CMI Post-Remediation Clearance Testing

Question 1

Post-remediation verification (PRV) clearance testing should be conducted under which site conditions to ensure valid results?

Accepted Answer

Immediately after remediation while containment barriers are still in place

Answer

After containment barriers are removed and the area has been returned to normal building conditions

Answer

During active remediation while negative air machines are running

Answer

Before final cleaning of the remediated area

Question 2

Which IICRC S520 criterion must be met for a visual inspection to pass post-remediation clearance?

Accepted Answer

No visible mold growth remains and no musty odor is present in the remediated area

Answer

Indoor spore counts must be zero

Answer

All building materials must be replaced rather than cleaned

Answer

Air sampling must show outdoor equivalence before visual inspection is attempted

Question 3

During post-remediation air sampling for clearance, what is the preferred condition regarding building HVAC and air circulation?

Accepted Answer

HVAC should be in normal operation and, if possible, the area disturbed (e.g., gentle agitation) to resuspend settled spores for a more challenging clearance standard

Answer

HVAC should be off to allow spore settling before sample collection

Answer

Windows should be open to dilute any remaining spores

Answer

Negative air machines used during remediation should remain running

Question 4

A post-remediation clearance air sample from a remediated bedroom shows a Cladosporium-dominated count slightly higher than the outdoor control. This result most likely indicates:

Accepted Answer

Normal variation; Cladosporium is a common outdoor genus and a slight indoor elevation may reflect infiltration rather than a remediation problem

Answer

Failed clearance requiring additional remediation

Answer

Stachybotrys contamination was missed during remediation

Answer

The post-remediation sampling protocol was flawed

Question 5

Post-remediation clearance testing is performed by which party to maintain objectivity under IICRC S520?

Accepted Answer

An independent third-party assessor not affiliated with the remediation company

Answer

The remediation contractor who performed the work

Answer

The property owner personally

Answer

The mold laboratory that analyzed the pre-remediation samples

Question 6

If post-remediation clearance sampling fails, the correct protocol per IICRC S520 is:

Accepted Answer

Return the area to containment, re-remediate, and re-test before issuing a clearance report

Answer

Issue a conditional clearance with noted exceptions

Answer

Raise the acceptable indoor spore count threshold to account for seasonal variation

Answer

Issue clearance if the failure was limited to one room only