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Solution Manual for Industrial Safety and Health Management, 7th Edition

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    CHAPTER 1 SOLUTIONS TO END-OF-CHAPTER EXERCISES 1.1. Some standards are frequently cited because these standards cover (1) areas in which industries are having difficulty complying, or (2) areas in which enforcement agencies are giving a great deal of attention, or both. 1.2. Many aspects about the standards might be useful. The text emphasizes the importance of the "why" behind the standards that do exist. 1.3. No. It is an unattainable goal. Such a strategy fails to recognize the need for discrimination among hazards to be corrected. 1.4. (1) Hazards that are physically infeasible to correct. (2) Hazards that are physically feasible, but are economically infeasible, to correct. (3) Hazards that are physically feasible and economically feasible to correct. 1.5. (1) Causes other more serious hazards to be overlooked while reacting to less serious ones. (2) Deteriorates credibility with top management. 1.6. A safety hazard is acute, causes or threatens to cause injuries, and is usually more obvious than a health hazard. A health hazard is chronic, causes or threatens to cause illness in the long run, and is usually more subtle than a safety hazard. 1.7. Some example safety hazards: unguarded belts, pulleys, gears, saws, and punch presses; fires; explosions; open platforms; defective ladders; welding near open flammable or combustible materials; overloaded or defective cranes, hoists, or slings; ungrounded electrical equipment; exposed live electrical conductors. Some example health hazards: coal dust, cotton dust, chronic loud noise, welding fumes, asbestos, vinyl chloride, lead fumes, mercury, manganese, cadmium. 1.8. Some valid examples are spray paint, coal dust, benzene, and carbon disulfide. 1.9. Some valid examples are noise, welding, and radiation. 1.10. Health hazards are usually more subtle than safety hazards; the industrial hygienist must look for "unseen" hazards. 1.11. Safety hazards may appear more grave, but there are probably many health hazard-related illnesses and deaths which are not documented. 1.12. Work training, statistics, job placement, industrial relations. 1.13. A comprehensive safety and health program involves engineering, and placement of the function within the personnel department may restrict authority too much. 1.14. This places the Safety and Health Manager in an adversarial position with enforcement officials. 1.15. CPSC concentrates on the responsibility of the manufacturers of the machines and equipment, whereas OSHA concentrates on the responsibility of the employer who places the equipment into use in the workplace. 1.16. (NSC) National Safety Council 1.17. ANSI (American National Standards Institute) Prepares voluntary standards for occupational safety and health among other types of standards. OSHA adopted many ANSI standards early on, invoking its temporary right to promulgate "national consensus standards."

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    1.18. OSHA is concerned with hazardous exposures to workers, i.e. worker safety and health. EPA is concerned with hazardous exposures to the public, particularly as these hazards affect the earth, water, and atmosphere. Many safety and health hazards inside the plant and outside are the same, or are caused by the same chemical agents or physical factors. Thus a firm's compliance with both EPA and OSHA regulations are often the responsibility of the same individual. 1.19. 1-800-CDC-INFO; the agency that responds is, obviously, NIOSH, the National Institute for Occupational Safety and Health. 1.20. Passage of The Occupational Safety and Health Act of 1970, which created the Occupational Safety and Health Administration (OSHA). 1.21. Prior to passage of the OSHA law occupational health seemed remote and not of a great deal of concern. Plant nurses were concerned with first aid and physical examinations. After OSHA, occupational disease prevention rose in importance. 1.22 The Bhopal, India disaster in which the release of methyl isocyanate gas killed 2500 civilians. This incident showed that dangerous working conditions do not just impact the workers, but everyone around a facility. 1.23 Reductions in energy consumption, for example, can lower a firm’s bottom line energy cost while decreasing its impact on the environment. 1.24 The four environmental issues addresses were global warming, green engineering, petroleum conservation, and tobacco smoke. 1.25 Green engineering is focused on the reduction of carbon fuels, which in turn directly impact global warming. 1.26 Systems Safety is considered essential in airlines, aerospace, and hospitals. These are industries in which the failure of a system can be catastrophic. 1.27 Systems Safety recognizes the benefit of such life-cycle planning and design, and the System Safety Society is one of the societies dedicated to the movement. 1.28 A chronic effect is a long-term deterioration due to prolonged exposure whereas an acute effect is a sudden reaction to a severe condition. 1.29 A safety hazard would be a sudden exposure to sound loud enough to damage hearing with one exposure. A health hazard would be continued long-term exposure to sound above the PEL which could lead to damage over a course of time. 1.30 The effects of occupational health fatalities are often delayed whereas occupational safety fatalities generally occur immediately. 1.31 The national trade associations 1.32 The primary purpose of such materials is to promote the industry products. 1.33 NIOSH 1.34 OSHA itself 1.35 ANSI and NFPA 1.36 Fear of triggering an inspection. For that reason OSHA allows questions to be posed in a hypothetical format. 1.37 The aerospace industry 1.38 The Systems Safety Society

