employees to work more comfortably and efficiently in their workstations. (4) Helps foster employee engagement and satisfaction: Employees notice when the company is putting forth its best efforts to ensure their health and safety. It shows your company’s commitment to safety and health as a core value. If an employee does not experience fatigue and discomfort during their workday, it can reduce turnover, decrease absenteeism, improve morale, and increase employee involvement. 9  A case study Employees at a small facility were experiencing a high frequency of back injuries while manufacturing and finishing air compressor tanks. Faced with the prospect of losing compensation insurance coverage, it contacted a Certified Professional Ergonomist (CPE) to conduct an analysis of the workplace. Body motion Activity frequency and duration Pace issues Lifting-related risk factors 10 Ergonomics involves knowledge of sociology, psychology, anthropology, anatomy, physiology, chemistry, physics, mechanics, statistics, industrial engineering, biomechanics, and anthropometry. 11 What are the objectives of Ergonomists? The primary objective of ergonomics is the improvement of human health, safety, and performance through the application of sound people and workplace principles. The goal is to help production managers improve productivity and efficiency. Ergonomists can best serve as part of a team including engineers, managers, and medical personnel. The ergonomics team will systematically analyze the job requirements from a worker’s capability and limitation perspective, analyze workplace layout and design, and recommend improvement of the production process. The goal is to eliminate problems before they occur. 12  Applying Ergonomics: An overview The triad of recognition, evaluation, and control. Recognition of ergonomic hazards usually involves the search for symptoms. Evaluation implies the collection of information to help determine the extent and location of the problem. (OSHA form 300 &300A) Engineering controls, such as the design and utilization of ergonomically correct workstation and workplace layouts. (These include job rotation or requiring employees to perform several different jobs during a shift to reduce repetition in a task.) 13 Applying Ergonomics Operator-machine system analysis examines factors associated with the people; equipment/machinery, including the layout of the workplace; and environment. It provides safety professionals with a systematic procedure to study the three categories of causes resulting in ergonomic hazards in the occupational setting: people, machines, and the environment. 14  People Variables The people or operator variables associated with a system are composed of the human factors contributing to the ergonomic problem. (physiological dimensions, capabilities, and limitations) Examination of mental and physical job demands is done to determine whether job demands exceed human capabilities. Knowledge of human physiological dimensions (anthropometry) and movement (biomechanics) is a critical component. A quantitative evaluation of motions, forces, or other contributing factors can then be performed. 15  How to Spot and Correct Ergonomic Hazards Here are some general ergonomic safety tips to help prevent the most prevalent ergonomic hazards: (1) When transporting and handling: Be knowledgeable about body limitations. Provide carts for transporting materials to eliminate lifting. Require all loads to be labeled with their weight. When lifting, keep your back straight and lift with your legs. Assign two or more staff to lift heavy objects depending on weight. Lift slowly and carefully. Don’t twist or turn your spine while carrying the load. Use shoulder pads to cushion loads carried on the shoulder. Use knee pads for kneeling tasks. Store materials at waist height to minimize reaching. Design containers with handles for easy gripping. 16 (2) Workstation improvements: Redesign workstations to eliminate awkward postures. Provide adjustable equipment that can be used by workers to allow neutral postures. Maintain good body posture (3) Staff scheduling and training: Rotate workers among different tasks to avoid repetitive motions. Improve the work schedule to minimize excessive overtime that causes fatigue. Increase staff to reduce individual workloads. Provide sufficient employee breaks. Adequate recovery time can reduce fatigue. Provide workers with training on ergonomics policies and procedures. 