CMA Post-Remediation Verification & Clearance Testing 2 — Questions and Answers
Question 1: What does a successful clearance determination in post-remediation verification indicate?
- That no mold spores are present anywhere in the building
- That mold conditions in the remediated area are similar to or below outdoor background levels (Correct answer)
- That the building's moisture problem has been permanently resolved
- That the property is guaranteed mold-free for a period of one year
Correct answer: That mold conditions in the remediated area are similar to or below outdoor background levels
Clearance means that indoor mold levels in the remediated area are comparable to outdoor background levels, not that mold is completely absent.
Question 2: If post-remediation verification sampling fails to meet clearance criteria, what must happen next?
- The mold assessor must recommend the building be condemned
- Additional remediation must be performed, followed by repeat verification sampling (Correct answer)
- The results should be averaged with the original pre-remediation samples
- A new mold assessor must be hired to conduct a second clearance test
Correct answer: Additional remediation must be performed, followed by repeat verification sampling
When clearance criteria are not met, the remediation contractor must perform additional cleaning or remediation, and the area must be re-tested before clearance can be granted.
Question 3: Which laboratory analysis method provides genus- and species-level identification of mold in air samples, rather than just spore counts?
- Spore trap analysis by direct microscopy
- Culture (viable) analysis using malt extract agar (Correct answer)
- Fiber analysis using phase contrast microscopy
- Beta-glucan ELISA testing
Correct answer: Culture (viable) analysis using malt extract agar
Viable culture analysis grows mold colonies from collected samples, allowing laboratory analysts to identify mold to the genus and species level, unlike direct microscopy spore counts.
Question 4: What is the minimum recommended volume of air typically collected per spore trap sample during clearance testing?
- 5 liters
- 25 liters
- 75 liters (Correct answer)
- 150 liters
Correct answer: 75 liters
IICRC S520 and industry protocols typically recommend collecting a minimum of 75 liters per spore trap cassette to ensure a representative air sample is obtained.
Question 5: How should HVAC systems be handled prior to collecting post-remediation clearance air samples?
- HVAC should be running at maximum speed to circulate air throughout the building
- HVAC should be shut off and sealed during sampling to prevent dilution of contaminants
- HVAC should be operating normally so conditions represent typical occupancy (Correct answer)
- HVAC filters should be removed before sampling to increase airflow
Correct answer: HVAC should be operating normally so conditions represent typical occupancy
HVAC should be operating under normal conditions during clearance sampling so that results reflect real-world occupancy conditions rather than artificially altered airflow.
Question 6: Which of the following is an example of a surface sampling method used during post-remediation verification?
- Spore trap air cassette sampling
- Tape lift or swab sample collected from a cleaned surface (Correct answer)
- Passive air sampling using an open Petri dish
- ERMI (Environmental Relative Moldiness Index) dust sampling
Correct answer: Tape lift or swab sample collected from a cleaned surface
Tape lift and swab samples are surface sampling methods used to detect residual mold on cleaned surfaces during post-remediation verification.
Question 7: Which of the following conditions would typically cause a post-remediation clearance test to be postponed?
- The outdoor temperature is below 50°F
- Visible moisture or ongoing water intrusion is still present in the remediated area (Correct answer)
- The building has been unoccupied for more than 30 days
- The laboratory turnaround time exceeds 5 business days
Correct answer: Visible moisture or ongoing water intrusion is still present in the remediated area
Active moisture or water intrusion must be resolved before clearance testing because ongoing water intrusion can support new mold growth and invalidate clearance results.
CMA Post-Remediation Verification & Clearance Testing 2
What does a successful clearance determination in post-remediation verification indicate?