Certified Industrial Hygienist (CIH) Pre-Examinationhse.niordc.ir/uploads\86_121_CIH Examination answers.pdf · 3. Which test is most ... above Question 3: Certified Industrial Hygienist

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In the name of God

Certified Industrial Hygienist (CIH) Pre-Examination

National Iranian Oil Refining &

Distribution Company

First Name: ………………………………. Second Name: …………………………..

Identification Number: ………………….. Company: …………………….…………

Position: ………………………………… Work Experience: …………………. years

Degree: ………………………………… Field/Major: ………………………………………

Health, Safety and Environmental Department Date: 23/04/1389

Certified Industrial Hygienist (CIH) Pre-Examination National Iranian Oil Refining and Distribution Company Date: 23/04/1389

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1. A production process produces sensible heat at the rate of 82,000 BTU/hour. What is the

required air flow to keep the temperature rise to 5 C or less? A. 419 cfm B. 8436 cfm C. 15185 cfm D. 16872 cfm Question 1: Here is the equation to determine the air flow:

)(08.1)/(

ThrBYTUbleHeatTotalSensicfm

∆= Where ∆T= change in temperature in °F

1. Solve for ∆T. Remember that there is a 9 °F rise for each 5 °C in temperature.

F9C5F95 °=°°

°=∆ CT

2. Solve for cfm

8436)9(08.1

82000==cfm

The correct solution is B.

2. Which type of radiation is associated with health effects of exposure to radon gas? A. Alpha B. Beta C. Gamma D. Ultra-violet Question 2: The most significant threat from radon gas is exposure to alpha radiation. The correct solution is A.

3. Which test is most likely to be used by a physician when diagnosing an asbestos related disease? A. MRI B. CBC C. FEV1 D. None of the above Question 3:


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An MRI is Magnetic Resonance Imaging. CBC is Complete Blood Count. FEV1 (Forced Expiratory Volume) is the amount of air forced out of the lung in 1 second. Asbestos related diseases are typically lung diseases. FEV1 is more likely to be used than an MRI in diagnosing an asbestos related disease especially early on in the diagnosis. The correct solution is C.

4. What is the recommended face velocity for a laboratory fume hood? A. 20 – 60 fpm B. 80 – 120 fpm C. 120 – 160 fpm D. It depends on the contaminant and the generation rate in the hood. Question 4: The recommended face velocity for a laboratory fume hood is 80 to 120 fpm. The correct solution is B.

5. A new employee, ready to start work in a high noise area, has an audiogram that shows significant hearing loss prior to starting work. The employee has stated that he frequently listens to a personal music player with earphones set at a loud setting. How would this hearing loss be classified?

A. Presbycusis B. Sociacusis C. Nosoacusis D. Occupational hearing loss Question 5: Presbycusis is hearing loss caused by the aging process. Sociacusis is hearing loss associated with the noises of everyday life. Occupational hearing loss is caused by work related noise exposure. Nosoacusis is hearing loss attributable to other causes. The correct solution is B.

6. Select the best location to check for a source of Legionnaire’s Disease? A. Surface sampling of mold B. Airborne sampling of bacteria C. Water sample of cooling tower reservoir D. Airborne sampling of particulate matter Question 6: Legionnaire’s Disease is caused by a bacterium that grows well in warm, stagnant water. The correct solution is C.


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7. Which type of air cleaning device is most appropriate for the wood shop of a furniture factory?

A. Absorber B. Electrostatic Precipitator C. Cyclone D. Venturi Scrubber Question 7: A wood shop is likely to create large particles of wood dust. The absorber is used for chemical vapors. The electrostatic precipitator and the venturi scrubber are efficient at removing very small particles. The correct solution is C.

8. Given the following data, determine the 95% upper confidence limit of the mean.

22 32 22 99 28 A. 11.9 B. 16.4 C. 64.8 D. 69.3 Question 8: Step 1: Determine the mean.

Step 2: Determine the standard deviation.

Step 3: Determine the 95% upper confidence limit of the mean. 95% upper confidence limit The correct solution is C.

9. Which worker is likely to be exposed to high concentrations of crystalline silica? A. Worker replacing refractory in a steel mill B. Trash collector C. Chemical operator in an oil refinery D. Worker preparing glass to be recycled Question 9:


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Refractory is the ceramic lining of steel buckets and containers used in a steel mill. The process involves chipping out the ceramic material. There is potential for high exposure to crystalline silica. The correct solution is A.

10. Which respirator is most likely to have the highest assigned protection factor? A. Half-face APR B. Full-face tight fitting PAPR C. Full-face APR D. Loose fitting PAPR Question 10: Assigned protection factors are set in OSHA’s respiratory protection standard 29 CFR 1910.134. The correct solution is B.