17 Thank You gu.edu.eg MEC232 Human & Equipment Safety Ehab Abousaif, PhD Assistant Professor of Electrical Engineering – Faculty of Engineering Topic 4  Personal protective equipment (PPE) The need for personal protection implies that hazards have not been eliminated or controlled. The need for first aid implies something even worse! When feasible, engineering control of the hazard is preferred over the use of personal protective equipment (PPE). We realize that some risks will always remain; our goal is to eliminate unreasonable risks, not all risks. The job of improving safety and health in the workplace will never be completely finished; so we must concern ourselves with the need to provide personal protection against hazards that have not been completely eliminated and to provide first aid when an accident does occur. Hierarchy of controls Personal protective equipment (PPE) - The basic premise of enforcement authorities is that if personal protective equipment (PPE) is needed, then the employees must be trained to use it properly. - Employees need to know when PPE is necessary, what kinds of PPE are required, and how to wear it effectively, to avoid developing a false sense of security. - If either the workplace changes or the PPE changes, the employer must take a responsible position and retrain the employee if necessary. - Both the initial training and the retraining must be documented with a certificate that identifies the names of employees trained, the dates, and the subject for which the employee is certified.  Protecting employees from workplace hazards Employers must protect employees from workplace hazards and dangerous work procedures that can cause injury, illness, and fatalities. Employers must: - Use all feasible engineering and work practice controls to eliminate and reduce hazards. - Then use appropriate PPE if these controls do not eliminate hazards. - Remember: PPE is the last control.  Hearing Protection The most important factor in selecting a type of noise protection is probably effectiveness in reducing the decibel level of noise exposure. However, this is by no means the only important factor, and selection can be somewhat complicated. Economics is always a factor, and if limited effectiveness is all that is necessary in a given situation, cheaper devices can be selected. Employee comfort is probably at least as important a factor as economics. The worker comfort factor goes beyond the simple goal of promoting worker satisfaction; it affects the amount of protection the worker will receive. If workers find a type of ear protection uncomfortable or awkward to wear, they will use every excuse not to wear it, which results in loss of protection. Sound levels and their relevance Cotton Balls: Ordinary cotton balls, without the addition of a sealing material, are virtually worthless as a means of personal protection from noise. Swedish Wool: Similar in feel to cotton, Swedish wool is a mineral fiber that has much better attenuation values than cotton. Swedish wool is somewhat effective, but is much more effective when impregnated with wax to make a better seal. One problem with Swedish wool is that it can tear when it is pulled out. To alleviate this problem, Swedish wool sometimes comes in a small plastic wrapper that is inserted with the wool. Swedish wool can be considered only fairly reusable; reuse will depend on personal hygiene, quantity of earwax, and worker preference. Earplugs The most popular type of personal protection for hearing is the inexpensive rubber, plastic, or foam earplug. Earplugs are practical from the standpoint of being easily cleaned and reusable. Workers often prefer earplugs because they are not as visible as muffs or other devices worn external to the ear. However, within this advantage lies a pitfall: Workers may be more complacent about using the earplugs when it is not immediately obvious to the supervisor whether the earplugs are being worn. The noise attenuation for properly fitted earplugs is fairly good, falling somewhere between that of Swedish wool and the more effective earmuffs. Molded Ear Caps Some ear protectors form the seal on the external portion of the ear by means of a mold to conform to the external ear and a small plug. Since human ear shapes vary so widely, fit is a problem. Molded ear caps are more visible than earplugs, which has both advantages and disadvantages, as discussed earlier. Molded ear caps may be more comfortable to the wearer, but are more expensive than earplugs. Earmuffs Earmuffs are larger, generally more expensive, and more conspicuous than Swedish wool, plugs, or caps, but they can have considerably better attenuation properties. The attenuation capability depends on design, and more variety in design is possible with earmuffs. Although some workers object to wearing conspicuous earmuffs, some workers prefer them, stating that they are more comfortable than earplugs. Helmets The most severe noise-exposure problems may force the safety and health manager to consider helmets for personal protection against noise. Helmets are capable not only of sealing the ear from noise, but also of shielding the skull bone structure from sound vibrations that can be transmitted to the ear as noise. Helmets are the most expensive form of hearing protection but have the potential to offer protection from a combination of hazards. Properly designed, the helmet can act as a hard hat and a hearing protector at the same time. It must be remembered that fit is very important for all types of hearing protectors. As in noise enclosures or sound barriers, the material itself might have excellent sound- attenuation properties, but if there is a leak or crack, most of the effectiveness of the device is lost. Eye and face protection The use of safety glasses has become so widespread and so many different styles are now available that many safety and health managers have established a rule that the safety glasses must be worn throughout the plant. A general custom in industry is to require visitors to wear safety glasses during plant tours. There is a difference between street safety glasses and industrial safety glasses. Visitors or employees who claim that their prescription glasses are “safety glasses” probably mean that they have street safety lenses. Industrial safety lenses must pass much more severe tests to meet the American National Standards Institute (ANSI) standards.  