NIOSH 582: SAMPLING AND EVALUATING AIRBORNE
ASBESTOS DUST
Comprehensive Examination Questions & Answers — V2.0
Advanced-Level | Verified Answers with Detailed Rationales | Latest
Exam Update
TABLE OF CONTENTS
Section Topic Questions
I Regulatory Framework & Exposure Limits 1–15
II Asbestos Mineralogy & Fiber Characteristics 16–30
III Sampling Equipment, Calibration & Physics 31–50
IV Advanced Sampling Protocols & Strategies 51–70
V Microscopy Setup, Alignment & Optics 71–90
Counting Rules, Fiber Identification &
VI 91–110
Ambiguities
Quality Assurance, Quality Control &
VII 111–130
Statistics
Advanced Calculations, Conversions &
VIII 131–145
Reporting
IX Complex Scenario-Based & Problem-Solving 146–150
,SECTION I: REGULATORY FRAMEWORK & EXPOSURE
LIMITS
• 1. Which of the following correctly pairs the OSHA asbestos standard with its respective
industry sector?
A) 29 CFR 1910.1001 — Construction
B) 29 CFR 1926.1101 — General Industry
•• C) 29 CFR 1915.1001 — Shipyard Employment ••
D) 40 CFR Part 763 — Mining
Rationale: 29 CFR 1915.1001 is the OSHA asbestos standard for shipyard employment. 29 CFR
1910.1001 covers general industry, while 29 CFR 1926.1101 covers construction. 40 CFR Part
763 addresses EPA AHERA requirements for schools, not mining. MSHA standards for mining
are found in 30 CFR Part 56 and 57.
• 2. What is the relationship between the OSHA Action Level and the Permissible Exposure
Limit (PEL) for asbestos?
A) The Action Level is twice the PEL
•• B) The Action Level is half the PEL ••
C) The Action Level is equal to the PEL
D) The Action Level is one-tenth the PEL
Rationale: The OSHA Action Level for asbestos is 0.05 f/cc as an 8-hour TWA, which is exactly
half of the PEL (0.1 f/cc). The Action Level triggers requirements for exposure monitoring,
medical surveillance, and employee training, even when exposures are below the PEL.
• 3. Which of the following statements about the OSHA Excursion Limit (EL) is CORRECT?
A) The EL is 0.5 f/cc measured over a 15-minute sampling period
B) The EL is 1.0 f/cc measured over a 15-minute sampling period
•• C) The EL is 1.0 f/cc measured over a 30-minute sampling period ••
D) The EL is 0.1 f/cc measured over a 30-minute sampling period
,Rationale: The OSHA Excursion Limit is 1.0 f/cc averaged over a 30-minute sampling period.
This limit was promulgated as an amendment on September 14, 1988. The flow rate range for
EL samples is 1.6–2.5 L/min.
• 4. NIOSH Method 7400 is the standard analytical method for asbestos fiber counting.
Which of the following is a CORRECT statement about this method?
A) It can differentiate between asbestos and non-asbestos fibers using specialized staining
B) It requires Transmission Electron Microscopy (TEM) for accurate counting
•• C) It uses Phase Contrast Microscopy (PCM) and cannot differentiate asbestos from other
fiber types ••
D) It is only applicable to personal breathing zone samples, not area samples
Rationale: NIOSH 7400 is the standard PCM method for sampling and evaluating airborne
asbestos fibers. A fundamental limitation of PCM is its inability to differentiate asbestos from
non-asbestiform fibers—it counts all fibers meeting the size and aspect ratio criteria regardless
of mineral type.
• 5. A workplace air sample analyzed by NIOSH 7400 yields a concentration of 0.08 f/cc as an
8-hour TWA. Which of the following is TRUE regarding regulatory compliance?
A) The sample is below the Action Level and requires no further action
•• B) The sample is above the Action Level but below the PEL, triggering certain compliance
requirements ••
C) The sample exceeds the PEL and requires immediate corrective action
D) The sample is invalid because it falls below the limit of detection
Rationale: At 0.08 f/cc, the sample exceeds the Action Level (0.05 f/cc) but remains below the
PEL (0.1 f/cc). This triggers requirements including periodic exposure monitoring, medical
surveillance, and employee training, but does not require the more stringent engineering
controls or respiratory protection mandated for PEL exceedances.
