CHAPTER 10 SAMPLE QUIZ
QUESTIONS
10.1. What material is commonly substituted for
silica sand to prevent silicosis in blasting workers?
ANS: steel
shot
ref.
p. 202
10.2. Ventilation
is considered which of the following strategies to hazard control?
a. Engineering
b.
Administrative
c.
Work practice
d.
Personal protective equipment
ref.
p. 200
10.3. For each of the following industrial
materials, suggest substitutes that are feasible for some operations and that
prevent certain hazards:
Silica (for blasting) ANS: steel shot
Lead-based paint iron
oxide pigments
Freon (as a propellant) propane
Volatile organic compounds water-based solvents
ref.
p. 201-202
10.4. What is the name given to a type of
ventilation system that can be likened to "sweeping dirt under the
rug?"
ANS: dilution
ventilation
ref.
p. 202
10.5. 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
ref.
p. 202-203
10.6. 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 or other joining process to replace welding
d. provision of respirators for
the welder
ref. 200-201
10.7. One part of a manufacturing process for metal
products involves tumbling the parts in an abrasive, and the noise in the area
of this operation is measured at 94 dBA.
An acoustics engineering firm has designed a barrier for enclosing this
operation that engineers claim will attenuate the absolute sound pressure by
50%. If the claim is correct, calculate
the new noise level in dBA generated by this operation.
ANS: The 50% reduction is equivalent to dividing
the noise in half. This is equivalent to
a 3dB decrease in noise level. Thus,
New
noise level = 94 dBA - 3 dBA = 91dBA
ref.
p. 211-212
10.8. A particularly noisy process is operated by a
single operator working at a control console.
The 8-hr TWA exposure level for this operator is 96 dBA. The company has initiated an engineering
project to alleviate the problem and has two plans:
Plan A - Move the operator's control
console from its current position 5 feet from the source of the noise to a
point 10 feet away.
Plan B - Enclose the noise source in an
enclosure that would be effective in reducing the absolute sound
pressure level of the noise by 75%.
What would be the new decibel exposure
level if
a. Plan A were carried out
ANS:
Doubling the distance reduces the noise level by a factor of 4. The dB level is thus reduced by half twice or
6 dB. New dB reading = 96 - 6 = 90 dB.
b. Plan B were carried out
ANS: Reducing
noise by 75% is reduction by a factor of 4 or a 6 dB reduction. New dB reading = 96 - 6 = 90 dB
c. Both Plan A and Plan B were
carried out
ANS: Each
plan would reduce noise by a factor of 4, resulting in a 16-fold reduction or
12 dB reduction. New dB reading = 96 -
12 = 84 dBA.
ref.
p. 211-218
10.9. 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
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.
ref.
p. 211-218
10.10. 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.
ref.
p. 211-218; also earlier chapters that emphasized the preference of engineering
and administrative controls over personal protective equipment.
10.11. 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").
2 Enclose
the noise source with a barrier that reduces the noise level by 50%.
1 Position the operator at a distance twice as
far from the source of the noise.
3 Rotate personnel so that each worker is
exposed to the noise source for only one-half shift.
4 Provide
ear protection that cuts the noise level by one half.
ref.
p. 211-218; also earlier chapters that emphasized the preference of engineering
and administrative controls over personal protective equipment.
10.12. What is a "threshold shift?"
ANS: an
indication that a worker's hearing has been damaged
ref.
p. 222
10.13. 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
ref.
p. 222
10.14. A "threshold shift" is an indication
that a worker's hearing has been damaged.
a.
true
b. false
ref.
p. 222
10.15. A "threshold shift" is a hazard of
walking and working surfaces.
a. true
b.
false
ref.
p. 222
10.16. A "threshold shift" is an
administrative control for rotating employees exposed to excessive noise.
a. true
b.
false
ref.
p. 222
10.17. A "threshold shift" is a barrier to
continued attenuation of a noise source.
a. true
b.
false
ref.
p. 222
10.18. List the elements of an effective hearing
conservation program.
ANS: audiometric
testing, noise monitoring, calibration of equipment, training, warning signs
for noisy areas, recordkeeping of audiometric tests and equipment calibration
ref.
p. 223
10.19. Hearing damage at what noise frequency is
viewed as typical of industrial exposures?
ANS: 4000 Hz
ref.
p. 223
10.20. 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
ref.
p. 223
10.21. Gamma rays and X rays typify which of the two
primary classes of radiation?
ANS: ionizing
ref.
p. 223
10.22. Radio waves and microwave radiation typify
which of the two primary classes of radiation?
ANS: non-ionizing
ref.
p. 223
10.23. The best exhaust ventilation systems are the
"push" types.
a. true
b.
false
ref.
p. 203
9.24.
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.
ANS: The
PEL is 0.1 ppm.
for
PEL:
1 ft. 3
1 in.3/hr x -----
12 in. 0.1
--------------------- =
------
X 106
0.1 X = 106/1728 =
578.7 ft3/hr
X = 5787 ft3/hr
The
for
x = 2 x 5787 = 11574 ft3/hr
ref.
p.205-206
10.25. Which is a preferred design for exhaust
ventilation systems?
(a) (b)
ANS:
b
ref.
p. 202
10.26. Which is a preferred design for exhaust
ventilation systems?
ANS:
b
ref.
p. 203
10.27. Identify the device indicated by the large
arrow. What is its purpose?
ANS: pressure
switch--to switch on alarm when filter needs service
ref.
p. 204
10.28. The device shown is a
|
a. tornado b. cyclone c. hurricane d. heat pump |
|
ref.
p. 206
10.29. The purpose of the device shown is
|
a. to remove particulates b. to
absorb toxic gases c. to act
as a heat exchanger d.
none of the above |
|
ref.
p. 206-207
10.30. The purpose of the device shown is
|
a. to remove particulates b. to
absorb toxic gases c. to act
as a heat exchanger d.
none of the above |
|
ref.
p. 206
10.31. The purpose of the device shown is
|
a. to act as a heat exchanger b. to remove particulates c. to
absorb toxic gases d.
none of the above |
|
ref.
p. 206
10.32. The purpose of the device shown is
|
a. to absorb toxic gases b. to remove particulates c. to act
as a heat exchanger d.
none of the above |
|
ref.
p. 206
10.33. The purpose of the device shown is to
|
a. reduce
ionizing radiation b. reduce
non-ionizing radiation c. charge particles d.
remove toxic gases |
|
ref.
p. 207
10.34. The purpose of the device shown is to
|
a. reduce
ionizing radiation b. reduce
non-ionizing radiation c. remove particulates d.
remove toxic gases |
|
ref.
p. 207
10.35. The device shown is identified as .
ANS:
an electrostatic precipitator
ref.
p. 207
10.36. The device shown is known as a
|
a. packed tower wet scrubber b. cyclone
precipitator c.
electrostatic precipitator d.
fabric collector |
|