Machining operations that produce chips or sparks are almost universally conceded to necessitate the use of eye protection. Notable among these operations are those of grinding machines, drill presses, and lathes. Both metal and wood materials can produce dangerous eye hazards when machined. Corrosive liquids or other dangerous chemicals also represent eye hazards when poured, brushed, or otherwise handled in the open. When working with such materials, face protection may be needed in addition to eye protection.  Workers must wear personal protective equipment over the eyes or face, when the job requires it, regardless of whether they are wearing contact lenses. In OSHA’s early years rules were observed that prohibited the use of contact lenses in certain jobs. Later research led OSHA to remove these prohibitions and permit contact lens users to wear them on the job, provided appropriate personal protective equipment is used as required for nonusers of contact lenses as well. Contact lenses have some advantages over conventional glasses (with frames). The frames of conventional glasses may partially restrict the field of view and may interfere with the seal required for full- face respirators.  Is it Easy or Just an Illusion ? The problem of providing personal protective equipment seems straightforward and easy enough to understand. However, the simplicity of the problem is an illusion, and many industrial safety and health managers fall into its trap. For instance, it would seem that if the noise level in the production area is too high, the solution to the problem would be to provide ear protection for the workers. However, anyone who has actually confronted this problem knows that the solution is not that simple. For a variety of reasons, many people do not want to wear ear protection. They may be shy about the appearance of ear protection equipment, they may feel discomfort or perhaps even pain, they may feel it interferes with their necessary hearing or efficiency, or they may feel that the use of personal protective equipment is their own business, not their employer’s.  The matter of personal protective equipment becomes very delicate when employees bring their own equipment to work. If the equipment is not properly maintained, who is responsible—employer or employee? - OSHA’s position is that the employer is responsible. As a safety and health manager, consider the following logic: If employees bring their own personal protective equipment to work, is it not possible that the equipment itself could represent a hazard? Personal protective equipment must be properly selected to match the hazard, and employees bringing their own equipment might falsely think they are safe when their equipment could actually be malfunctioning or inappropriate.  Respiratory protection Of even more vital importance than eye and hearing protection is the need for respiratory protection from airborne contaminants. Particularly hazardous atmospheres may be referred to as IDL, which stands for “immediately dangerous to life” or IDLH, which stands for “immediately dangerous to life or health.” Recently, the acronym IDLH has become more widely used. If a single acute exposure is expected to result in death, the atmosphere is said to be IDL. If a single acute exposure is expected to result in irreversible damage to health, the atmosphere is said to be IDLH. Some materials (e.g., hydrogen fluoride gas and cadmium vapor), for example, may produce immediate transient effects that, even if severe, may pass without medical attention but are followed by sudden, possibly fatal collapse 12 to 72 hours after exposure. The victim “feels normal” after recovery from transient effects until collapse. A classification of the various devices is in order. The two major classifications are: (1) Air-purifying devices versus (2) Atmosphere-supplying devices Atmosphere-supplying respirators provide clean breathing air from a source separate from the work area. These respirators protect wearers from many types of contaminants (particles, gases, and vapors). In some cases, they can also supply breathable air in places that do not have enough oxygen. Fit testing is required for respirators with a tight-fitting facepiece. Respirator Plan OSHA standard 1910.134(c) sets forth these necessary steps, summarized here as follows: 1. Procedures for respirator selection 2. Medical evaluations for respirator users—Personnel Screening 