11. What is the major mechanism of toxicity for carbon monoxide? A. Carbon monoxide blocks oxygen bonding to hemoglobin. B. Carbon monoxide stimulates P450 enzymes. C. Carbon monoxide stimulates the immune system causing sensitization. D. None of the above is correct. Question 11: Carbon monoxide in blood forms carboxyhemoglobin blocking the ability of blood to carry oxygen. The correct solution is A.

12. A 1 ft3 compressed gas cylinder containing carbon dioxide gas has a pressure of 500 psig at normal temperature. A leak in the cylinder lowers the gauge reading to 250 psi. What is the volume of the leaked carbon dioxide gas at normal pressure and temperature?

A. 0.05 ft3

B. 0.5 ft3

C. 17 ft3

D. The answer cannot be determined from the information given. Question 12: Use the ideal gas law to calculate the change in volume.

Where


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The temperature does not change in this problem. The amount of the gas that leaked

The initial volume of the amount of gas that leaked

The correct solution is C.

13. An industrial hygienist sampled the air at 2 liters/minute for 450 minutes. The lab counted an average of 5.6 fibers/field on the cassette. Blank cassettes had an average of 0.3 fibers/field.What was the asbestos concentration in the air?

A. 0.29 f/cm3

B. 0.31 f/cm3 C. 0.58 f/cm3 D. 2.9 f/cm3

Question 13:

The fiber field density is given by whereA

NB

Nf

Ef

Bf

−

=

=fN

f field fiber count per field

=BN

B blank fiber count per field

=fA the area of a field (0.00785 mm2)

67500785.0

3.06.5=

−=E fiber/mm2

The asbestos concentration is given by s

casb V

EAC1000

= where

cA is the area of the cassette= 385 mm2

sV is the air volume sampled (liters)= literslpm 900min4502 =× The correct solution is A.

14. Which of the following directly affects the hood efficiency in a local exhaust ventilation system?


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A. Airflow B. Velocity C. Hood shape D. All of the above Question 14: The geometry (or shape) of the hood determines the efficiency of air entering the system. The correct solution is C.

15. Select the correct definition of relative risk for an epidemiological study. Relative risk is …. A. the ratio of disease incidence in an exposed group compared to the disease incidence in an unexposed group B. the increased risk of developing a disease based on genetic family (relatives) relationships. C. the increased risk of developing a disease based on proximal association with diseased persons. D. the probability that the study conclusions are the result of random error. Question 15: Relative risk is the ratio of disease incidence in an exposed group compared to the disease incidence in an unexposed group. Here is an example. Suppose that a worker group exposed to chemical X has a cancer incidence rate of 22 per 1,000 people and the cancer incidence rate for a worker group not exposed to chemical X is 3 per 1,000.

The relative risk of exposure to chemical X is 3.710003100022

=

The correct solution is A.

16. Select the best method to analyze an air sample of aromatic hydrocarbons? A. Ion chromatography B. X-ray fluorescence C. Atomic Absorption D. Gas chromatography Question 16: Ion chromatography is useful for analyzing contaminants with strong ions including acids and bases. X-ray fluorescence is and atomic absorption is useful for metals. The correct solution is D.

17. What is the approximate wavelength of visible light? A. 200 – 400 nm B. 400 – 700 nm C. 700 – 1400 nm D. 1400 nm – 2800 nm


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Question 17: Ultra-violet light (UV) has a wavelength of 200 nm to 400 nm. Visible light has a wavelength of approximately 400 nm to 700 nm. Infrared light has a wavelength of 700 nm to 1400 nm. The correct solution is B.

18. Methanol has a molecular weight of 32 and a specific gravity of 0.792. What is the vapor volume generated by evaporation at a room temperature of 70 degrees F at sea level (760 mm Hg)?

A. 14.7 cu ft/gal B. 27.4 cu ft/gal C. 17.4 cu ft/gal D. 79.3 cu ft/gal Question 18: First you must calculate pounds/gal, then convert that to lbs/mole. Since 8.3 lbs of water is equal to one gallon, 8.3 x .792= 6.58 lbs methanol per gallon. The next step is to use the ideal gas law to obtain the volume of methanol at room temperature and 760 mmHg.

PV = nRT P = 1 atm V = unknown n = 6.58lbs x (454g/lb) x (1mole/32g MeOH)=93.4 moles T = 273+20 R = 0.082 l atm/o mole V = ((93.4)(0.082)(293))/1 = 2244 liters of methanol

Since 1 cu ft = 28.3 liters, 2244/28.3 = 79.3 cu ft/ gal

The correct solution is D.

