Q&A Hero

Q: 28. Fires in underground gasoline tanks burn or explode with such intensity as to destroy much life and property around service stations.a. trueb. false

Q: 58. Which of the following air contaminants is recognized by ASHRAE engineers as a benchmark for general indoor air quality? a. carbon disulfide b. carbon monoxide c. hydrogen sulfide d. carbon dioxide

Q: 59. Identify some of the problems associated with stale indoor air.

Q: 60. In heating/ventilating terminology describe what is meant by a VAV air conditioning system.

Q: 61. What advantages accrue from having a VAV air conditioning system?

Q: 1. What two physical characteristics of a liquid are principally used to determine its flammability classification?

Q: 2. Which of the following physical characteristics of gasoline makes it particularly hazardous to have basements in service stations? a. vapor density b. vapor pressure c. low flash point d. low boiling point

Q: 3. What two physical characteristics of a liquid are principally used to determine its flammability classification? a. flashpoint and boiling point b. flashpoint and firepoint c. boiling point and firepoint d. volatility and boiling point

Q: 4. What principal physical characteristic of gasoline makes it particularly hazardous to have basements in service stations?

Q: 5. What is the principal criterion for determining whether wiring for flammable paint spray areas must be Class I Division 1 or Division 2?

Q: 6. The proper wiring selection for areas twenty feet or more away from flammable paint spray booths is: a. Class I, Division 1 b. Class I, Division 2 c. Class II, Division 1 d. conventional wiring

Q: 52. Describe some engineering solutions to the problem of toxic air contaminants arising from surface coatings during the welding process. Indicate a priority to rank the preference for the solutions to the problem.

Q: 7. Which of the following is best classified as a Class B explosive? a. nitroglycerin b. dynamite c. black powder d. propellant

Q: 53. An operator is exposed to the following sources of noise:Source A: 81 dBASource B: 83 dBASource C: 85 dBAPerform calculations to determine the approximate overall noise exposure to the worker. Show your work.

Q: 8. Which of the following is best classified as a Class A explosive? a. black powder b. propellant c. photographic flash powder d. explosive rivets

Q: 54. An operator working an 8-hour shift is exposed to 85 dbA the first half of the shift and 92 dbA the second half. Calculate the noise dose. Does the total dose exposure exceed the OSHA PEL? Does it exceed the AL?

Q: 9. Which of the following is best classified as a Class C explosive? a. black powder b. propellant c. photographic flash powder d. explosive rivets

Q: 55. Explain why barrels are often found under filter baghouses.

Q: 10. Ethylene dichloride, a soil fumigant, has the following properties:a. LEL 6.2%b. UEL 15.9%c. FLASHPOINT 56 oFd. BOILING PT 83.5 oCe. PEL (TWA) 50 ppmf. PEL (C) 100 ppmg. STEL 200 PPM Duration: 5 minutes in any 3 hoursA manufacturing process liberates 3 cubic feet of ethylene dichloride per hour.a. Calculate the minimum general exhaust ventilation required to keep the atmosphere around this process safe from fire and explosion. State any necessary assumptions.b. Calculate the minimum general exhaust ventilation required to prevent a health hazard for this process.

Q: 56. What organization is represented by the abbreviation ASHRAE?

Q: 11. The definition of "liquid" by NFPA as far as flammable liquids are concerned has little to do with vapor pressure.a. trueb. false

Q: 57. What particular air contaminant is gaining recognition as a general benchmark for indoor air quality?

Q: 12. Flashpoint is the temperature at which a fire on top of the liquid is sustained.a. trueb. false

Q: 41. Which (pressure vs. time) waveform represents a high pitched loud sound?abcD

Q: 43. Assume the worker in the diagram is equidistant from each machine and compute noise exposure.

Q: 44. The diagram illustrates a. absolute noise pressure and pitch b. noise enclosure effectiveness c. octave band analysis d. none of the above

Q: 45. The diagram illustrates a. absolute noise pressure and pitch b. noise enclosure effectiveness c. octave band analysis d. none of the above

Q: 46. An air sample bag is needed at the PEL for carbon disulfide (20 ppm). The smallest quantity of carbon disulfide available for this experiment is 5 ml. Calculate the minimum capacity air sample bag necessary for this experiment. Show your calculations.