3. Respirator fit testing 4. Procedures for proper use of respirators 5. Procedures for respirator maintenance 6. Provision of adequate supplied breathing air for air-supplying respirators 7. Employee training for when respirators are needed 8. Employee training for proper wearing, use, and maintenance of respirators 9. Procedures for continuing evaluation of the respirator program  Head protection Hard-hat rules should be carefully formulated with ample consideration for the consequences both ways. Once it has been decided that a hard hat rule is necessary, the safety and health manager should take steps to ensure its implementation. The evidence that was used to prove the need for the hard-hat rule should be compiled into an organized training package to convince workers. After the training and launching of the implementation phase, follow-up checks should be used to ensure that the rule is being followed. Corrective steps should be taken to overcome individual violations of the rule, including disciplinary actions if necessary. Hard hats seem to have won wider acceptance than hearing protection. Besides being a symbol for occupational safety and health, the hard hat has become a symbol for rugged, physical jobs. This image has appealed to males for centuries and is becoming an increasingly appealing image for female workers as well.  Safety shoes (steel-toe shoes) Safety shoes are a more expensive undertaking than hard hats because safety shoes get worn out faster and are more expensive per item. Employees may buy their own shoes at attractive discounts in some arrangements, and this encourages actual use. Safety shoes come in a wide variety of appealing styles, and employee resistance to wearing safety shoes is largely a thing of the past. The safety and health manager is usually saddled with the decision as to which jobs require safety shoes and which do not. Although applicable national standards are explicit about the design and construction of safety shoes, as with almost all personal protective equipment, the decision of where such shoes must be worn is left up to either the user or management. One place where safety shoes are clearly needed is on shipping and receiving docks. This should be obvious, but there has been some legal controversy over this issue.  Protective Clothing and Skin Hazards Occupational skin disease, especially contact dermatitis from irritants to the skin, represents a significant number of all occupational diseases reported. The safety and health manager should be alert to several skin hazard sources, such as welding, special chemicals, open-surface tanks, cutting oils, and solvents. Most welders know the value of heavy-duty protective aprons and flameproof gauntlet gloves. Leather or woolen clothing is more protective than cotton from a burn ability standpoint. Nomex™ is a treated flame- retardant fabric.  Another concern for protective clothing is chemical exposures from open-surface tanks. Gloves must be impervious to and unaffected by the liquid being handled and long enough to prevent the liquid from getting inside. If the gloves are not long enough, they can be more hazardous than beneficial. Many workers’ hands have become more irritated than their unprotected arms simply because the gloves they were wearing permitted liquids to get inside, turning the gloves themselves into dip tanks for the hands!  First aid The safety and health manager will frequently be responsible for the first-aid station and may supervise a plant nurse. The first-aid station may satisfy several additional functions besides providing immediate care for the injured. The first-aid station is often used for medical tests, screening examinations, and monitoring of acute and chronic effects of health hazards. Also, the plant nurse or other first-aid personnel may be responsible for performing some of the recordkeeping and reporting functions discussed in previous lectures. One adequately trained first-aid person is required in the absence of an infirmary, clinic, or hospital “in near proximity” to the workplace. The interpretation has sometimes depended on whether the route to the hospital crosses a railroad track If the workplace is not itself a hospital or clinic or is not directly adjacent to one, the safety and health manager is advised to be sure that at least one, preferably more than one, employee is adequately trained in first aid.  