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    CHAPTER 2 SOLUTIONS TO END-OF-CHAPTER EXERCISES 2.1. The achievement of worker safety lies principally in the hands of the workers themselves and their direct supervisors; thus it is principally a line function. Safety and health managers, however, are staff positions. 2.2. Acting as a facilitator in assisting, motivating, and advising the line function in achieving worker safety and health. 2.3. They too often are such emotional crusaders for the cause that they lose their credibility and with it their eligibility to be considered a "manager." 2.4. That safety must be achieved by line personnel facilitated by the staff function. 2.5. Go to top management to re-determine its level of commitment to safety and health. 2.6. The workers compensation system is a state, not federal system. The system is nearly 100 years old; the first workers compensation laws were introduced into state legislatures in 1909. 2.7. The ostensible purpose is to protect the worker by providing statutory compensation levels to be paid by the employer for various injuries that may be incurred by the worker. An ulterior feature is immunity from additional liability for the employer, except where "gross negligence" can be proven. 2.8. Management contends that some risk is inescapable in any line of work. Therefore, their answer to the question is no. The worker bears some of the risk in return for his/her pay for the job. 2.9. The employer or the employer's insurance carrier. 2.10. An industrial safety consultant employed by an insurance company. The consultant's objective is to keep claims low among clients of his insurance company. 2.11. A standardized recordkeeping system for industrial safety established by the National Safety Council and later superseded by OSHA's system of recordkeeping. 2.12. Differences in recordkeeping requirements for OSHA and its predecessor Z16.1 system. Other variations in conditions, such as employment levels and recession cycles impact recordkeeping. 2.13. The "lost workdays" method would not reveal some very serious accidents, especially fatalities, that do not cause a loss of a workday. 2.14. One that is work-related and requires medical treatment. 2.15. 22 x 200,000 = 44 = 14.67 150 x 40 x 50 3 2.16. The injury/illness incidence rate computation prescribed by OSHA relates to 200,000 work-hours (roughly one year for a 100-employee firm), whereas the traditional frequency rate relates to 1,000,000 work-hours (roughly one year for a 500 employee firm). Also the OSHA injury/illness incidence rate applies to all work-related injuries/illnesses which require medical treatment, whereas the traditional frequency rate related only to "lost-time" cases. 2.17. Frequency measures the numbers of cases per standard quantity of work- hours. Severity measures the total impact of cases in terms of total "lost workdays" per standard quantity of workhours. Seriousness is the ratio of severity to frequency and measures the average seriousness of all cases. All three are obsolete terms now.

