3- Unit review exercises

Question 1

Which statement describes grab sampling?
a. Sample collected over a period of time.
b. Samples taken must be analyzed by a certified laboratory.
c. Instantaneous sample to provide a quick estimate of air quality.
d. Samples taken to demonstrate compliance with health standards.

Answer 1

c. Instantaneous sample to provide a quick estimate of air quality.

Question 2

49. (420) Integrated sampling is also referred to as
    a. compliance screening.
    b. instantaneous sample.
    c. direct reading or screening compliance.
    d. indirect reading or continuous monitoring.

Answer 2

d. indirect reading or continuous monitoring.

Question 3

50. (421) Which type of instrument is best suited for determining a life threatening oxygen deficient
    environment?
    a. Indoor air quality monitors.
    b. Carbon monoxide monitors.
    c. Oxygen monitors.
    d. Multi gas meters.

Answer 3

c. Oxygen monitors.

Question 4

51. (421) What type of device is capable of separating mixtures of chemicals into individual
    components?
    a. Multi-gas monitors.
    b. Colorimetric tubes.
    c. Gas Chromatographs.
    d. Indoor air quality monitors.

Answer 4

c. Gas Chromatographs.

Question 5

52. (421) What is a common device used for collecting air samples for laboratory analysis?
    a. Hazardous Air Pollutants on Site (HAPSITE).
    b. Active sampling pumps.
    c. Mercury vapor monitor.
    d. Carbon monoxide monitor.

Answer 5

b. Active sampling pumps.

Question 6

Which is an example of an adsorption device?
a. Filters.
b. Cyclone.
c. Sorbent tube.
d. Fritted bubbler.

Answer 6

c. Sorbent tube.

Question 7

54. (422) What are the most commonly used devices for particulate sampling?
    a. Filters.
    b. Sorbent tubes.
    c. Fritted bubblers.
    d. Passive dosimeters.

Answer 7

a. Filters.

Question 8

Which device allows separation of particles by size?
a. Fritted bubbler.
b. Sorbent tube.
c. Cyclone.
d. Filters.

Answer 8

c. Cyclone.

Question 9

56. (423) What is an air sample that is collected for 11 hours of a 12-hour shift?
    a. Full-period single.
    b. Single-batch process.
    c. Full-period consecutive.
    d. Partial-period consecutive.

Answer 9

a. Full-period single.

Question 10

57. (423) Although the true limits are not to be exceeded, which can be a single sample or a series of
    consecutive samples totaling 15 minutes?
    a. Grab.
    b. Area.
    c. Random.
    d. Ceiling.

Answer 10

d. Ceiling.

Question 11

When sampling for vapors, minimum and maximum flow rates are used with a solid sorbent
tube to ensure
a. the tube is correctly placed.
b. flexibility in your sampling strategy.
c. the sample is collected without damaging the media.
d. the contaminant will be in contact with collection media long enough to be captured.

Answer 11

d. the contaminant will be in contact with collection media long enough to be captured.

Question 12

The recommended flow rate of an example chemical is 0.5 to 1.0 liters per minute (lpm). If
you wanted to calculate the minimum amount of time you can sample and still meet the limit of
detection, what flow rate would you use?
a. 0.25 lpm.
b. 0.5 lpm.
c. 1.0 lpm.
d. 1.5 lpm.

Answer 12

c. 1.0 lpm.

Question 13

When determining the collection volume for an air sample, you would opt to collect less
volume of air when
a. media collection efficiency is low.
b. media collection efficiency is high.
c. concentrations are expected to be low.
d. concentrations are expected to be high.

Answer 13

d. concentrations are expected to be high.

Question 14

What item must be field checked but cannot be calibrated?
a. Toxic gas monitors.
b. Personal sampling pumps.
c. Hand-held sampling pump.
d. Combustible gas monitors.

Answer 14

c. Hand-held sampling pump.

Question 15

When should gas and vapor meters be field calibrated?
a. Monthly.
b. After use.
c. Before use.
d. Before and after use.

Answer 15

d. Before and after use.

Question 16

When performing a detector tube system check, how many minutes should you wait after
squeezing the pump to look for the end of stroke indicator?
a. 5.
b. 10.
c. 15.
d. 40.

Answer 16

15

Question 17

Why is a single “blank” run sufficient as an operational check for the HAPSITE®?
a. The HAPSITE® contains internal gas standards.
b. The survey method completes calibration.
c. Additional peaks and a high background is indicated.
d. Standby mode sufficiently calibrates the instrument.

Answer 17

a. The HAPSITE® contains internal gas standards.

Question 18

When setting up the calibration train, you must assemble the sample pump, tubing, primary
or secondary standard calibrator and
a. rotometer.
b. pump holder.
c. sample media.
d. buret holder.

Answer 18

c. sample media.

Question 19

When performing post sampling calibration, if there is a change in the flow rate use the
lowest flow rate for calculating the volume collected because
a. it is the most conservative.
b. it exploits the device’s capabilities.
c. this accounts for atmospheric changes.
d. it makes DOEHRS data entry the most efficient.

Answer 19

a. it is the most conservative.

Question 20

To ensure pumps will not be tampered with, who should you discuss the importance of air
sampling with before placing your pumps in a fixed location?
a. Workers.
b. Base safety.
c. Squadron commander.
d. Workplace supervisor.