A first-aid kit or first-aid supplies should be on hand, and the safety and health manager should seek a physician’s advice regarding the selection of these materials. Unfortunately, medical doctors are hesitant to give such advice, probably because they fear subsequent involvement in litigation should an accident occur for which adequate materials are not available. Safety and health managers should do their best to obtain such advice and then document what was done to obtain information. Another first-aid consideration is the provision of emergency showers and emergency eyewash stations on job sites where injurious corrosive material exposure is a possibility. Almost everyone has seen the deluge-type shower, which is activated by grabbing and pulling a large ring attached to a chain that activates the valve. Eyewash facilities are similar to a drinking water fountain in which two jets are provided, one for each eye. Thank You gu.edu.eg MEC232 Human & Equipment Safety Ehab Abousaif, PhD Assistant Professor of Electrical Engineering – Faculty of Engineering Topic 5 Fire Protection It is easy to oversimplify fire protection as meaning only fire extinguishment, but it encompasses three fields: - Fire prevention, - Fire suppression, - Personal protection (escape). The fire itself has three ingredients: oxygen, heat, and fuel, as shown in the familiar fire triangle. By keeping in mind these three essential physical ingredients of fire, strategies for prevention and suppression can be developed for various industrial circumstances. 1  Fire Prevention Effective fire prevention requires anticipation of fire sources. Each facility is different and requires an individual analysis of potential fire sources. A principal cause of industrial fires is overheated bearings or hot machinery and processes. Another cause is clogged or dirty ventilation filters or ducts, especially when the clogging material is a flammable or combustible air contaminant. Another component in a fire prevention plan is a strategy for housekeeping. Accumulation of combustible dusts in grain elevators and paint residues in spray painting operations are good examples of how poor housekeeping can contribute to fire hazards. 2  Emergency Evacuation Using the escape strategy for dealing with fires or other emergencies, the employer must prepare a written emergency action plan. The emergency action plan concept has been around for many years for hospitals, schools, and institutions, and more recently, has been extended to industries in general. It is crucial to an emergency action plan is an employee alarm system. However, alarm systems are not as simple as they may seem. There are searching questions that must be asked: - Will persons recognize the signal as a fire alarm? - What about deaf or blind employees? Audible, visual, and tactile systems must be considered, or perhaps combinations of these systems. 3  Employee Fitness Volunteering to join the fire brigade is not sufficient to qualify the worker to fight fires. Conditions that may be hazardous include heart disease, epilepsy, or emphysema. Other conditions, such as ruptured eardrums or the wearing of a beard, may make the use of respiratory equipment ill advised. The safety and health manager should be sure that the fire brigade volunteers are screened, and a physician’s certificate may be necessary for questionable cases. Volunteers unfit for interior structural firefighting may be used in other tasks. 4  Firefighter Training Many places have fire training academies, and safety and health managers should find out what schools and academies are available for their fire brigade members. Interior structural firefighting is more demanding, and fire brigade members assigned to such tasks should be trained at least quarterly. Other fire brigade members should be trained at least annually. Also, firefighting equipment to be used by the fire brigade should be inspected annually, and fire extinguishers should be inspected monthly. 5 6  Fire extinguishers Fire extinguishers are still the most effective method of immediately controlling a very local fire before disastrous consequences ensue. The safety and health manager needs to understand the various fire classes and the type of extinguishers appropriate for each class. A fire extinguisher is a handheld active fire protection device usually filled with a dry or wet chemical used to extinguish or control small fires, often in emergencies. Typically, a fire extinguisher consists of a hand-held cylindrical pressure vessel containing an agent that can be discharged to extinguish a fire. Fire extinguishers manufactured with non-cylindrical pressure vessels also exist but are less common. 7 Fire Classes 8  Inspection, Testing, and Mounting In addition to the monthly and annual inspections, fire extinguishers must receive a hydrostatic test according to a prescribed test schedule. Fire extinguisher shells deteriorate from mechanical damage or corrosion and may be unsafe for containing pressures inside. The hydrostatic test places the extinguisher under a test pressure to determine whether it can safely contain the pressures to which it will be subjected in use. The test has technical specifications and must be done by a trained person using suitable equipment and facilities. The safety and health manager invariably leaves the hydrostatic tests for the professional fire extinguisher service to perform. 9  Training and Education A facility looks well equipped and protected when fire extinguishers are placed about the workplace, readily accessible for use in an emergency. However, the appalling reality is that few employees know how to use a fire extinguisher effectively, and some would even be afraid to use the extinguishers if they knew how. This is especially true of fire extinguishers or hose systems located behind glass doors. For most people, there is a great reluctance to break glass even in an emergency. 