Fogging | Uncategorized

The Case for Hot or Dry Fogging- Part 1

Cesar Collado
May 21, 2020

Reading Time: 9 minutes

Effectively Using DIY Botanical Fogging When Remediating Mold

By Cesar Collado

To begin with, this article is written to inform people who suffer, or family suffers, from mold sensitivity or chronic illness due to mold.  I am hoping to reach these patients and those whose physicians have prescribed to them that they either need to “get their home fixed” or “they need to move out and take nothing with them.”  Today I will discuss DIY options to reduce the mold counts in your home in order to breath higher quality indoor air while waiting for your home to be inspected and remediated.  This will also help you identify the source of mold by retesting the home several days after you fog.  This will mitigate the risk of an inspection suggesting more remediation than necessary which drives costs up significantly.

Unfortunately, the debilitating symptoms from mold exposure will not cease until airborne spores are removed from the indoor air, where according to the EPA people spend on average of 93% of their lives.

“The quality of the AIR you breathe in is 2 TIMES MORE IMPORTANT than your genetic code to your health.  The quality of the AIR you breathe in is 5 TIMES MORE IMPORTANT than all the treatment rendered by hospitals, doctors and medications!”                                                      


Rishi Manchanda MD. Ted Talk. September 14, 2014

For clarity, this means that if you do not remove the source of mold in your home, it is unlikely that you will get better due to living in as moldy home.  The body cannot heal if inhaled mold is continuously taxing your immune system.

About Mold:

Mold is ubiquitous, both inside and outside.  It is everywhere!  Its role is part of the normal decaying process in nature. We see it outdoors, in our bathrooms, and often in our refrigerators.  This is normal and we accept it.  When there is a moisture problem and water damages a home, today’s building materials create fertile ground for many dangerous mycotoxin producing molds such as Aspergillus, Penicillium, Stachybotrys, Alternaria, Fusarium, Trichoderma, Wallemia and others. Today, plaster walls are replaced with gypsum/paper-backed drywall.  Solid wood has been replaced with particle board products, and other furnishings contain cellulose or adhesives along with other toxic chemicals used as flame retardants.

Unfortunately, when mold contaminates a home, it is insidious, resilient, and difficult to completely eradicate from both decaying materials and the air.

Characteristics of  Mold:

  • Mold spores are tiny seed-like structures that grow in colonies as reproduction is essential for surviving. They are so small that we cannot see individual spores unless they are magnified 100x or more. A visible colony the size of a pin hold can have 250,000 spores.
  • Mold reproduces at a high rate when moisture meets a source of nutrients.
  • Mold spores are routinely released into the air. Similar to pollen, they can float for long periods of time and travel long distances when airborne due to a gentle breeze, or simple air ventilation, before settling. Imagine mold spreading like when a dandelion is blown.
  • If mold settles in any area that is moist and has oxygen, it will reproduce. Excessive humidity and water leaks combined with building materials made of paper-backed gypsum, particle boards, and cellulose are particularly vulnerable to mold decay, often from several mycotoxin producing species. In indoor environments, molds grow on moist surfaces such as the drywall, wallpaper, carpet, baseboards, and heating, ventilation and air-conditioning systems (HVACs). As these molds reproduce, they reach a point where they produce spores that can be released. The spores will become airborne after drying out or if disturbed.  We breathe in mold spores every day, indoors and outdoors. Usually these exposures do not present a health risk. However, health problems may result when people are exposed to large amounts of mold, particularly indoors.
  • The air in some working environments including moldy buildings may contain up to 1,000,000,000 spores per cubic meter of air.

The Physical or Mechanical Challenge of Remediating Airborne Mold

To completely remediate a home, mold must be removed from building materials as well as the breathable air.  Decaying materials cannot be  salvaged and must be removed all together.  The near impossible challenge is that in order to clean mold, it must be disturbed during the removal process.  When this occurs, airborne molds have the ability to contaminate other rooms in homes and possibly the HVAC system.  Professional remediators will often have to completely seal portions of the home and HVAC systems using specifically installed taped-down plastic sheets. They also either create negative pressure within the contained area funneling exhaust outside the home, or filter the air through a HEPA air scrubber.  Air scrubbers can only clean what goes through the HEPA filter, so disturbing mold while removing spores will not remove all spores. It is for this reason that we suggest hot fogging a home after remediation to polish areas in which all spores could not be removed, as well as to treat hidden mold sources that were not found during remediation.