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    2.18. OSHA Form 300a, the annual "Summary of Work-Related Injuries and Illnesses" must be posted on February 1 each year and remain posted until April 30. 2.19. For general records: 5 years (Chapter 5 will reveal longer retention requirements for certain records.) 2.20. Yes; they can help to discover hazards, but they can also dilute responsibility for workplace safety and health and can degenerate into spy parties. Without adequate orientation, safety and health committees can often become unreasonable. 2.21. Direct costs are the "tip of the iceberg" compared to indirect costs. 2.22. (1) Costs of wages paid for time lost by workers who were not injured. (2) Cost of damage to material or equipment. (3) Cost of wages paid for time lost by the injured worker. (4) Extra cost of overtime work necessitated by the accident. (5) Cost of wages paid supervisors for time required for activities necessitated by the accident. (6) Wage cost caused by decreased output of injured worker after return to work. (7) Cost of learning period of new worker. (8) Uninsured medical cost borne by the company. (9) Cost of time spent by higher supervision and clerical workers. (10) Miscellaneous costs such as public liability claims, rental equipment, and lost sales. 2.23. Noninjury accidents are usually caused by the same types of conditions and practices that result in injury accidents. 2.24. First-line supervisors 2.25 A six-month work period = 1000 hours. (a) General injury/illness rate = 15*200 , 000 40*1 , 000 = 3 , 000 , 000 40 , 000 = 75 (b) Traditional frequency rate = 4∗200 , 000 40∗1 , 000 = 800 , 000 40 , 000 = 20 2.26 Total Injury Incident Rate ( 3+1 ) ∗200 , 000 30∗2 , 000 = 800 , 000 60 , 000 = 13.33 LWDI 1∗200 , 000 30∗2 , 000 = 200 , 000 60 , 000 = 3.33 2.27. (a) Total incidence rate = (3+1+1+1+1) x 200,000 62 x 2000 = 11.29 (b) (According to current OSHA recordkeeping policy, count calendar days, not just workweek days, i.e. 7 days/wk, not 5 days/wk) Number-of-lost-workdays rate = (7+7+42) x 200,000 62 x 2000 = 90.3 (c) LWDI = 1 x 200,000 = 1.6 62 x 2000 (excludes illnesses and all fatalities) 2.28. The 12 first-aid cases are non-recordable. The two illnesses do not enter into the calculation of the LWDI, but the lost-time injuries would. Therefore, the LWDI would be calculated as: LWDI = 3 x 200,000 = 6.67 for the 4-month period

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    135 x (4/12) x 2000 Since 6.67 > 3.6, this would indicate that improvement is needed to meet the objective. However, if no more lost time injuries occurred for the year (an unlikely outcome): LWDI = 3 x 200,000 = 300 = 2.22 135 x 2000 135 and the objective LWDI of 3.6 would easily be met. 2.29. The classification of the 12 accident files in this case study is subject to some variation due to individual judgment. This analysis will assume the following classification: Columns on the OSHA 300 Log (a) LWDI = 3 x 200,000 = 1 = .33 900 x 2000 3 (The LWDI excludes fatalities, excludes illnesses, and includes all "lost-time" injuries, including those injuries in which the worker has "restricted work activity days," i.e. is temporarily transferred to another job, even if there are no days away from work.) Total Injury rate = (4 - 1) x 200,000 = 3 = .33 (excluding fatalities) 900 x 2000 9 Total Illness rate = (2+0+1+1) x 200,000 = 4 = .44 900 x 2000 9 Fatality rate = 1 x 200,000 = 1 = .11 900 x 2000 9 Number-of-lost-workdays rate = (70 + 38) x 200,000 900 x 2000 = 108/9 = 12 Specific hazard incidence rate (fractures) = (1 + 1) x 200,000 900 x 2000 = 2/9 = .22 Total Incidence(including fatalities = ( 8∗200 , 000 ) 900 𝑥𝑥 2000 = 8/9 = .89 (b) Comparing National Safety Council Statistics for 2000 (see Figure 2.2 of the text): File G H I J K L M1 M2 M3 M4 M5 M6 1 not recordable 2 X 14 X 3 not recordable 4 X 7 28 X 5 X X 6 X X 7 not recordable 8 X X 9 X 14 X 10 not recordable 11 X X 12 X 3 42 X Column Totals: 1 4 0 3 38 70 4 2 0 1 0 1