10 Automatic Sprinkler System Automatic sprinkler systems present a paradox because they affect employee safety, but are usually installed principally to protect property and to lower insurance rates. If a spray area is protected by an automatic sprinkler system, a good way to protect the sprinkler heads is to cover them with paper bags. If a fire does occur, the paper bags will either burn away or be washed away by the water spray so that they do not interfere with the fire suppression action of the sprinklers. Another error with automatic sprinklers is to stack material too close to the ceiling. This interferes with the distribution of spray from the sprinkler head. 11  Dry Chemical Systems Dry chemicals used for extinguishing agents are usually not dangerous to the health or safety of personnel. However, the actual distribution of the chemical powder during an emergency may obscure vision, preventing escape. The biggest problem with dry chemical systems is the caking or lumping of the agent. Humid climates or moisture-producing processes subject the system to a greater risk of caking. Caking can render a dry chemical useless, so the chemical should be sampled annually to be certain that moisture is not causing caking. 12  Electrocution Hazards The first step toward safety from electrocution is to overcome the myth that “ordinary 110-volt circuits are safe.” The truth is that ordinary 110-volt circuits can easily kill, and actually do kill, many more people than do 220- or 440-volt circuits, which nearly everyone respects. However, the myth about 110 volts persists because almost everyone has sustained an electrical shock around the home or on the job without serious injury. It is true that some persons are more resistant to electrocution hazards than others, but a far more important factor is the set of conditions surrounding the accident. Wet or damp locations are known to be hazardous, but even body perspiration can provide the dampness that can make electrical contact fatal. Another important condition is the point of contact. If current flow enters the body through the fingers and passes out through a contact at the elbow, no vital organs receive direct exposure. However, if the flow is from a hand through the body to the feet, vital organs such as the heart, chest muscles, and diaphragm are affected, with possibly fatal results. 13 Ohm’s law 15  Human skin, if it is dry enough, is a good insulator and may have a resistance of 100,000 ohms or more. By using Ohm’s law, a 110-volt exposure would result in only a tiny current: It can be seen that such a tiny current will probably not even be noticed. However, add perspiration or any other moisture to the skin, and the resistance drops sharply. Owing to perspiration alone, the skin resistance can be reduced 200 times, to a level of about 500 ohms, with good contact with the electrical conductor. Once inside the body, the electrical resistance is very low and the current flows. If the total resistance in the circuit is only 500 ohms, the current is calculated as: From Figure 17.1 it can be seen that an alternating current at this level passing through the body, including the heart, will most likely be fatal. 16 Grounding A requirement for electrical current to flow is that its path makes a complete loop from the source of electrical power through the circuit and back again to the power source. 17 Wiring A typical 110-volt circuit has three wires: hot, neutral, and ground. Sometimes the neutral is called the “grounded” conductor, in which case the ground is called the “grounding” conductor. The purpose of the hot wire (usually a black insulated wire) is to provide contact between the power source and the device (load) that uses it. The neutral (usually a white insulated wire) completes the circuit by connecting the load with ground. Both the hot and the neutral normally carry the same amount of current, but the hot is at an effective voltage of 110 volts with respect to ground, whereas the neutral is at a voltage of nearly zero with respect to the ground. The third wire is the ground wire and is usually either green or is simply a bare wire. The purpose of the ground wire is safety.  Fire Hazards Most people think of electrocution when they think of electrical safety, but electrical codes have as much to do with fire hazards as they do with electrocution. Many systems, such as fuses or circuit breakers, protect against both fire and electrocution, but their primary function is fire prevention. 19 Wire fires One of the most common causes of electrical fires is wires that become overheated because they conduct too much current. Wire diameters (gauges) must be properly sized to handle the expected current load, and overcurrent protection (fuses or breakers) must ensure that these loads are not exceeded. Arc & sparks Whenever two conductors make a physical contact to complete a circuit, a tiny (or not so tiny) electric arc jumps the air gap just prior to contact. This arc may be so small as to be undetectable, but it is usually hot enough to ignite explosive vapors or dusts within their dangerous concentration ranges. 