Mold Clearance Timing - When to Schedule the Mold Clearance Inspection

Mold clearance inspection procedures: timing of mold testing after a mold cleanup job; - when to inspect and test a building after mold cleanup
Wait time & other recommendations for mold clearance testing after a mold remediation project
Mold Clearance Procedure Outline: When & How to Inspect and Test after Mold Cleanup
What building areas should be tested?
How does a building "pass" a mold clearance inspection & test?
MOLD CLEARANCE INSPECTIONS - separate article
- CLEARANCE PROCEDURES - separate article
- MOLD CLEARANCE TIMING
- ACCEPTABLE MOLD LEVEL - separate article
- MOLD CLEANUP, VISUAL CHARACTERISTICS - separate article
- MOLD CLEARANCE TEST, SUCCESSFUL - separate article
- MOLD LEVELS IN BUILDINGS - separate article
- MOLD CLEARANCE: FOLLOWUP STEPS - separate article
MOLD PREVENTION GUIDE - separate article
Questions & Answers about testing & inspecting a building after a mold remediation project
References

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Mold clearance test details: when to schedule an inspection and testing after a mold cleanup project. Here we explain and describe in more detail the post remediation mold clearance procedures and testing that should be used after a mold remediation or mold cleanup project.

MOLD CLEARANCE TEST TIMING: When to Inspect & Test a Building After a Mold Cleanup / Remediation Project

This article is part of our ACTION GUIDE which provides an easy to understand step-by-step guide for dealing with toxic or allergenic indoor mold and other indoor contaminants: what to do about mold "mildew," moisture, in your house or office, building-related illness, involving your physician, treatment, sick building investigators, reduction of irritants, and special products to help clean buildings and air.

As we noted at MOLD CLEARANCE INSPECTIONS and CLEARANCE PROCEDURES, the inspection and testing of a building to confirm that a mold cleanup project (mold remediation) has been adequately performed should not be scheduled until

After the mold remediation company has completed all demolition, moldy debris removal, and moldy surface cleanup that are to be performed
After the conditions that caused the mold problem have been corrected (lest we waste the cost of cleanup by having a new mold problem)
After any building air scrubbers or exhaust systems are off for 24 hours or more: equipment used during the remediation project should have been turned off for 24-hours or longer (to allow time for dust settlement indoors). See Sill Air Conditions, below.
Before the mold remediation project containment barriers have been removed. This permits the inspector to evaluate the workmanship of the containment system, its completeness, evidence of failure or collapse. More, this procedure also means that areas of the building outside the remediation work space remain protected against cross-contamination by moldy dust until the inspection and lab work have confirmed that the cleanup was successful. Finally, should the inspection or lab work indicate that more cleaning is needed, this process saves the cost of having to re-install containment as well as the possible cost of having to perform extra cleaning outside of the containment area.
Before the remediation area is re-occupied by people at extra risk from building air quality concerns such as asthmatics, elderly, immune, infants, etc.
While the building remains in still-air conditions: windows and doors to outside are closed.
Building mechanical systems:
1. If weather conditions permit, the building heating or cooling system should be left off to avoid the risk of re-contaminating those systems before the successful clearance has been confirmed.
2. An exception may be necessary in cold climates during freezing weather, or in hot humid climates to control humidity.
3. HVAC systems serving the remediation area, their air handlers and duct work should be included in clearance inspection and testing, and if clearance includes (as we recommend) checking out of the cleanup area for cross contamination, all building HVAC systems should be included in that procedure.

The Role of Still Air Conditions in Post Remediation Mold Clearance Testing

Don't Perform Post Mold Remediation Testing Too Soon

24-hours of still air conditions is the minimum time we want to allow for settlement of airborne dust and debris in a buildings before conducting an air or surface dust screening test for mold contamination after a mold cleanup project. Longer dust settlement time is better.

Our photo (left) shows a very clean building basement that has been sealed as well. The air scrubber machine remained in the building but as we asked, it had been turned off prior to our onsite inspection. The containment barriers are not visible in this photo and would need to be verified if only part of the building was being cleaned.

At remediation jobs for which we have been the clearance inspector, we require no less than 24 hours of still air time. The containment is left in place, the air scrubbers are simply turned off. That allows the clearance inspector to evaluate the quality of dust containment that was set up, and if, as sometimes happens, more cleaning is needed, the containment does not have to be put up a second time, thus saving some money.

