Volume 3: Unit 3 Flashcards
Which statement describes grab sampling?
Instantaneous sample to provide a quick estimate of air quality
Integrated sampling is also referred to as _____
indirect reading or continuous monitoring
Which type of instrument is best suited for determining a life-threatening oxygen deficient environment?
Oxygen monitors
What type of device is capable of separating mixtures of chemicals into individual components?
Gas Chromatographs
Which is an example of an adsorption device?
A) Filters
B) Cyclones
C) Sorbent Tube
D) Fritted Bubbler
C) Sorbent tube
Although the true limits are not to be exceeded, which can be a single sample or a series of consecutive samples totaling 15 minutes?
Ceiling
What are the most commonly used devices for particulate sampling?
Filters
Which device allows separation of particles by size?
Cyclone
When sampling for vapors, minimum and maximum flow rates are used with a solid sorbent tube to ensure ________
The contaminant will be in contact with collection media long enough to be captured
When determining the collection volume for an air sample, you would opt to collect less volume of air when _____
Concentrations are expected to be high
What item must be field checked but cannot be calibrated?
Hand-held sampling pump
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?
1.0 lpm
When should gas and vapor meters be field calibrated?
Before and after use
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?
15 minutes
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 ______
It is the most conservative
When setting up the calibration train, you must assemble the sample pump, tubing, primary or secondary standard calibrator and ______
Sample media
Why is a single “blank” run sufficient as an operational check for the HAPSITE®?
The HAPSITE® contains internal gas standards
Blank samples are prepared and shipped along with air samples to _____
Determine if any contamination occurred from the time the media was opened until the time it reached the laboratory
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?
Workplace supervisor
How do you prepare a blank?
Open and immediately seal the media in the work area
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?
Lowest
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)?
Weekly
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?
milligrams (mg)
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?
10
Field volume refers to _____
volume under field conditions
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?
ppm
If you are sampling at a site that is separated from your base, it is prudent to calibrate the air-sampling pump ________
at the site
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?
10 hours
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?
6 hours
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?
c. Upper confidence limit (UCL)
Which would it be prudent to do if the time-weighted average (TWA) is already above the occupational exposure limit (OEL)?
Calculate the lower confidence limit (LCL)
You should use a compliance factor to consider the effects of exposure to xylene, methyl chloride, and perchloroethylene because the chemicals ______
Attack the same organ in the same way
When considering additive effects of chemicals, the occupational exposure limit (OEL) is exceeded if the compliance factor is which of the following?
Greater than one
If air sampling showed that a worker is exposed to concentrations of 35 ppm xylene (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?
80 ppm
Using the provided concentrations 20 parts per million (ppm) xylenes (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?
1.0
What is a common device used for collecting air samples for laboratory analysis?
Active sampling pumps
What is an air sample that is collected for 11 hours of a 12-hour shift
Full period single