19. The function of a catalyst is to: A. Change the ratio of products B. Alter the ratio of products and the rate of reaction C. Change the rate of reactions D. Modify the products forthcoming from the reaction Question 19: The function of a catalyst is to change the rate of a reaction. Usually the catalyst greatly increase the reaction rate but undergoes no permanent change itself. The correct solution is C.


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20. The ventilation system for an inside flammable liquid storage room must provide for a complete change of air at least:

A. 1 time per minute B. 6 times per hour C. 10 times per hour D. 25 times per hour Question 20: In 29 CFR 1910.106, OSHA requires 6 times room changes of air per hour for an inside flammable liquid storage room. The correct solution is B.

21. Placing importance on individual differences, a work station or system should be designed to fit _______% of the population:

A. 50 B. 90 C. 95 D. 99.7 Question 21: When an appeal is aimed at the average, it misses much of the population because each person differs from the other, in spite of common characteristics. A better approach is the use of percentiles. When designing the system, instead of setting the standards to fit the average, design it to fit all but the upper 5% and the lower 5%. Then the system will fit 90% of the population. The correct solution is B.

22. Sound is a pressure phenomenon. If the sound pressure were doubled, how much would the sound level in decibels increase?

A. Approximately six B. Double C. Be halved D. Increase exponentially Question 22: Number of dB = 20 log P(1)/P(2); with P(1) double the P(2) value 20(log 2/1) = 20(log2 - log1) = 20(.30103-0) = 6 Where P(1) is pressure1; P(2) is pressure2 The correct solution is A.

23. Calculate the dose equivalent (Leq) for the following noise exposure:

90 dBA for 2 hours 100 dBA for 1 hour


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105 dBA for 0.5 hours 115 dBA for 0.5 hour 85 dBA for 4 hours

A. 105 dBA B. 100 dBA C. 100.5 dBA D. 99 dBA Question 23: Dose= 2 hrs/8hrs + 1 hr/2 hrs + 0.5 hr/1 hr + 0.5 hrs/0.25 hr + 4 hrs/16 hrs= 3.5 or 350%

The denominator is the allowable exposure time to the numerator noise level. Then subsitute the 3.5 into the equation below.

(Leq)=90 + 16.61(log D)=90 + 16.61 (log 3.5)=99 dBA


24. Which particle(s) is considered to be radioactive by itself? A. Alpha B. Beta C. Neutron D. Proton Question 24: When removed from the nucleus of its atom, the neutron decays with a half-life of about 12 min. into a beta particle and a proton. This fact is used for shielding of nuclear reactors. The correct solution is C.

25. Antimony is used extensively as a constituent of printer's type. It is also commonly used in the semiconductor industry as a dopant. The symptoms of antimony poisoning are similar to:

A. Cadmium poisoning B. Arsenic poisoning C. Copper poisoning D. Manganese poisoning Question 25: The symptoms of antimony poisoning resemble those of arsenic with the possible exception that vomiting may be more severe. The trivalent salts of antimony are much more toxic than the pentavalent derivatives. The correct solution is B.

26. A room 50 x 20 x 10 feet contains 100 ppm of Carbon tetrachloride. How much time is required to lower the concentration to 25 ppm if a blower generating 300 cfm is used to clear the room?

A. 46.0 min


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B. 11.1 min C. 7.5 min D. 54.0 min Question 26: t=log10(C/Co)(-2.303)(P/Q)

Where P= Room volume Co=Beginning concentration C=Ending concentration Q=Flow.

Substituting we get: t=log10(25/100)(-2.303)(10000 ft3/300 cfm) t=46 min

The correct solution is A.

27. Which device might be used as an air cleaning device for removing chlorine gas from an airstream?

A. Absorber B. ESP C. Cyclone D. Baghouse Question 27: The ESP, cyclone and baghouse are used for removing particulates from an airstream. The absorber is the only option listed that will remove gases and vapors. The correct solution is A.

28. Select the statement that is not true regarding gasses. A. A gas fills the volume of its container. B. Gas pressure is directly proportional to the gas volume. C. Gas pressure is inversely proportional to the gas temperature. D. The pressure of a gas at 100 C is twice the pressure of a gas at 50 C in the same container. Question 28: Gasses follow the ideal gas law PV = nRT where T is the absolute temperature of a gas. Absolute temperature is given in either Kelvin (K) or Rankine (R). Kelvin = degrees Celsius + 273.15 Rankine = degrees Fahrenheit + 460 The pressure of a gas at 100 C is not twice the pressure of a gas at 50 C.