And allowing settlement time means that if there was poor cleaning, and the air is still contaminated, we can often find that evidence in settled dust - more reliably than may be found by dashing in and simply grabbing a quick "air sample" (We use both methods).

We have rarely encountered a mold remediation company who objected to our clearance protocol - after all, the more confident everyone can be in the quality of the clearance inspection the more all parties are protected, including the mold remediator. In a few cases in which the remediator wanted us to test while their machines were running (and we have done so) once we explain the issues to the client, that has been the end of any debate on time periods.

Don't Perform Post Mold Remediation Testing Too Late

However, to protect the mold remediation company from being blamed for contamination that may have occurred due to subsequent building leaks or events, or from cross-contamination of the mold remediation work area by mold from other building areas that was excluded from the project (not an exclusion that we recommend), we suggest that

The post remediation clearance inspection and test be performed before mold containment barriers have been removed.
The post remediation clearance inspection and test should be performed in not more than five days after the completion of the cleanup project. 24-48 hours is recommended.
The post remediation inspection should include a report of visible or known conditions at the building that present a risk of future leaks, moisture problems, and mold contamination

Post-Mold-Remedation Procedures that are Specifically NOT Recommended Include

Violating any of the conditions described above at MOLD CLEARANCE TIMING above.

Taking Down the Containment Barriers Too Soon

Our photo (below left) was part of compelling evidence that the mold remediation crew at this New York City apartment cleanup job had been inexperienced to say the least. The plastic containment barrier had been removed when we arrived to inspect the building. But we found a number of troubling conditions including

The plastic containment barrier had been "hung" from the fire sprinkler heads using duct tape strips. Good grief. What if during the project someone pulls that down and sets off the sprinkler system, creating a new building flood? What if there is a fire during the project and the sprinkler heads have been tampered-with or blocked? And why was the ceiling cavity left open to receive dust during demolition, transporting it over other areas of the apartment?

Mold containment failure (C) Daniel Friedman

Our second photo (above right) shows that the plastic used to seal around an air scrubber exit port had collapsed - probably not a serious failure at this job.

We understand that it can be costly for a mold remediation company to leave equipment idle at a property while waiting for the post-cleanup inspection, testing, lab work, report, and client approval. But that concern should not extend to early removal of the containment system as well.

The temptation to rip down the building containment system before the inspection and clearance test comes from several thoughts in the remediator's viewpoint:

It seems efficient to take down and dispose of containment while the full remediation work crew is still on site - avoiding having to send laborers back to the jobsite after the clearance test
The remediation company may be confident (perhaps sometimes overconfident) that their work has been successful
The remediation company may not want the clearance inspector to evaluate their containment methods, especially where amateur workmanship have been involved.

By premature takedown of the dust containment system risks costs we introduced above.

It prevents the inspector from supporting the remediation company's workmanship on the containment system by direct observation
Early containment removal this procedure also means that areas of the building outside the remediation work space remain protected against cross-contamination by moldy dust until the inspection and lab work have confirmed that the cleanup was successful.
Finally, should the inspection or lab work indicate that more cleaning is needed, this process saves the cost of having to re-install containment as well as the possible cost of having to perform extra cleaning outside of the containment area.

Leaving the Air Scrubbers Running

Remediators - some - would like you to test while their air machine is running, having the fantasy that even if they didn't remove all the mold they should-have, the scrubber will hide that fact ... until later, after everyone has gone and the remaining mold propagates again.

Sometimes this approach - leaving a scrubber on - allows the remediator to shoot themselves in the foot, especially when the company foolishly did not vent the air machine to the outdoors. In that case if there is problem dust and debris remaining, the machine is simply stirring it up further. You cannot remove an indoor air particle problem by vacuuming the air. As long as the particle source remains there is, in a practical effect, an infinite particle source.

Leaving Building Windows & Doors Open

A second approach that some remediators like is to have the clearance performed while the building is being aggressively ventilated with outdoor air. This too can obscure an in-building remaining mold or particle source problem in or out of the remediation area, and in some conditions can also bring in excessive levels of outdoor pollen or mold. Or moisture, or even rain at an unattended building.

While ventilating a building with outdoor air may work in some cases to help clean up a building interior, it is impossible to distinguish reliably between outdoor conditions and indoor building conditions if the building windows and doors are open 24-hours before or during the clearance inspection.

U.S. EPA Guidance for Mold Clearance Inspection After a Mold Cleanup

Our complete collection of US and international mold standards references are collected at MOLD STANDARDS.