• 6. Which of the following regulatory standards applies to asbestos in schools under the
Asbestos Hazard Emergency Response Act (AHERA)?
A) 29 CFR 1910.1001
, B) 29 CFR 1926.1101
•• C) 40 CFR Part 763 ••
D) 30 CFR Part 56
Rationale: 40 CFR Part 763 contains the EPA's AHERA regulations, which mandate inspection,
reinspection every three years, and development of management plans for asbestos-containing
materials in schools.
• 7. What is the estimated limit of detection (LOD) for NIOSH Method 7400, and what does it
represent?
A) 5 fibers/mm²; the minimum number of fibers that can be visually distinguished
•• B) 7 fibers/mm²; the minimum fiber density that can be reliably detected above
background at a 99% confidence level ••
C) 10 fibers/mm²; the threshold for reporting a sample as positive
D) 100 fibers/mm²; the lower limit of the optimal counting range
Rationale: The estimated LOD for NIOSH 7400 is 7 fibers/mm². This represents the minimum
fiber density that can be reliably detected above background at a 99% confidence level. Counts
below this threshold have greater uncertainty and may not be distinguishable from
background contamination.
• 8. A laboratory reports a sample as "uncountable" or "probably biased." Which of the
following conditions would MOST LIKELY trigger this designation?
A) The sample has fewer than 100 fibers counted in 100 fields
•• B) The fiber density exceeds 1300 fibers/mm² or more than 50% of the filter area is
covered with particulate ••
C) The sample was collected at a flow rate outside the 0.5–2.5 L/min range
D) The sample volume was less than 400 liters
Rationale: Fiber counts above 1300 fibers/mm² and samples with more than 50% of filter area
covered with particulate shall be reported as "uncountable" or "probably biased". Such samples
cannot yield reliable quantitative results due to excessive fiber density or particulate
interference.
ASBESTOS DUST
Comprehensive Examination Questions & Answers — V2.0
Advanced-Level | Verified Answers with Detailed Rationales | Latest
Exam Update
TABLE OF CONTENTS
Section Topic Questions
I Regulatory Framework & Exposure Limits 1–15
II Asbestos Mineralogy & Fiber Characteristics 16–30
III Sampling Equipment, Calibration & Physics 31–50
IV Advanced Sampling Protocols & Strategies 51–70
V Microscopy Setup, Alignment & Optics 71–90
Counting Rules, Fiber Identification &
VI 91–110
Ambiguities
Quality Assurance, Quality Control &
VII 111–130
Statistics
Advanced Calculations, Conversions &
VIII 131–145
Reporting
IX Complex Scenario-Based & Problem-Solving 146–150
,SECTION I: REGULATORY FRAMEWORK & EXPOSURE
LIMITS
• 1. Which of the following correctly pairs the OSHA asbestos standard with its respective
industry sector?
A) 29 CFR 1910.1001 — Construction
B) 29 CFR 1926.1101 — General Industry
•• C) 29 CFR 1915.1001 — Shipyard Employment ••
D) 40 CFR Part 763 — Mining
Rationale: 29 CFR 1915.1001 is the OSHA asbestos standard for shipyard employment. 29 CFR
1910.1001 covers general industry, while 29 CFR 1926.1101 covers construction. 40 CFR Part
763 addresses EPA AHERA requirements for schools, not mining. MSHA standards for mining
are found in 30 CFR Part 56 and 57.
• 2. What is the relationship between the OSHA Action Level and the Permissible Exposure
Limit (PEL) for asbestos?
A) The Action Level is twice the PEL
•• B) The Action Level is half the PEL ••
C) The Action Level is equal to the PEL
D) The Action Level is one-tenth the PEL
Rationale: The OSHA Action Level for asbestos is 0.05 f/cc as an 8-hour TWA, which is exactly
half of the PEL (0.1 f/cc). The Action Level triggers requirements for exposure monitoring,
medical surveillance, and employee training, even when exposures are below the PEL.