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29. What is the physical pressure created by an 89 dB noise? A. 0.00079 Pa B. 0.56 Pa C. 16 Pa D. 16,000 Pa Question 29: Use the following equation to solve this problem:

⎟⎟⎠

⎞⎜⎜⎝

⎛=

0

20PPLogSPL Where

SPL = sound pressure level (dB) P = physical pressure P0 = reference pressure (20 µPa)

⎟⎠⎞

⎜⎝⎛

×= − Pa

PLog 610202089

⎟⎠⎞

⎜⎝⎛

×= − Pa

PLog 6102045.4

⎟⎠⎞

⎜⎝⎛

×= − Pa

P6

45.4

102010

( )( ) PaPaP 56.0101020 45.46 =×= − The correct solution is B.

30. Chemical A and chemical B are in a mixture of a process in a work place. These chemicals are dispositionally antagonistic with each other. The industrial hygienist for the work place uses a standard additive model of mixtures to determine the TLV for the mixture. Which statement below is correct regarding the mixture TLV?

A. The mixture TLV from the model is likely to be accurate. B. The mixture TLV from the model is likely to be over protective. C. The mixture TLV from the model is likely to be insufficient. D. There is not enough information to choose A, B or C. Question 30: The standard additive model of TLV mixtures assumes that the chemical effects are additive in the body. However, these chemicals are antagonistic and will work against each other. The ultimate result is that the health effect will be lower with the exposure to both chemicals than either one individually. The correct solution is B.


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31. A manufacturing facility uses an enclosing hood around a small printing press. The press is used to imprint information directly on the product. Emissions from the press include vapors from solvents and inks. There are no noticeable aerosols being generated. What is the recommended transport velocity for the air inside duct attached to the hood?

A. 1,000 fpm B. 3,000 fpm C. 5,000 fpm D. 7,000 fpm Question 31: Recommended transport velocity for a gas or vapor is 1,000 to 2,000 fpm according to the ACGIH Ventilation Manual. Higher velocities will significantly increase operating costs for the ventilation system. The correct solution is A.

32. Which of the following biohazards is a bacteria? A. Toxoplasmosis B. Legionella C. Hepatitis D. Common Cold Question 32: Toxoplasmosis is caused by a parasitic protozoon. Legionella is caused by a bacterium. Hepatitis is viral. The common cold is viral. The correct solution is B.

33. Which type of welding process typically produces the greatest amount of noise? A. Shielded metal arc welding B. Gas tungsten arc welding C. Submerged welding D. Plasma welding Question 33: The noise level in the operator position of a plasma arc welder may be in the range of 110 to 120 dBA. The correct solution is D.

34. Which of these substances is most closely linked to skin cancer? A. Cadmium B. Lead C. Hexavalent chromium D. Arsenic


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Question 34: Cadmium exposures have been linked with prostate and lung cancers as well as pulmonary edema. Lead exposures have been linked nervous system health effects and blood disorders. Hexavalent chromium exposures have been linked to lung cancer, kidney and liver damage, eye injuries and skin ulcerations. Arsenic exposures have been linked to liver, bladder, kidney, lung, lymphatic and skin cancers. They are also linked to peripheral neuropathy, dermatitis, nasal septum ulcers and skin hyperpigmentation. The correct solution is D.

35. Which of the following respirators is required to have an annual fit-test? A. Filtering facepiece B. Loose fitting PAPR C. Tight fitting PAPR D. Both A and C Question 35: All tight fitting respirators must be fit-tested annually. The correct solution is D.

36. Which type of ionizing radiation does not have mass? A. Alpha B. Beta C. Neutrons D. Gamma Question 36: Alpha particles consist of 2 protons and 2 neutrons. Beta particles are electrons. Gamma radiation is electromagnetic energy. The correct solution is D.

37. Studies indicate that people engaged in these activities have acquired the greatest number of infections:

A. Construction B. Healthcare C. Research D. Agriculture Question 37: The correct solution is C.


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38. Which of the following best describes carpal tunnel syndrome? A. Elbow and shoulder swelling and inflammation B. Inflammation of the channel in the wrist C. Raynaud's syndrome of the hand and wrist D. White finger Question 38: The correct solution is A.

39. What is the normal line of sight at rest? A. 10 degrees upward B. 10 degrees downward C. 15 degrees upward D. 15 degrees downward Question 39: The correct solution is B.

40. The most common of the work related musculoskeletal disorders, and in economic terms, the most costly is:

A. Back pain B. Carpal Tunnel Syndrome C. Trigger finger D. Tennis elbow Question 40: The correct solution is A.

41. This agency publishes the Work Practices Guide for Manual Lifting: A. OSHA B. ANSI C. NIOSH D. ASSE Question 41: The correct solution is C.