Q: 47. You are requested to design a general exhaust ventilation system to deal with a process that leaks hexachloroethane into the plant air at the rate of one cubic inch per hour. How much flow in cubic feet per hour is needed to keep the hexachloroethane vapors within OSHA limits (PEL and AL)? The PEL is 1 ppm.

Q: 31. The purpose of the device shown isa. to act as a heat exchanger b. to remove particulates c. to absorb toxic gases d. none of the above

Q: 48. Noise Source A has a sound power level of 99 dB, and noise Source B has a sound power level of 82 decibels. Compute the ratio of absolute sound power between Source A and Source B.NOTE TO INSTRUCTOR: This examination question goes beyond the scope of the text. It is a technical question intended for students who have an engineering or science background. Supporting lecture notes for instructors who desire to teach this technical extension of Chapter 10 topics are available from the author.

Q: 32. The purpose of the device shown isa. to absorb toxic gases b. to remove particulates c. to act as a heat exchanger d. none of the above

Q: 49. A certain drying process produces 5 cubic feet of methanol vapors per hour. The PEL for methanol is 200 ppm. If general exhaust ventilation is used, calculate how much flow in cubic feet per hour is needed to keep the methanol vapors within OSHA limits. Show your calculations.

Q: 33. The purpose of the device shown is toa. reduce ionizing radiation b. reduce non-ionizing radiation c. charge particles d. remove toxic gases

Q: 50. Explain why it seems so difficult to reduce noise decibel levels even by a "small" amount, such as 5 or 6 decibels.ANS. In terms of absolute sound pressure level, a reduction in decibel level of 5 or 6 decibels is NOT really a "small" amount. Due to the logarithmic ratio scale, a reduction of noise level by only three decibels corresponds to a reduction in the absolute sound pressure level by a factor of two (that's cutting the sound pressure level IN HALF). A reduction of 6 dB corresponds to reducing the absolute sound pressure level by 75% (or a factor of four).A more detailed answer follows:

Q: 34. The purpose of the device shown is toa. reduce ionizing radiation b. reduce non-ionizing radiation c. remove particulates d. remove toxic gases

Q: 51. Explain, in terms easily understood by workers and managers, the following physical characteristics of occupational noise:a. the physical characteristic of noise that gives rise to the sensation of pitch.b. the physical characteristic of noise that gives rise to the sensation of loudness.c. how noise is affected by the distance to the source (in what way and at what proportional rate).d. how doubling the absolute sound pressure affects decibel level (in what way and by how much).

Q: 35. The device shown is identified as .

Q: 36. The device shown is known as aa. packed tower wet scrubber b. cyclone precipitator c. electrostatic precipitator d. fabric collector

Q: 37. What is the specific purpose of the electric motor indicated by the large arrow?

Q: 38. Which (pressure vs. time) waveform represents a low pitched soft sound? a b c D

Q: 39. Which (pressure vs. time) waveform represents a high pitched soft sound? a b c D

Q: 40. Which (pressure vs. time) waveform represents a low pitched loud sound? a b c D

Q: 25. Which is a preferred design for exhaust ventilation systems? (a) (b)

Q: 10. Which of the following would be least effective in dealing with a work-related noise exposure problem? a. Enclose the noise source with a barrier that reduces the noise level by 50%. b. Position the operator at a distance twice as far from the source of the noise. c. Rotate personnel so that each worker is exposed to the noise source for only one-half shift. d. Provide ear protection that cuts the noise level by one half.

Q: 26. Which is a preferred design for exhaust ventilation systems?

Q: 11. From the perspective used by the federal enforcement agency, rank the following solutions to a worker noise exposure problem (from most effective,"1", to least effective,"4").

Q: 27. Identify the device indicated by the large arrow. What is its purpose?

Q: 12. What is a "threshold shift?"