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    Total incidence (including fatalities) .89 << 6.8 therefore, much safer than the all industry average 2.30. Note to instructor, as is sometimes the case, despite the authors’ best efforts there was a change to the OSHA form 300 in the first printing of the Seventh Edition which has been subsequently changed in subsequent printings. The column K and colun L were reversed. Please share the updated Figure 2.9 below with your students when assigning this problem. To complete the table, add up the columns to get the following totals: (a) Injury incidence = (4 - 1) x 200,000 = 6 (excludes the fatality) 50 x 2000 (b) Illness incidence = 5 x 200,000 = 10 50 x 2000 (c) Number-of-lost-workdays rate = (67 + 16) x 200,000 50 x 2000 (counts restricted work activity days) = 83 x 200,000 = 166 100,000 (d) LWDI = 1 x 200,000 = 2 50 x 2000 File G H I J K L M1 M2 M3 M4 M5 M6 1 Empl A X 8 X 2 Empl B X 56 X 3 Empl C X 14 X 4 Empl D X X 5 Empl E X X 6 Empl F X X 7 Empl G X 2 X 8 Empl H X 3 X 9 Empl I X X Column Totals: 1 2 3 3 16 67 4 2 2 0 0 1

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    (Don't count injuries in which there were no lost workdays; also exclude fatalities) 2.31 2014 premium $120,000 2014 modifier 1.05 Unadjusted premium: $120,000/1.05 = $114,286 2016 modifier .80 2016 premium: $114,286 x .80 = $91,429 Actual savings: $120,000 - $91,429 = $28,571 % savings = ($28,571/120,000) x 100% = 23.8% 2.32. a. Lost Workday Cases: OSHA 300 cols H + I b. Cases Involving Days Away From Work & Deaths: OSHA 300 cols G + H c. Nonfatal Cases Without Lost Workdays: OSHA 300 col J d. Total Cases: OSHA 300 cols G + H + I + J (or the total of all of the M columns) e. Lost Workdays OSHA 300 cols K + L f. Days Away From Work OSHA 300 col L 2.33. Note to instructor, as is sometimes the case, despite the authors’ best efforts there was a change to the OSHA form 300 in the first printing of the Seventh Edition which has been subsequently changed in subsequent printings. The column K and colun L were reversed. Please share the updated Figure 2.9 below with your students when assigning this problem To complete the table, add up the columns to get the following totals: File G H I J K L M1 M2 M3 M4 M5 Column totals: 1 2 3 3 16 67 4 2 2 0 1

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    The following calculations are compared to National Safety Council (NSC) estimates reported in Injury Facts, 2016 edition (numbers reported are 2014): Cases Involving Days Away From Work & Deaths = (1+2) x 200,000 = 1.82 versus 1.8 (NSC) (cols G + H) 165 x 2000 Total recordable cases = (1+2+3+3) x 200,000 = 5.45 vs 6.1 (NSC) (cols G + H + I + J) 165 x 2000 Days Away From Work = 16 x 200,000 = 9.70 (cols L) 165 x 2000 (Injury Facts, 2016 edition, reports 85,000,000 days away from work for injuries incurred in the previous year (2001). The total worker force was estimated at approximately 136,500,000. Applying the formula to the national data: Days Away From Work = 65,000,000 x 200,000 = 44.43 146,307,000 x 2000 This figure is considerably higher than the 9.70 figure calculated for the data in this problem. 2.34. Social Media has brought about increased scrutiny on companies with poor safety records and is one of the hidden costs from the tip of the iceberg. 2.35. Each year the NSC publishes updates for these estimates in Injury Facts. Students might want to check the library for the latest update. The 2016 edition shows the following estimates: fatality: $1,000,000 worker injury: $29,000 2.36. A shooting in a nightclub killing 49 people. 2.37. Action on Smoking and Health lobbies for OSHA to promulgate a standard on Indoor Air Quality. OSHA has proposed a standard, but as of early 2018 it had not been promulgated as a Final Standard. 2.38. Workplace violence 2.39. The company did preemployment drug screening tests for all applicants in a three month hiring period (750 applicants). Surprisingly, half of the 750 applicants failed the test. The test was a urinalysis designed to indicate whether drugs had been used in the preceding two or three days and was conducted by a hospital laboratory service. The test results indicated that the use of marijuana was the most prevalent. ALCOA hired 130 applicants who passed the test and reported that as a group those hired were better workers than those hired prior to the drug screening program. 2.40. The firm may face discrimination charges unless it is fair and even-handed in its policies for hiring and employee termination in cases of alcohol or drug abuse. The same rules that are applied to new employees should be applied to existing employees. 2.41. No; workplace homicide is often associated with despair over downsizing or a termination notice for some other reason. There is evidence that homicide in the workplace is committed in a methodical and selective way. 2.42. Although pre-employment testing has been shown to be effective in recruiting dependable and safer employees, the program can run afoul of Title VII of the Civil Rights Act of 1964 if the testing program is discriminatory against females or racial minorities. The EEOC has published guidelines for such programs. Of particular interest is the comparative failure rates of the tests when the scores of white males is compared to those of females or racial minorities. Another consideration