21 Electrical Sockets & plugs 22 Thank You gu.edu.eg MEC232 Human & Equipment Safety Ehab Abousaif, PhD Assistant Professor of Electrical Engineering – Faculty of Engineering Topic 6  X-ray radiation X-ray is a high-energy electromagnetic radiation. In many languages, it is referred to as Röntgen radiation, after the German scientist Wilhelm Conrad Röntgen, who discovered it in 1895 and named it X-radiation to signify an unknown type of radiation. X-ray wavelengths are shorter than those of UV rays and longer than those of gamma rays. There is no universally accepted, strict definition of the bounds of the X-ray band. Roughly, X-rays have a wavelength ranging from 10 nanometers to 10 picometers, corresponding to frequencies in the range 30 petahertz to 30 exahertz (3×1016 Hz to 3×1019 Hz) and energies in the range 100 eV to 100 keV, respectively. X-rays are widely used in medical diagnostics (e.g., checking for broken bones) and material science (e.g., identification of some chemical elements and detecting weak points in construction materials). 1 Radiation shielding 2  Radiation protection in diagnostic interventional radiology Employers must ensure for all workers that: Occupational dose limits are not exceeded, Protection and safety are optimized, Suitable and adequate facilities, equipment, and services for protection are provided, Appropriate monitoring equipment and personal protective equipment are provided and properly used, Appropriate training is provided as well as periodic retraining and updating, Adequate records are maintained, and A safety culture is provided 3 Workers must: follow any applicable rules for protection, Use properly the monitoring devices and personal protective equipment, and co-operate with the employer with respect to protection and safety. 4  Dose limits for occupational exposure Dose limits are set to protect workers and members of the public from the effects of ionizing radiation. They are set at a level that reduces the risk of serious effects occurring, such as cancer, and are in place to protect the eyes, skin, and extremities against other forms of damage, from exposure with the benefits of using ionizing radiation. The sievert is a unit of radiation exposure dose that a person receives and is used with regard to what is exposed to radiation, i.e. the human body. It is a derived unit of ionizing radiation dose in the (international system of units) and is a measure of the health effect of low levels of ionizing radiation on the human body 5  Dose limits and optimization of protection ALARA stands for “as low as reasonably achievable”. This principle means that even if it is a small dose, if receiving that dose has no direct benefit, you should try to avoid it. To do this, you can use three basic protective measures in radiation safety: time, distance, and shielding. 6  Special arrangements Pregnant workers A female worker should, on becoming aware that she is pregnant, notify the employer. The notification of pregnancy must not be considered a reason to exclude a female worker from work. The employer then must adapt the working conditions in respect of occupational exposure. To ensure that the embryo or fetus is afforded the same broad level of protection as a member of the public (Embryo dose < 1 mSv) 7 Classification areas in a radiology facility: Controlled areas All X-ray rooms (radiography, fluoroscopy, CT, mammography, interventional, etc.), including control rooms Physically delineated Warning signage Restricted access – physically & administratively Supervised areas A supervised area is defined as any area not designated as a controlled area, but in which occupational exposure conditions are kept under review even though specific protective measures and safety provisions are not normally needed. The areas will be designated with the careful evaluation of the dose rate in the particular areas. Areas where mobile radiography takes place. Public (uncontrolled) areas (public dose limits) Waiting rooms, toilets, corridors, stairwells, etc 8 Who can enter a controlled area? Entrance into controlled areas is strictly controlled by the employer. Employees designated as 'classified persons' and outside workers can enter the area where they have been authorized to do so by the employer and have received appropriate training. If an assessment of the potential exposure shows that work in a controlled area could be done by employees who are not classified persons, suitable written arrangements and monitoring would be required to ensure exposures are kept as low as possible. Other workers should only be allowed conditional access and only in accordance with prior written arrangements. 