Q: 28. The device shown is a a. tornado b. cyclone c. hurricane d. heat pump

Q: 13. A "threshold shift" is a. a hazard of walking and working surfaces b. an administrative control for rotating employees exposed to excessive noise c. a barrier to continued attenuation of a noise source d. an indication that a worker's hearing has been damaged

Q: 29. The purpose of the device shown isa. to remove particulates b. to absorb toxic gases c. to act as a heat exchanger d. none of the above

Q: 14. A "threshold shift" is an indication that a worker's hearing has been damaged.a. trueb. false

Q: 30. The purpose of the device shown isa. to remove particulates b. to absorb toxic gases c. to act as a heat exchanger d. none of the above

Q: 15. A "threshold shift" is a hazard of walking and working surfaces.a. trueb. false

Q: 16. A "threshold shift" is an administrative control for rotating employees exposed to excessive noise.a. trueb. false

Q: 17. A "threshold shift" is a barrier to continued attenuation of a noise source.a. trueb. false

Q: 18. List the elements of an effective hearing conservation program.

Q: 19. Hearing damage at what noise frequency is viewed as typical of industrial exposures?

Q: 20. Which of the following noise frequencies is viewed as typical of industrial exposures? a. 1000 Hz b. 4000 Hz c. 10000 Hz d. 20000 Hz

Q: 21. Gamma rays and X rays typify which of the two primary classes of radiation?

Q: 22. Radio waves and microwave radiation typify which of the two primary classes of radiation?

Q: 23. The best exhaust ventilation systems are the "push" types.a. trueb. false

Q: You are requested to design a general exhaust ventilation system to deal with a process that leaks bromine into the plant air at the rate of one cubic inch per hour. Calculate how much flow in cubic feet per hour is needed to keep the bromine vapors within OSHA limits (PEL and AL). Show your calculations.

Q: 33. Appendix A.1 lists "Copper fumes" as having a TWA limit of .1 mg/m3. The corresponding PEL in the ppm column is blank. Explain why no ppm PEL is available for copper fumes.

Q: 9. Which of the following would be most effective in dealing with a work-related noise exposure problem? a. Enclose the noise source with a barrier that reduces the noise level 50%. b. Position the operator at a distance twice as far from the source of the noise. c. Rotate personnel so that each worker is exposed to the noise source for only one-half shift. d. Provide ear protection that cuts the noise level by one half.

Q: 34. Explain the standards completion project.

Q: 35. What is a teratogen?

Q: 36. An irritant whose effects upon the lung are minimal at first but whose irritant mechanical action shows up much later is called a. scarring agent b. teratogen c. mutagen d. systemic poison

Q: 37. In which of the following types of workers would you be most likely to find the nose septum completely destroyed? a. cement worker b. plating worker c. steel worker d. asbestos worker

Q: 38. Ammonia is primarily which of the following types of air contaminants? a. irritant b. systemic poison c. depressant d. asphyxiant

Q: 39. At first, OSHA emphasized safety more than health.a. trueb. false

Q: 40. Early methods for testing contamination of the atmosphere, using a canary or a mouse, were used for testing which kind of exposure, acute or chronic?

Q: 1. What material is commonly substituted for silica sand to prevent silicosis in blasting workers?

Q: 2. Ventilation is considered which of the following strategies to hazard control? a. Engineering b. Administrative c. Work practice d. Personal protective equipment

Q: 3. For each of the following industrial materials, suggest substitutes that are feasible for some operations and that prevent certain hazards: Silica (for blasting)

Q: 4. What is the name given to a type of ventilation system that can be likened to "sweeping dirt under the rug?"

Q: 5. Which of the following types of ventilation most resembles sweeping dirt under the rug? a. dilution ventilation b. exhaust ventilation c. push-pull ventilation d. makeup air ventilation e. ordinary heating and air conditioning systems

Q: 6. Which of the following solutions is preferred for the problem of toxic air contaminants arising from the surface coatings of materials during the welding process? a. ventilation b. removal of the coatings prior to welding c. substitution of crimping/joining process to replace welding d. provision of respirators for the welder

Q: 31. The proportion of health specialists in OSHA has increased since the early 1970s.a. trueb. false