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    is the Americans with Disabilities Act that protects disabled workers in much the same way as the Civil Rights Act protects females and racial minorities. 2.43. a. control of sharps b. effective system of housekeeping c. effective laundry d. effective disposal of waste e. washing, cleaning, and disinfecting exposed surfaces f. provision for storage and consumption of food in areas protected from exposure g. prohibition of application of cosmetics, lip balm, or contact lenses in exposed areas of the plant h. provision of personal protective equipment. 2.44. the eyes 2.45 The table is considered independent of inflation, as the unit of measure is “weeks” of compensation, not dollars. 2.46 To show an interest in the well-being of the employee and uncover fraudulent claims. 2.47 The number-of-lost-workdays rate counts all lost workdays (by definition one or more days for each case, whereas the LWDI is a count of incidents with one or more lost workdays. Since each lost-workday incident must have one or more days, it will always be as high or higher than the LWDI 2.48 The intent was to create a higher level of public visibility of employers with high injury rates to “nudge” them to action. This data also helped OSHA to use this “big data” to target compliance assistance and enforcement efforts. 2.49 There is a trend in states allowing employers to opt out of worker’s compensation programs. This provides savings but opens employers up to costly litigation in the event of an injury. 2.50 Most “gig” workers are not classified as employees but rather as contractors. As such, most are not covered under worker’s compensation. Uber is a leading company with a high number of gig employees. 2.51 While worker’s compensation covers 100% of the medical costs associated with a permanent injury, the payments for permanent disability do not last forever. Therefore many employers subsidize short-term and long-term disability insurance. 2.52 Many workers who re-enter the workforce do so with permanent injuries that can on average result in a 15% decrease in earning potential going forward. 2.53 The legalization of marijuana in some states while still illegal at a federal level has caused instances where legal recreational use of marijuana has resulted in failure of random drug tests and employee dismissal in some cases. 2.54 No. Any employer who can reasonably expect exposure to bloodborne pathogens for their employees is required to have a written exposure plan. 2.55 In 2008, there was a change in reporting to use hours worked instead of employment-based rates. When comparing fatality data for the last eighty years these changes in reporting method stand out from the gradual year-over-year reduction in fatalities. 2.56 Days of restricted work activity.