9 What is a classified person? An employer must classify an employee where they consider that their employee is likely to receive: - an effective dose greater than 6 mSv per year or - an equivalent dose greater than 15mSv per year for the lens of the eye or - a dose greater than 150mSv per year for the skin or the extremities (hands, forearms, feet or ankles) - Employees can only be classified if they are aged 18 years or over. What happens if I am 'classified’? As a classified person, your employer is required to: - inform you that you are classified - assess and record your radiation dose - ensure that you are certified fit to work with ionizing radiation by an appointed doctor or employment medical adviser (medical surveillance) - Your employer should periodically review if there is a continuing need for classification. 10  Primary Beam and Scatter Radiation Primary Beam The primary beam is a significant hazard, even very short exposure times can result in severe radiation burns. Scatter radiation It is produced when the primary beam interacts with samples and structures in the x- ray enclosure. Scatter radiation is a hazard near the sample. Leakage radiation from the X-ray tube is very low and not hazardous when the tube housing is intact. 11  Working with x-rays Primary beam the x-ray tube Scatter the patient When working with X-rays: Avoid the primary beam Minimize exposure to scatter 12 Scatter - distance Scatter decreases approximately by the inverse square law Stand as far away from the patient when x-rays are being produced 13 Scatter – time Minimize the time spent in areas where scatter is present Only be in the X-ray room if required to be Minimize the “beam on” time in fluoroscopy & interventional procedures 14 Scatter – shielding Shielding in walls, doors, windows, ceilings, floors Permanent operator barriers Personal protective equipment Movable barriers 15  Biological effects of radiation exposure Radiation is one of the best-investigated hazardous agents. Radiation levels can be readily controlled and monitored so work may continue at a level of risk that is much less than with many other technologies. The following slides present topics essential for working safely with radiation: Radiation dose units Acute vs. chronic radiation exposure Effects of radiation exposure –radiation burns –radiation sickness –long-term effects of exposure to radiation Radiation Dose Limits General Radiation Safety 16 Why are different units used to measure exposure to radiation? 17 Acute vs. chronic radiation exposure 18 Radiation burns Occur as a result of an acute localized exposure. Radiation burns can occur from a wide range of exposures and usually result from direct exposure to the primary beam. High- energy X-rays readily penetrate the outer layer of skin that contains most of the nerve endings, so you may not feel an X-ray burn until the damage has been done. Extreme cases involve skin grafts or amputation of fingers. The hands, fingers, and eyes are the parts of the body most commonly at risk. The severity of the burn will depend on the dose received, the length of the exposure, the energy of the X-rays, and the sensitivity of the individual. Burns can be caused with exposures of 300 rem, but normally do not become apparent below exposures of at least 600 rem. 19 Radiation sickness 20  Long-term Effect Long-term effects resulting from chronic exposure to ionizing radiation include carcinogenesis, life span shortening, and cataract formation. The principal delayed effect of chronic radiation exposure is an increased incidence of cancer. Long-term effects of acute exposure to radiation are often classified as leukemia and other cancers, radiation-induced life-shortening, genetic effects, and embryonic effects. Genetic defects are less likely than cancer, and not as serious, therefore, the risk of developing cancer from radiation exposure is more significant. Radiation exposure in utero can result in spontaneous abortions, congenital abnormalities, impairment of growth and mental functions, and increased incidences of leukemia. 21 22 Analytical Unit Safety Features 23 24  Regulations & Safety Practices NEVER bypass a safety device, such as interlocks and failsafe features, shutters, etc., without approval from the Radiation Safety Officer, since these devices are meant to protect you from serious harm and injury.. DO NOT operate a unit in any manner other than specified in the procedures and the conditions listed on your Radiation Use Authorization. LEARN the Standard Operating Procedures for each X-ray unit you operate. DO NOT allow anyone other than trained and certified personnel to operate the unit. ALWAYS follow the ALARA principles (Time, Distance, and Shielding) 25  DO NOT remove covers, shielding material, or tube housing or perform modifications to shutters, collimators or beam stops without verifying the x-ray tube is off and will remain off until safe conditions have been restored. The main switch, rather than interlocks, shall be used for routine shutdown. NEVER place any part of your body in the primary beam. DO NOT attempt to operate if the X-ray unit is not mechanically intact and sound. ALWAYS control access to radiation-producing equipment during use to avoid unintentional exposures. ALWAYS know the location and presence of the primary and diffracted/scattered X-ray beams 26 Health and Safety in a Radiology Facility 27 Thank You gu.edu.eg