Identifying Mold

It Sometimes Takes a Village to Address All Mold Issues in a Home

Cesar Collado
November 18, 2021

Reading Time: 7 minutes

During a problem-solving session with colleagues, we addressed not only a difficult mold problem, but also the many uses of hot fogging.

While we discuss Hot Fogging as one of the best alternatives to addressing systemic mold problems in homes or buildings, the fog also provides diagnostic benefits to a remediator and is one alternative amongst other fogging solution that may not be good solutions for the home or health.

Below is an example from a Bau-Biologist (building scientists) in my network while serving a client, who is also a practicing physician and the patient. Bau-Biologists are specifically trained building scientists who study and apprentice in all aspects of building health and indoor air quality and impact on human health.  I participate in this problem-solving network of building scientists addressing indoor air quality fixes when these services are prescribed by physicians as essential for a patient’s health.  This is just an example of how it often takes input across multiple disciplines to find the optimal solutions.  Often, a physician, mold remediator, and/or HVAC professional may not have the same understanding of the mold illness, mitigation techniques, mold diagnostics, safety protocols, and tools.  Articles like this provide insight and emphasize the amount of diligence required to get your home safe and get well.


Question from Building Scientist:


A very experienced Bau-Biologist (a building scientist) had a client who was  a medical practitioner renting a suite in a strip mall building. She is mold sensitized. HVAC units are on the rooftop. She inspected and tested the unit serving her suite. Visually it looked clean and well maintained, the drip pan looked ok, but the drainpipe was blocked with debris, slime, gunk …  Lab results for the coil, drip pan and plenum liner came back clean but the swab culture from the drainpipe was positive for molds (Penicillium), bacteria (staph), and yeasts. She normally does not  test drainpipes but since it was clogged and everything else looked good, she tested the one thing that was visually questionable.

The Physician is convinced the HVAC system in her suite is causing chronic sinus infections. Certainly, if she was being exposed to the organisms gleaned from that one culture, she could be right, but the question is: is it possible for occupants to be exposed to organisms living in the drainpipe? There have been numerous occasions of people getting sick from the slime and yeasts in the drip pan, so I know that’s feasible.  But can it be the drainpipe?

A Moldy, Clogged HVAC Condensation Drain Pipe

She recalled reading a study somewhere that – in some cases – QPCR testing had confirmed that molds from the condensate removal pump reservoir DID make their way to occupied spaces, so if THAT is possible, could there be exposure from the drainpipe? It might explain some of these unsolved cases.

This is remarkable that one of the most experienced and well credentialed building scientists in the country and has the humility to know what she doesn’t know and looks to other IAQ experts (In this case an HVAC specialist) for additional expert opinions and perspective.

Response From a Colleague:

The most important thing to do is check to see if there is some type of negative pressure that would allow contaminants to come back through the drain line to the office. Check with the drain line open and clogged.  “Smoke test” the unit running and without it running. Also turn any bathroom fans on for a worst-case scenario.

I have had projects where odors come into the building from situations like this so it’s possible. It may help if you are able to determine what organism is causing the sinus infections. Have they cultured the sinus of those with the issue?

These professionals can look to the mold identity to tell them more about the level of contamination, location, and potential illnesses or symptoms that may be related.

Also are the sinus infections occurring in staff or patients? I assume she has one, what about the others working in the area?

My Suggestion:

Since it is a medical practice and she has chronic sinusitis, indoor hot fogging would be an excellent alternative to remove mold, but also identify leaks in the HVAC and building.

 There are Multiple Reasons to Hot Fog.

Similar to smoke test in the HVAC, one of the benefits to hot fogging is identifying the now visible leaks where the fog escapes.  In addition, the fog penetrates the entire home/building including furnishings.  It is non-toxic, odorless, and evaporates fully over time.  The foggers pump an enormous volume in the space to penetrate cracks and crevices.