From the US EPA we include this more general advice on the criteria for a mold cleanup job: [Our comments are in brackets]

How Do I Know When the Remediation or Cleanup is Finished?

You must have completely fixed the water or moisture problem before the cleanup or remediation can be considered finished. [See MOLD PREVENTION GUIDE]
You should have completed mold removal. Visible mold and moldy odors should not be present. Please note that mold may cause staining and cosmetic damage. [See MOLD CLEANUP, VISUAL CHARACTERISTICS and see ACCEPTABLE MOLD LEVEL. Remember that no building is mold-free except perhaps inside of a manufacturing "clean room" - mold exists in air everywhere and small amounts of molds will be found in settled dust just about everywhere - don't set a target of "zero mold".]
You should have revisited the site(s) shortly after cleanup and it should show no signs of water damage or mold growth. See MOLD CLEARANCE TIMING.
People should have been able to occupy or re-occupy the area without health complaints or physical symptoms. [See MOLD RELATED ILLNESS GUIDE.]
Ultimately, this is a judgment call [and must include an understanding of the original location, extent, type, and cause of mold contamination that was to be removed as well as the chances of other mold contamination in the building that was not addressed]; there is no easy answer. If you have concerns or questions consult our Frequently Asked Questions database and ask a question [or Contact Us directly at InspectAPedia.com] if you don't find what you need.

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Technical Reviewers & References

Related Topics, found near the top of this page suggest articles closely related to this one.

[1] "A Brief Guide to Mold, Moisture, and Your Home", U.S. Environmental Protection Agency US EPA - includes basic advice for building owners, occupants, and mold cleanup operations. See http://www.epa.gov/mold/moldguide.htm
[2] US EPA - Mold Remediation in Schools and Commercial Building [Copy on file at /sickhouse/EPA_Mold_Remediation_in_Schools.pdf ] - US EPA
[3] US EPA - Una Breva Guia a Moho - Hongo [Copy on file as /sickhouse/EPA_Moho_Guia_sp.pdf - en Espanol
[4] G. A. Payne, W. C. Nierman, J. R. Wortman, B. L. Pritchard, D. Brown, R. A. Dean, D Bhatnagar, T. E. Cleveland, Masayuki Machida, & J. Yu, "Whole genome comparison of Aspergillus flavus and A. oryzae", Medical Mycology September 2006, 44, S9S11
Abstract: Aspergillus flavus is a plant and animal pathogen that also produces the potent carcinogen aflatoxin. Aspergillus oryzae is a closely related species that has been used for centuries in the food fermentation industry and is Generally Regarded As Safe (GRAS). Whole genome sequences for these two fungi are now complete, providing us with the opportunity to examine any genomic differences that may explain the different ecological niches of these two fungi, and perhaps to identify pathogenicity factors in A. flavus. These two fungi are very similar in genome size and number of predicted genes. The estimated genome size (36/8 Mb) and predicted number of genes (12 197) for A. flavus is similar to that of A. oryzae (36/7 Mb and 12 079, respectively). These two fungi have significantly larger genomes than Aspergillus nidulans (30/1) and Aspergillus fumigatus (29/4). The A. flavus and A. oryzae genomes are enriched in genes for secondary metabolism, but do not differ greatly from one another in the predicted number of polyketide synthases, nonribosomal peptide synthases or the number of genes coding for cytochrome P450 enzymes. A micro-scale analysis of the two fungi did show differences in DNA correspondence between the two species and in the number of transposable elements. Each species has approximately 350 unique genes. The high degree of sequence similarity between the two fungi suggests that they may be ecotypes of the same species and that A. oryzae has resulted from the domestication of A. flavus. Keywords aflatoxin, secondary metabolism, koji moulds
[5] Robert A. Blanchette & C. Gardner Shaw, "Associations among Bacteria, Yeasts, and Basidiomycetes During Wood Decay", Phytopathology 68: 631-637, also appearing in Ecology and Epidemiology.
Atlas of Clinical Fungi, 2nd Ed., GS deHoog, J Guarro, J Gene, & MJ Figueras, Centraalbureau voor Schimmelcultures, Universitat Rovira I Virgili, 2000, ISBN 90-70351-43-9 (you can buy this book at Amazon) - The Atlas of Clinical Fungi is also available on CD ROM
"A Brief Guide to Mold, Moisture, and Your Home", U.S. Environmental Protection Agency US EPA - includes basic advice for building owners, occupants, and mold cleanup operations. See http://www.epa.gov/mold/moldguide.htm
"Disease Prevention Program for Certain Vegetable Crops," David B. Langston, Jr., Extension Plant Pathologist - Vegetables, University of Georgia (PDF document) original source: www.reeis.usda.gov/web/crisprojectpages/209797.html
"Disease Prevention in Home Vegetable Gardens," Patricia Donald, Department of Plant Microbiology and Pathology, Lewis Jett
Department of Horticulture, University of Missouri Extension - extension.missouri.edu/publications/DisplayPub.aspx?P=G6202
"Management of Powdery Mildew, Leveillula taurica, in Greenhouse Peppers," Ministry of Agriculture and Lands, British Columbia - Original source: www.agf.gov.bc.ca/cropprot/peppermildew.htm
Fifth Kingdom, Bryce Kendrick, ISBN13: 9781585100224, is available from the InspectAPedia online bookstore - we recommend the CD-ROM version of this book. This 3rd/edition is a compact but comprehensive encyclopedia of all things mycological. Every aspect of the fungi, from aflatoxin to zppspores, with an accessible blend of verve and wit. The 24 chapters are filled with up-to-date information of classification, yeast, lichens, spore dispersal, allergies, ecology, genetics, plant pathology, predatory fungi, biological control, mutualistic symbioses with animals and plants, fungi as food, food spoilage and mycotoxins.
Fungi, Identifying Filamentous, A Clinical Laboratory Handbook, Guy St-Germain, Richard Summerbell, Star Publishing, 1996, ISBN 0-89863-177-7 (English) (buy at Amazon)
US EPA: Una Breva Guia a Moho - Hongo [Copy on file as /sickhouse/EPA_Moho_Guia_sp.pdf - en Espanol

