INDOOR MICROBIAL SPECIALIST offers post remediation verification (PRV) inspections and testing. Often referred to as “clearance testing”, this evaluation is performed by a mold or indoor air quality (IAQ) specialist to help determine if the remediation scope-of-work (remediation protocol) was followed and if the recently cleaned environment has returned to a healthy livable space. The IIRCR (Institute of Inspection, Cleaning and Restoration Certification) defines this as Condition 1 status – a normal fungal ecology. The post-remediation verification should never be performed by the remediation contractor and is required to be a separate third-party company. However, many times this evaluation is scheduled through remediation contractors or through the homeowners themselves.


We follow the ANSI/IICRC-approved S520 Professional Guide for Mold Remediation which defines a successful remediation as reaching a Condition 1 status (normal fungal ecology). Our PRV evaluations typically follow these guidelines in determining if the remediation project is complete:


Step 1: Perform a visual inspection for remaining mold and moisture issues.


Step 2: Moisture readings are collected in various locations within the remediated areas to ensure all remaining building materials have been dried to an acceptable level.


Step 3: A thermal imagining scan of the walls, ceilings and floors is performed to check for hidden moisture issues.


Step 4: A smell test is also used to help ensure the environment is clean and free of malodors.


Step 5: If these prior steps are acceptable, we will collect air mold samples and possibly surface mold samples to ensure the environment is clean at the microscopic level.


Step 6: The samples are sent to an AIHA-approved laboratory for analysis. Typically, results are available the next day. Same day rush sample turn arounds are available for additional fees. We look for qualitatively and quantitatively similar indoor air samples as the outdoor air. Surface samples should show minimal spore levels with no toxic mold or pathogenic molds being present.


Step 7: A final report is issued outlining our findings and any recommendations. If all criteria are met, reconstruction may begin.


Industry Guidelines for Bioaerosol

Ideally, total mold spore concentrations should be lower than the outdoor control sample and absent elevated levels of “marker” molds (i.e. Aspergillus/Penicillium, Chaetomium, Cladosporium, Stachybotrys) which are specifically related to indoor moisture issues. Based on variability of outdoor mold spore concentration and distribution, caution should be used when comparing indoor to outdoor mold concentrations. When interpreting indoor air quality, the following industry guidelines were used to provide parameters to evaluating the degree of potential indoor airborne mold amplification. The guidelines are based on a “Clean” building which is free from current or historical water intrusions or elevated moisture conditions and free from elevated biological, cellulose or synthetic fibers.

• Amplification of Aspergillus/Penicillium types: if the difference between the indoor and outdoor samples is <300 Spores/m3 then indoor source is unlikely, 300-800 Spores/m3 an indoor source is possible or >800 Spores/m3 indoor source is likely.

• Amplification of Cladosporium types: if the difference between the indoor and outdoor samples is 1 to 1.4 times the outdoor concentration then an indoor source is unlikely, lower than or equal to 1.6 times the outdoor concentration then an indoor.


HOMEINSPECTORUSA, LLC (HIUSA) / INDOOR MICROBIAL SPECIALIST (IMS) uses IICRC S520 (Standard and Reference for Professional Mold Remediation) and ASTM D-7338 (Standard Guide for Assessment of Fungal Growth in houses) for reference, study, and guidelines. There are no government-issued numerical standards and published studies by mold science experts for mold interpretation. However, HIUSA/IMS use industry standards guidelines values for guidance in interpreting the bio-aerosol microbial results such as:

(I)         BIOAEROSOL: Reference: Indoor Air Quality Solutions, IAQS

                        <250 CFU/m3 Low/Normal (CFU/m3 = colony forming units/meter cubed)

                        250-1,000 CFU/m3 Moderate/Borderline

                        >1,000 CFU/m3 Active Growth/Sporulation

                        >5,000 CFU/m3 Very Active Growth/Sporulation

    CFU/m3 = Colony Forming Unit/ cubic meter

Bioaerosols are collections of airborne biological materials. Ubiquitous indoors and out, bioaerosols in suspended and cell fragments combined with byproducts of cellular metabolism. Bioaerosols are usually defined as aerosols or particulate matter of microbial, plant or animal origin that is often used synonymously with organic dust. Bioaerosols or organic dust may consist of pathogenic or non-pathogenic live or dead bacteria and fungi, viruses, high molecular weight (HMW) allergens, bacterial endotoxins, mycotoxins, peptidoglycans, β(1→3)-glucans, pollen, plant fibers, etc.



A high variability in outdoor mold spore concentrations and distribution exists on a daily to hourly basis and is dependent on local vegetation and micro-climate, the time of year, local weather patterns, and diurnal variation. As a result, caution must be used when simultaneously comparing limited data sets of inside and outside concentrations or over generalizing any set of data. Tables given below can serve as a guide to evaluating the relative degree of indoor airborne mold spore amplification. Reference: Environmental Analysis Associates (EAA / January 2011)



Any question regarding Mold Inspections, Mold Assessments and or PRVs or to schedule an appointment call 850-814-3889 or visit us at: or HOMEINSPECTORUSA, LLC


MOLD INSPECTIONS & MOLD TESTING. Two offices to serve you: The Villages & Gainesville, Florida. We service from Orange County to Alachua County Florida and everything in between. (The Villages, Leesburg, Wildwood, Ocala, Gainesville, Newberry, Micanopy, Mount Dora, Cristal River, Lady Lake, Clermont, Orlando, Eustis, Micanopy, Tavares among other cities).










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John M. Acaron, CMI, MRSA

Master Mold Inspector & Chief Mold Assessor
Home Inspections & Mold Inspections
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