My suggestion of hot fogging was driven by the fact that the patient is still having symptoms after the fix.  Sometimes, getting all the mold issues remediated takes time.  Fogging addresses systemic mold problems immediately and will decrease the mold count in the home to close to zero. This makes the home livable until any physical destruction and removal occur. Maintenance cold fogging can be done as maintenance to keep mold counts down, as this is a more cost effective and less intrusive process.

Also, since your client is getting sinus surgery, she might benefit from suggesting to her surgeon to open and clean all her sinuses utilizing amphotericin b, the potent antifungal, “topically” in the sinuses.  (Most ENTs don’t think of amphotericin due to toxicity profile); however, it is a minimal dose and does not get absorbed into bloodstream so it isn’t metabolized by the liver and doesn’t have the tox profile.  It is like pressure washing your sinuses with potent cleaners and addresses biofilm as well.

It is a challenge to find a physician who regularly uses this technique.  You may have to do some calling around or searching for a physician.  Keep in mind that the procedure creates no risk to the surgery and any ENT can agree to perform the surgery.  You must also consider that if you elect to find a physician outside your network, your personal share of your coinsurance will differ than in-network percentage and can cost in the tens of thousands of dollars.

The Building Scientist’s Response:

Thanks Cesar! Are you suggesting fogging with [Biobalance Haven Fog] or something else? Also, what did you think of that article that was circulating regarding the fogging being detrimental to electronics and other items in the home? The EPA studies focused on Hydrogen Peroxide and Peracetic Acid; but they did determine a good amount of damage to computers, cell phones, etc. The peracetic acid is highly corrosive so maybe that doesn’t compare to Bio-Balance. Do we know the level of corrosivity in BioBalance Haven Fog?

Speaking of peracetic acid, one of my clients who is extremely mold-sensitive gave up trying to get rid of all the mold in his house on the lake. After several remediation efforts the symptoms kept coming back so he resorted to fogging with peracetic acid. He got relief for about 6 months then symptoms returned so he keeps doing it and is very happy with the treatment; but it must be repeated every 6-9 months.

Haven Mist by BioBalance can be used as a non-toxic option for periodic mold maintenance effectively.  Haven Fog is not a corrosive at all.  I have checked with the company and there have been zero complaints regarding any electronics damaged by fogging.

I always recommend mold removal/remediation and I had warned him it would be temporary but for him, it was the right solution because the mold issues in the house were chronic due to design and the only other option was tearing down the house. Personally, I would probably react to the peracetic acid and not tolerate being in the house!

Sometimes, any solution that can keep a patient from being ill is the best solution.  This suggestion, while different from Bio-Balance Fog Kit, provides a band aid solution while the moisture source is being removed or repaired and all the existing mold is being removed.


My Second Response:

BioBalance Haven Fog is my suggestion.  The delivery vehicle for the active ingredient is food grade propylene glycol via a hot fogging machine.  I have personally never heard of electronics getting damaged over the years.  In that case, I would conservatively suggest they clean electronics with a HEPA vacuum separately, or air wash using compressed air outdoors, or use Remedy Mold Spray or HavenMist wiping with a microfiber cloth.  However, I know several mold professionals and remediators have been fogging for over a decade.  You also get the benefit of identifying leaks via visual smoke outside the home/building if you fog.

Another benefit of fogging, leaks or gpas in a home can be identified. 

Discussion and Thoughts:

I share this string of communications to demonstrate the breadth of professionals involved in the planning of a specific treatment for a home or office.  In this case, an environmental specialist sought feedback from other professionals including mold inspectors, building scientists, HVAC experts, cleaning product chemistry, and environmental medical knowledge.  With the burden falling on the patient to get the proper home treatment that addresses their illness and symptoms.  Doing research surrounding all the players involved or seeking multiple professionals’ input can lead to better, more customized solutions.  In the long run, this saves money as a failed mold remediation attempt usually becomes a sunk cost with the same problem remaining.   Your home is making you sick.

I will continue to share these real-life examples to illustrate the complexity of securing your home from mold infestation.

 If you have any comments to share, please do!  If you have questions about the article, you can email me at