42. Carpal tunnel syndrome include all of the following symptoms, except: A. Numbness in the little finger


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B. Pain in the wrist upon exertion C. Pain in the second and third finger D. Inflammation and swelling of the wrist Question 42: The correct solution is B.

43. Industrial hygiene includes the development of corrective measures in order to control health hazards by reducing or eliminating:

A. injuries B. exposures C. hazards D. risks Question 43: The correct solution is C.

44. Industrial hygiene exposure control measures may include all of the following, except: A. substitution of toxics B. ventilation C. changing work procedures D. rule enforcement Question 44: The correct solution is D.

45. These hazards arise from excessive airborne concentrations of mists, vapors, gases, or solids in the form of dusts or mists:

A. chemical hazards B. biological hazards C. ergonomic hazards D. physical hazards Question 45: The correct solution is A.

46. These hazards include improperly designed tools, work areas, or work procedures: A. chemical hazards B. biological hazards


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C. ergonomic hazards D. physical hazards Question 46: The correct solution is C.

47. The effects of noise on humans include all of the following, except: A. psychological effects B. interference with communications C. physiological effects D. physical effects Question 47: The correct solution is D.

48. Under OSHA law employers must protect employees from all of the following, except: A. near miss B. injury C. illness D. death Question 48: The correct solution is A.

49. The purpose of the NIOSH is to: A. conduct research and educate employers on best practices in safety and health B. conduct research and make recommendations that improve OSHA standards C. conduct research and make recommendations that prevent work-related injury and illness D. conduct research and publish warnings regarding unsafe work practices Question 49: The correct solution is C.

50. The fishbone diagram is used to: A. identify root causes B. establish a sequence of events C. determine flow over time D. establish the vital few The correct solution is A.


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Explanation Questions:

51. Describe the fundamentals of heat exchange between the human body and the environment for:

Convection: Convection is the transfer of heat by movement of air over the surface of a body. Conduction: Conduction is another method of heat transfer, but it is of little significance in air environments. Conduction is also important when the body contacts an object of extreme temperature. Radiation: The body exchanges heat with its surroundings through radiation. Thermal radiation is highest for wavelengths in the infrared region. Radiation involves the geometric relationship between the surfaces of two bodies. Evaporation: Humans have the capability to sweat as a means for cooling the body.

52. What is the full name of following abbreviation?

Abbreviation Full Name

AB Accredited Body ACGIH American Conference of Industrial Hygienists AICHE American Institute of Chemical Engineers AIHA American Industrial Hygiene Association API American Petroleum Institute ASSE American Society Safety Engineer ASTM American Society for Testing and Materials BLS Bureau of Labor Statistics CB Certificate Body CFR Code of Federal Regulation CGA Compressed Gas Association CSA Canadian Standard Association EPA Environmental Protection Agency ILO International Labour Organization IMO International Marine Organization ISO International Standard Organization MSDS Material Safety Data Sheet NFPA National Fire Protection Association NSC National Safety Council OSHA Occupational Safety and Health Administration UL Underwriters Laboratories, Inc. WHO World Health Organization

53. Write the full name and explain them:

LD50 : Lethal Dose 50% means that 50% of a test population died of a particular dose. TWA: (Time-Weighted Average) A worker's average exposure to an air contaminant, physical stress, or bio-organism over the work period or shift. Also referred to as the time weighted average concentration.


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STEL: (Short Term Exposure Time). A 15 minute time weighted average exposure to a substance which should not exceeded at any time during a workday even if the 8 hours exposure is within TLV-TWA. TLV: The Threshold Limit Value of a chemical substance is a level to which it is believed a worker can be exposed day after day for a working lifetime without adverse health effects. LD10: (Lethal Dose 10%) A calculated dose of a substance which is expected to cause the death of 10% of an entire defined experimental animal population.

54. Explain the following expressions: Face Shield: A face shield is a device used to protect wearer's entire face (or part of it) from impact hazard such as flying objects and road debris, chemical splashes (in industry), or potentially infectious fluid. Eyewash: Eyewash is the apparatus used to physically wash the eyes in the case that they may be contaminated by foreign materials or substances. Safety Net: A large net for catching one that falls or jumps. Lanyard: A short rope which used for fastening something or securing rigging.

55. Name different types of Ionising Radiation Alpha, Beta, Gamma, , Neutron, X-ray

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Certified Industrial Hygienist (CIH) Pre-Examinationhse.niordc.ir/uploads\86_121_CIH Examination answers.pdf · 3. Which test is most ... above Question 3: Certified Industrial Hygienist