• 3. Which of the following statements about the OSHA Excursion Limit (EL) is CORRECT?
A) The EL is 0.5 f/cc measured over a 15-minute sampling period
B) The EL is 1.0 f/cc measured over a 15-minute sampling period
•• C) The EL is 1.0 f/cc measured over a 30-minute sampling period ••
D) The EL is 0.1 f/cc measured over a 30-minute sampling period
,Rationale: The OSHA Excursion Limit is 1.0 f/cc averaged over a 30-minute sampling period.
This limit was promulgated as an amendment on September 14, 1988. The flow rate range for
EL samples is 1.6–2.5 L/min.
• 4. NIOSH Method 7400 is the standard analytical method for asbestos fiber counting.
Which of the following is a CORRECT statement about this method?
A) It can differentiate between asbestos and non-asbestos fibers using specialized staining
B) It requires Transmission Electron Microscopy (TEM) for accurate counting
•• C) It uses Phase Contrast Microscopy (PCM) and cannot differentiate asbestos from other
fiber types ••
D) It is only applicable to personal breathing zone samples, not area samples
Rationale: NIOSH 7400 is the standard PCM method for sampling and evaluating airborne
asbestos fibers. A fundamental limitation of PCM is its inability to differentiate asbestos from
non-asbestiform fibers—it counts all fibers meeting the size and aspect ratio criteria regardless
of mineral type.
• 5. A workplace air sample analyzed by NIOSH 7400 yields a concentration of 0.08 f/cc as an
8-hour TWA. Which of the following is TRUE regarding regulatory compliance?
A) The sample is below the Action Level and requires no further action
•• B) The sample is above the Action Level but below the PEL, triggering certain compliance
requirements ••
C) The sample exceeds the PEL and requires immediate corrective action
D) The sample is invalid because it falls below the limit of detection
Rationale: At 0.08 f/cc, the sample exceeds the Action Level (0.05 f/cc) but remains below the
PEL (0.1 f/cc). This triggers requirements including periodic exposure monitoring, medical
surveillance, and employee training, but does not require the more stringent engineering
controls or respiratory protection mandated for PEL exceedances.
• 6. Which of the following regulatory standards applies to asbestos in schools under the
Asbestos Hazard Emergency Response Act (AHERA)?
A) 29 CFR 1910.1001
, B) 29 CFR 1926.1101
•• C) 40 CFR Part 763 ••
D) 30 CFR Part 56
Rationale: 40 CFR Part 763 contains the EPA's AHERA regulations, which mandate inspection,
reinspection every three years, and development of management plans for asbestos-containing
materials in schools.
• 7. What is the estimated limit of detection (LOD) for NIOSH Method 7400, and what does it
represent?
A) 5 fibers/mm²; the minimum number of fibers that can be visually distinguished
•• B) 7 fibers/mm²; the minimum fiber density that can be reliably detected above
background at a 99% confidence level ••
C) 10 fibers/mm²; the threshold for reporting a sample as positive
D) 100 fibers/mm²; the lower limit of the optimal counting range
Rationale: The estimated LOD for NIOSH 7400 is 7 fibers/mm². This represents the minimum
fiber density that can be reliably detected above background at a 99% confidence level. Counts
below this threshold have greater uncertainty and may not be distinguishable from
background contamination.
• 8. A laboratory reports a sample as "uncountable" or "probably biased." Which of the
following conditions would MOST LIKELY trigger this designation?
A) The sample has fewer than 100 fibers counted in 100 fields
•• B) The fiber density exceeds 1300 fibers/mm² or more than 50% of the filter area is
covered with particulate ••
C) The sample was collected at a flow rate outside the 0.5–2.5 L/min range
D) The sample volume was less than 400 liters
Rationale: Fiber counts above 1300 fibers/mm² and samples with more than 50% of filter area
covered with particulate shall be reported as "uncountable" or "probably biased". Such samples
cannot yield reliable quantitative results due to excessive fiber density or particulate
interference.