Answer 20

d. Workplace supervisor.

Question 21

Blank samples are prepared and shipped along with air samples to
a. measure the effects of temperature and pressure changes during shipping.
b. measure the effects of temperature and pressure changes during the sampling process.
c. determine if any contamination occurred after calibrating the sampling pumps and before
sampling began.
d. determine if any contamination occurred from the time the media was opened until the time it
reached the laboratory.

Answer 21

d. determine if any contamination occurred from the time the media was opened until the time it
reached the laboratory.

Question 22

How do you prepare a blank?
a. Keep an unopened tube with the samples.
b. Sample another worker away from the process.
c. Open and immediately seal the media in the work area.
d. Leave an opened tube in an area throughout sampling.

Answer 22

c. Open and immediately seal the media in the work area.

Question 23

When collecting breathing zone air samples the flow rate changed since you began
sampling. As a worst-case measure, which flow rate observed should be used to determine
volume collected?
a. First.
b. Lowest.
c. Highest.
d. Average.

Answer 23

b. Lowest.

Question 24

The scheduled work week has changed to 8 hours per day/6 days a week. Which reduction
factor formula should be used to determine the equivalent occupational exposure limit-time
weighted average (OEL-TWA)?
a. Hourly.
b. Daily.
c. Weekly.
d. Monthly.

Answer 24

. Weekly.

Question 25

After determining the equivalent occupational exposure limit (OEL), you have to compare it to the sampling results based on the full exposure period. Using the Brief and Scala model, if the work shift was 10 hours a day, you divide the actual time you sampled by how much? a. 8. b. 10. c. 24. d. 40.

Answer 25

10

Question 26

In most cases when you receive air sampling results back from the laboratory you will need to calculate the time weighted average (TWA) and compare the results to the applicable occupational exposure limit (OEL). The laboratory results are in milligrams per cubic meter (mg/m3); your OEL results are in part per million. In order to compare results, what must you convert your air sampling results to? a. M3 b. mg. c. ppm. d. mg/m3

Answer 26

c. ppm.

Question 27

After the results from mass/volume concentration air sampling are received you find the results are reported in grams. Before you can use the formula to determine mass/volume concentration, you will have to convert the results reported in grams into what measure? a. milliliters (ml). b. milligrams (mg). c. milligrams squares (m2). d. No conversion required.

Answer 27

b. milligrams (mg).

Question 28

Field volume refers to a. volume drawn through the sampling media. b. volume under field conditions. c. field atmospheric conditions. d. volume at 32 degrees Celsius (C).

Answer 28

b. volume under field conditions.

Question 29

If you are sampling at a site that is separated from your base, it is prudent to calibrate the air-sampling pump a. at your home base. b. every 24 hours. c. repeatedly. d. at the site.

Answer 29

d. at the site

Question 30

If you sample for 7 hours of a 10-hour shift and can document that the worker is never exposed during the remaining three hours, you should calculate the time weighted average using which value? a. 3 hours. b. 7 hours. c. 8 hours. d. 10 hours.

Answer 30

d. 10 hours

Question 31

If you sample for 6 hours of an 8 hour shift and the worker stays in the area after sampling, you should calculate the time weighted average using which value? a. 4 hours. b. 6 hours. c. 7 hours. d. 8 hours.

Answer 31

b. 6 hours

Question 32

What must you calculate from the sampling and analytical error and your air sampling results to determine whether the time weighted average could be above the occupational exposure limit? a. Accuracy. b. Coefficient of variation. c. Upper confidence limit (UCL). d. Lower confidence limit (LCL).

Answer 32

c. Upper confidence limit (UCL)

Question 33

Which would it be prudent to do if the time-weighted average (TWA) is already above the occupational exposure limit (OEL)? a. Resample and recalculate the TWA. b. Compute the compliance factor. c. Calculate the lower confidence limit (LCL). d. Re-calculate the upper confidence limit (UCL).

Answer 33

c. Calculate the lower confidence limit (LCL)

Question 34

You should use a compliance factor to consider the effects of exposure to xylene, methyl chloride, and perchloroethylene because the chemicals a. react to each other. b. attack the same organ in the same way. c. produce irritation at high concentrations. d. cause the same illness in different organs.

Answer 34

b. attack the same organ in the same way.

Question 35

If air sampling showed that a worker is exposed to concentrations of 35 ppm xylene (occupational exposure limit (OEL), 100 ppm), 20 ppm methyl chloride (OEL, 50 ppm), and 25 ppm perchloroethylene (OEL, 50 ppm) and these chemicals have a similar toxicological effect what would be their total atmospheric concentration? a. 45 ppm. b. 80 ppm. c. 200 ppm. d. 280 ppm.

Answer 35

b. 80 ppm

Question 36

When considering additive effects of chemicals, the occupational exposure limit (OEL) is exceeded if the compliance factor is which of the following? a. Less than one. b. Greater than one. c. Less than or equal to one. d. Greater than or equal to one.

Answer 36

b. Greater than one

Question 37

Using the provided concentrations 20 parts per million (ppm) xylene (occupational exposure limit (OEL), 100 ppm), 20 ppm methyl chloride (OEL, 50 ppm), and 20 ppm perchloroethylene (OEL, 50 ppm), what is the unity for the compliance factor? a. 0.4. b. 0.8. c. 1.0. d. 1.2.

Answer 37

c. 1.0.