Surprisingly, the dry or hot fogging innovation was originally developed by the entertainment industry for special effects during the 1970s using dry ice.  In fact, one of the preeminent fog machine producers in Germany, Gunter Schaidt, Safex Chemie GmbH, received an Academy Award in the category of Technology in Cinema (“Oscar”) for “non-toxic liquid for artificial fog” in 1984.  The entertainment industry has also worked closely with the EPA to establish safety by conducting an extensive scientific study, “Health Effects Evaluation Of Theatrical Smoke, Haze, And Pyrotechnics”.

Over the years, the use of fogging has been both studied and practiced in a variety of efforts.

  • 1942: Propylene glycol vapor demonstrates antibacterial properties.
  • Late 19th century: Fogging with formaldehyde was utilized prior to the EPA recognizing formaldehyde as a carcinogen.
  • 1971: Fog Machine created for the entertainment industry in Hollywood.
  • 2000s: The use of polyol-based fogging as a carrier for  disinfectant was being used to clean “Clean Rooms” across industries such as laboratories, micro-instrument production, and pharmaceutical manufacturing
  • Early 2000’s: The use of botanical fogging was established by building science professionals as an alternative to toxic chemicals that physicians’ patients could not tolerate.
  • 2010s: Fogging became used regularly used in the cleaning and disinfecting of a variety of industrial food cooking equipment as a means to disinfect without disassembly.
  • 2010s: Agency for Toxic Substances and Disease Registry published “Case Studies in Environmental Medicine (CSEM): Ethylene Glycol and Propylene Glycol Toxicity” which established a toxicity profile of ethylene glycol (Highly Toxic) and also established the safety of propylene glycol as Generally Regarded As Safe (GRAS) for use in food, pharmaceuticals, and cosmetics.

Because mold sensitive patients are often chemically sensitive, chemical disinfectants can be especially toxic or harmful to sensitive occupants.  Building science experts, indoor air quality experts, and a select number of remediators and HVAC pros that work with physicians will at times turn to natural products known for their antimicrobial activity.  Using a hot fogging method, they are able to physically remove mold from the air and surfaces rather than just kill the microbes and leave remaining debris and toxins in the air or on surfaces.

The Safety of Botanical Fogging

As mentioned earlier, propylene glycol fogging has been used in the entertainment business and as a necessary training tool for fire fighters, military, and other rescue professionals.  Hot fogging has been adopted by the pharmaceutical industries, hospitals, and food production for cleaning.  Hot fog is used when cleaning and sanitizing hospitals, clean rooms for manufacturing electronic components, and research labs. Fogging is also used with large scale food production equipment.  Prior to fogging, instruments would need to be disassembled after each use which is time consuming, expensive, and created opportunity costs.

The hot fog can reach everywhere in a room including holes, crevices, and beneath and around large furnishings.  Pressure manipulation in the form of positive and negative pressurization can be used to drive the fog into the near impossible to reach areas in a room or to funnel exhaust and airborne particles such as mold spores, bacteria, dust, and other microbes outdoors.

How Botanical Fogging Works

Mold, bacteria, and other microbes are social organisms.  In my article on Biofilms in Chronic Inflammation and Infections, I explain how diverse microorganisms form together with sugars to make a film that protects the microbes from any antimicrobial threats.  Read the article on Biofilms HERE.  This activity is called agglomeration. The small particle ions are attracted to other ions and cluster together.

Mold Remediation

The propylene glycol fog creates a fog or vapor with microscopic droplets that can rise to reach all areas in the room. The Haven Fogger Kits can disburse 1,500 (HavenFog Mini-Kit) to 20,000 (HavenFogger) cubic feet per minute into a room.  The fog is composed of heated mini-droplets of the botanical that are approximately 10 microns in size. Fogging at this rate allows the fog to become dense in the room to the degree that you cannot see through the fog.  The fog droplets are also social and adhere to the floating fragments & spores that continue the agglomeration.