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    CHAPTER 3 SOLUTIONS TO END-OF-CHAPTER EXERCISES 3.1. Imminent danger, serious violations, nonserious violations, de minimus violations 3.2. De minimus 3.3. Author's opinion: Case (a) -- Cat. 1 -- De Minimus Case (b) -- Cat. 3 -- Nonserious Case (c) -- Cat. 8 -- Serious 3.4. This is a good example of a hazard that would be better controlled by training than by a hard and fast rule. Many people regularly break this rule because they have done so without injury and because the reason is not well understood by the general public. The practice can dangerously damage the connections between the cord and plug. A discontinuity in either the neutral or the grounding conductor can cause electrocution without warning by a cord and plug which appear outwardly to be safe. 3.5. This question is intended to generate a class discussion to reinforce concepts of hazard avoidance. The discussion should bring to light weaknesses in a strategy of using purely an enforcement approach alone. 3.6. Enforcement, psychological, engineering, analytical 3.7. This question may be used for class discussion. 3.8. Unsafe acts 88% Ratio = 88:10 Unsafe conditions 10% Unsafe causes 2% 100% 3.9. (1) Engineering controls (2) Administrative or work practice controls (3) Personal protective equipment 3.10. crane hoists 5:1 scaffolds 4:1 scaffold ropes 6:1 3.11. (1) General fail-safe principle--release of drill trigger (2) Fail-safe principle of redundancy-- use of both guards and worker training (3) Principle of worst case--defensive driving course 3.12. Murphy's Law is an observation of probability over a period of time. Risks of accidents are typically low but over a long period of time become significant. 3.13. FMEA (Failure Modes and Effects Analysis) is used to trace effects of individual component failures on the overall or "catastrophic" failure of equipment. 3.14. This exercise is for practice in developing fault tree diagrams. A wide variety of diagrams can be expected from students, depending upon their understanding of the fire hazards. The exercise should be evaluated upon the criteria of logical construction, not fact. 3.15.

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    P[7] = P[1 and 6] + P[2 and 5] + P[3 and 4] + P[4 and 3] +P[5 and 2] + P[6 and 1] = (1/6 • 1/6) + (1/6 • 1/6) + (1/6 • 1/6) + (1/6 • 1/6) + (1/6 • 1/6) + (1/6 • 1/6) = 6(1/36) P[7] = 1/6 3.16. Toxicology is the study of poisons and may include scientific studies in which animals are deliberately exposed to the given toxic agent in order to observe the effect. Epidemiology deals strictly with people by analyzing the causes of epidemics of illnesses among populations. 3.17. The following diagram adds a branch to the tree that considers possible faults to the double-insulation system. It also removes the branches that deal with faults in the grounding system through the third prong of the plug, because the worker would be protected by the insulated case of the tool. 3.18. Proximal causes are primary and are direct causes of accidents in the conventional sense. Distal causes are secondary, more indirect causes, but can be as important as proximal causes because the distal causes create and shape the proximal causes. Management policy should be considered a distal cause. 3.19. Personal injury is not a certainty, even though a loss incident is unavoidable. Personnel may not be exposed, or the exposure may not be injurious to personnel. Aggravating factors make the loss incident outcome more severe, and mitigating factors make the outcome less severe. 3.20. Zero. If the causes are mutually exclusive, the occurrence of Cause B precludes the occurrence of either Cause A or Cause C. 3.21. (a)

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    (b) Probability = P[11] = P[5]P[6] + P[6]P[5] = 1/6 • 1/6 + 1/6 • 1/6 = 1/36 + 1/36 = 2/36 (c) Yes; you can roll a "5" on the first die and "6" on the second or you can roll a "6" on the first die and "5" on the second but you can't do both at the same time. One "cause" precludes the occurrence of the other. 3.22. From a total plant safety perspective each of the four causes is possible and does not preclude the possibility of occurrence of any of the other three. Therefore they are not mutually exclusive. From a single accident perspective, the four causes are also not mutually exclusive, because several of the causes or factors could be present as contributors to the cause of a single accident, such as a fall. 3.23. Causes A and B are mutually exclusive because it is impossible for an adequately sized guard to be placed both too high and too low at the same time. 3.24. Tangible cost/incident 15,000 Intangible cost/incident 250,000 Total cost/incident 265,000 Expected cost/year = Cost per incident x annual incidence frequency Before installation: Expected cost/year = $265,000 x .01 = $2650 After installation: Expected cost/year = [$265,000 x .01]½ = $1325 Annual benefit = $1325 3.25. Costs Benefits Amortization $15,000 Cleaning $1,200 Maintenance 600 Resp eqpmt savings 4,000 Utilities 1,800 Short Term Illnesses 3,600 Total Costs $17,400 Long Term Illnesses 6,000 Total Benefits $14,800 The conclusion of the Cost/Benefit analysis is to not install the equipment. Primary benefit of the equipment if installed would be the savings on the cost of long term illnesses which would be prevented by the equipment. 3.26. Answers vary dependent upon analysts' judgment and experience. The following data are from a survey of 25 experienced managers.