"A Brief Guide to Mold, Moisture, and Your Home", U.S. Environmental Protection Agency US EPA - includes basic advice for building owners, occupants, and mold cleanup operations. See http://www.epa.gov/mold/moldguide.html
Thanks to reader Glenn A Wood, Coffey Geotechnics, 20 Meteor Drive Etobicoke Ontario M9W 1A4 Canada T +1 416 213 1255 T +1 877 796 7773 F +1 416 213 1260 C + 1 416 388 6647, email: Glenn_Wood@Coffey.com, for discussing mold clearance inspection procedures - September 2010

Books & Articles on Building & Environmental Inspection, Testing, Diagnosis, & Repair

Our recommended books about building & mechanical systems design, inspection, problem diagnosis, and repair, and about indoor environment and IAQ testing, diagnosis, and cleanup are at the InspectAPedia Bookstore. Also see our Book Reviews - InspectAPedia.

The Home Reference Book - the Encyclopedia of Homes, Carson Dunlop & Associates, Toronto, Ontario, 25th Ed., 2012, is a bound volume of more than 450 illustrated pages that assist home inspectors and home owners in the inspection and detection of problems on buildings. The text is intended as a reference guide to help building owners operate and maintain their home effectively. Field inspection worksheets are included at the back of the volume. Special Offer: For a 10% discount on any number of copies of the Home Reference Book purchased as a single order. Enter INSPECTAHRB in the order payment page "Promo/Redemption" space. InspectAPedia.com editor Daniel Friedman is a contributing author.

Or choose the The Home Reference eBook for PCs, Macs, Kindle, iPad, iPhone, or Android Smart Phones. Special Offer: For a 5% discount on any number of copies of the Home Reference eBook purchased as a single order. Enter INSPECTAEHRB in the order payment page "Promo/Redemption" space.

Building inspection education & report writing systems from Carson, Dunlop & Associates Ltd

Environmental Health & Investigation Bibliography - our technical library on indoor air quality inspection, testing, laboratory procedures, forensic microscopy, etc.
Kansas State University, department of plant pathology, extension plant pathology web page on wheat rust fungus: see http://www.oznet.ksu.edu/path-ext/factSheets/Wheat/Wheat%20Leaf%20Rust.asp
"A Brief Guide to Mold, Moisture, and Your Home", U.S. Environmental Protection Agency US EPA - includes basic advice for building owners, occupants, and mold cleanup operations. See http://www.epa.gov/mold/moldguide.htm
US EPA - Mold Remediation in Schools and Commercial Building [Copy on file at /sickhouse/EPA_Mold_Remediation_in_Schools.pdf ] - US EPA
US EPA - Una Breva Guia a Moho - Hongo [Copy on file as /sickhouse/EPA_Moho_Guia_sp.pdf - en Espanol


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