By allowing the fog to settle over the periods of 12-24 hours, there is plenty of time for the botanicals to be directly exposed to the molecules for sufficient time and gravity pulls the particles, organisms, and debris to the floor or other horizontal surfaces.  The fog then evaporates, leaving a microscopic layer of the botanical.  The Propylene glycol used as a carrier is food grade and is regarded by the FDA as Generally Regarded As Safe (“GRAS”), and the microscopic layer left of the all-natural botanical is safe to the touch and for food preparation surfaces.  Following the settle time, a thorough cleaning of all surfaces must be done with a HEPA vacuum and surfaces wet wiped with microfiber cloths or disposable rags.

Mold Remediation

This activity can be likened to how a good rain can almost diminish pollenMold Remediation counts in the air. This photo illustrates how pollen is removed from the air during rain and gets captured in drainage.



The Importance of Cleaning Before and After Fogging

The primary purpose of a disinfectant or botanical fogging is to remove mold from the home.  Unfortunately, soil and dust can protect the mold, circulate it in the air, or disinfecting without prior cleaning can give a false sense of safety.  Clearing the room of all extra items that can collect dust is essential.  Disinfecting a room will kill microorganisms on surfaces; however, it will not necessarily address the airborne spores. Professional mold remediators who use disinfectants will properly seal the room and use negative air pressure and air scrubbers to remove the airborne particles. More importantly, exterminating the life of the mold organism does not completely eliminate the risk.  The debris and mycotoxins, which are toxic chemicals, remain harmful to humans.

If a surface is fogged before it is cleaned, the remaining soils can stillMold Remediation contribute to the growth of harmful microbes and lead to further contamination. The residual soils may also serve as a barrier, preventing the disinfectant or botanicals from reaching the surface and doing its job. Lingering soils on the surface may affect the active chemicals in a cleaning product, impacting their efficiency. If the surface is thoroughly cleaned first, the disinfection step becomes much more effective.

DIY Hot Fogging

DIY fogging takes time and effort, but it is a safe activity to do yourself to improve health and save money. DIY fogging will fully saturate the room with fog, which will agglomerate with the mold spores and other pollutants so they will fall to floor and horizontal surfaces.

A HEPA vacuum will remove virtually all of the biological debris and particles. (Note: it must be a HEPA Cannister vacuum designed for this purpose or an upright vacuum with HEPA specially designed bags.  Regular vacuums will not collect microscopic particles and will recirculate them into the air.  Bagless cannister vacuums create significant risk as you are exposed to an overwhelming number of toxic particles of dust when emptying.)  Mold spore debris is just as dangerous as mold spores when inhaled.

One benefit of hot fogging is that you do not have to remove all of the contents of the room to fog.  HavenFog will reach all of your items on all sides. It is recommended that individual items be cleaned with HavenClean or concentrated hydrogen peroxide.

biobalance fogger moldbiobalance fogger mold

DIY Misting

Cold fogging or misting is often used in a similar manner to the hot fog.  The cold fogger aerosolizes the liquid into droplets of approximately 25 microns in size.  The mister is limited to the spray pattern of the mist.  It will reach hard to reach places; however, it will not force itself into cracks, seams, and crevicbiobalance fogger moldes or the back side of objects being misted.  The HavenMist kit can be used for these purposes.   Misting still requires cleaning before and after if being used as a means to remediate. Given the limitations, misting can still be used very effectively. The HavenMister is recommended for regular maintenance of mold between annual or biannual hot fogging.   It is also effective in removing putrid and musty odors that come from bacteria, yeast, and mold.

If you would like to share your story or have a question, please feel free to comment on this article.



  1. Manchanda, Rishi MD. “The Air We Breathe”.  Ted Talk.  September 15, 2014
  2. Moline, Jacqueline MD et. al, Department of Community and Preventive Medicine Mount Sinai School of Medicine. “Health Effects Evaluation Of Theatrical Smoke, Haze, And Pyrotechnics”. Equity-League Pension and Health Trust Funds. June 6, 2000.
  3. Robertson, O. et. al. “The Bactericidal Action of Propylene Glycol Vapor On Microorganisms Suspended in Air.” Journal of Experimental Medicine. June 1, 1942.
  4. McNary, Dave. “Richard Glickman, Engineer and Fog Machine Inventor dies at 91. Variety. Feb 23 2018.
  5. “Science And Technical Oscars Awarded” Los Angeles Times. March 18, 1985
  6. Marlow, Jeffrey. “Microbes are More Social Than You Think, But Not Always in a Good Way” Discover.  August 22, 2016