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    lowest highest average sample size (a) 6 10 7.36 22 (b) 7 10 8.24 25 (c) 2 9 6.43 25 (d) 1 8 4.50 24 (e) 2 8 5.88 24 (f) 1 7 2.20 25 (g) 7 10 8.43 23 (h) 2 9 4.78 23 3.27. The point of irreversibility is the boundary beyond which control is lost and a loss incident will occur. Factors in the region of sphere of control are: 1. Actions 2. Limitations 3. Conditions 3.28. When the events are not mutually exclusive; when both events can happen there is a finite probability that both will happen. Therefore, the probability that both will occur is non-zero and must be subtracted from the sum of the probabilities that each event will occur. 3.29. P[C] = P[A] + P[B] - P[A]P[B] 3.30. P[C] = P[A] + P[B] - P[A]P[B] = 0.3 + 0.2 -(0.3)(0.2) = 0.5 - 0.06 = 0.44 3.31. There are many examples. A few are as follows: GENERAL FAILSAFE PRINCIPLE: OSHA standard 1910.217(b)(2) regarding the design of friction brakes that are "self-engaging," i.e., they require force or power from an external source to disengage, rather than to engage. ALSO OSHA standard 1910.217(b)(13) ".....the control system shall be constructed so that a failure within the system does not prevent the normal stopping action from being applied to the press..." AND OSHA standard 1910.179(g)(3)(viii) "Automatic cranes shall be so designed that all motions shall fail-safe if any malfunction of operation occurs." AND OSHA standard 1910.217(b)(14)(i) "Be so constructed as to automatically prevent the activation of a successive stroke if the stopping time or braking distance deteriorates to a point....." AND OSHA standard 1910.217(b)(7)(xiv) "....Reactivation of the clutch shall require restoration of normal supply and use of the tripping mechanism(s). PRINCIPLE OF REDUNDANCY: OSHA standard 1910.111(d)(9)(i) "A minimum of two compressors shall be provided either of which shall be of sufficient size to handle the loads...." ALSO OSHA standard 1910.134(d)(2)(ii) "The compressor for supplying air shall be equipped with necessary safety and standby devices." AND OSHA standard 1910.119, App C, Sect. 13: "It is important to have a backup communication network in case of power failure or one communication means fails." AND OSHA standard 1910.217, App A, Certification/Validation Requirements. Section A.2.a.(2): "Redundancy, and comparison and/or diagnostic checking, exist for the critical items..." PRINCIPLE OF WORST CASE: OSHA standard 1910.1027(n)(2)(i) "...activity involving cadmium cannot release dust or fumes in concentrations at or above the action level even under the worst-case release conditions." ALSO OSHA standard 1910.217(b)(4)(i) The pedal mechanism shall be protected to prevent unintended operation from falling or moving objects or by accidental stepping onto the pedal.

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    3.32. One concept would be safety factor. A proper safety factor would have allowed for shock loads that would be anticipated if a large number of people began to move or jump on the skywalk in unison. Another engineering concept is the failsafe Principle of Worst Case. A properly applied Worst Case Principle might have considered the possibility that large groups might move in unison. 3.33. A “deadman control” is a switching or control mechanism that causes equipment to retreat to a safe or inactive mode in the absence of a conscious action on the part of the operator. The typical control is a spring-loaded pushbutton switch as in a hand-held electric drill. Other examples of equipment, not mentioned in the book, would include floor waxing/buffing machines, hand-held saws, motorcycle throttles, and automobile accelerators. 3.34. There are many examples of the use of the concept of redundancy. One example is the provision for emergency backup power generators in the design of hospitals. Another example that applies to occupational safety and health is the provision of independent, battery-powered emergency lighting to provide illumination of means of egress from buildings in the event of power failure. 3.35. The Principle of Worst Case. 3.36. The whole concept of preventive maintenance is to service and repair or replace parts BEFORE they fail, not afterwards. FMEA can be used to examine the failure modes and provide the basis for prediction of the consequences of failure. Such analyses are valuable in justifying the replacement of components or systems before they fail. Such analysis and replacement can be of critical importance when failure of the system can result in injury to personnel. 3.37. Whether a substance is “poison” or not depends upon the degree of exposure or concentration of exposure. The field of toxicology studies the effects of poisons in various concentrations upon the body. An example of a seemingly harmless poison is acetic acid, the principal ingredient of ordinary vinegar. Ingested in small concentrations, acetic acid is a popular food additive. However, as the concentration increases, acetic acid becomes poison to humans. Irving Sax’s Dangerous Properties of Industrial Materials states that acetic acid is a moderate poison by inhalation, oral, and dermal routes. It is described as “caustic, irr(itant), can cause burns, lachrymation, and conjunctivitis. It attacks the skin easily and can cause dermatitis and ulcers. Inhalation causes irr(itation) of mu(cous) mem(branes).” 3.38. Pharmacokinetics is the study of absorption, disposition, metabolism, and elimination of chemicals in the body. It’s application to occupational safety and health is in the study of the effects of industrial chemicals upon the body, whether these chemicals are inhaled, ingested, or contacted by the skin. 3.39. Epidemiology is useful to occupational safety and health in assisting in understanding the link between observed occupational diseases and their causes. 3.40. Toxicology and epidemiology studies are typically performed by researchers whose studies may be used as the basis for the promulgation of new standards. Safety and Health Managers usually do not perform such studies themselves. They may however use the results of such studies to substantiate the psychological approach or to justify an engineering approach to solve a particular problem. 3.41. This question is intended to generate discussion or perhaps even debate. Certainly more money has been spent on dealing with asbestos hazards ($20 billion/year) as compared with expenditures in dealing with radon ($0.1 billion/year). Estimates of asbestos related fatality rates range from 0 to 8 deaths per year, and for radon, perhaps as many as 20,000 cancer deaths per year, according to Jeremy Main (ref Main). Of course, some uncertainly exists in estimating the causes of deaths which have

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    occurred. 3.42. A Poisson Process is a random event with a constant hazard of occurrence. Murphy’s Law states that “If anything can go wrong, it will. The design of a system must consider the possibility of the occurrence of some chance event that can have an adverse effect on safety and health. 3.43. The Principle of “Eliminate” 3.44. Guards protect personnel from the hazard, while barriers keep personnel out of the dangerous area. 3.45 The possibility that the warning will be ignored must be considered. 3.46 The warning label must be used sparingly so that it is not ignored. Alternate solution would be to engineer out the hazard. 3.47. The enforcement approach would be much more palatable to the public if the enforcing agency would spend more time analyzing accident histories. That way, citations would be written only for the most important violations. The psychological approach could also be strengthened a great deal by substantiating persuasive appeals with actual results of accidents. The engineering approach needs accident analysis to know where the problems are and to design a solution to deal with all of the accident mechanisms. 3.48. The enforcement approach forced motorcycle riders to wear helmets, but the psychological approach has been most effective in convincing them of the benefit and actually causing riders to use them. 3.49. Top Management support is just the beginning. If management does not show their commitment to safety and health through their priorities and actions, the safety program will be largely ineffective. 3.50. Eliminate, Substitute, Reduce or Slow Down, Guard, Barriers, Warn, Warning Labels, Filters, Exhaust Ventilation, and Human Interface. 3.51. The primary benefit is in visualizing causal relationships. 3.52 OSHA cited imminent danger which allows OSHA to seek a court injunction to cease operations or remove the hazard immediately due to the danger it presents.

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