Question: How does mold become airborne?
In indoor environments mold will grow on moist surfaces such as the drywall, wallpaper, carpet, baseboards, and heating, ventilation and air-conditioning systems. As the mold grows, a stage is reached when it will produce spores. The spores then become airborne (aerosolized) after drying out or if they are disturbed.
Question: Can air duct systems become contaminated with mold?
Yes, air duct systems can become contaminated with mold, either by supporting mold growth inside (e.g., from a dirty or clogged air conditioning pan, due to over-humidification of system, etc.) or by being a means of circulating and distributing spores from one location to other parts of the home.
Question: Should I have my ducts cleaned?
That depends on the results to the air sampling that was taken in your home. If the airborne levels of moldare high in the home, we always recommend the Air Duct System be cleaned and sanitized.
Question: I have mold in my basement but no one ever goes down there. Can this be a problem?
Yes. It is possible that contaminants can enter small openings in the ventilation system and be distributed to other parts of the home.
Question: Can ozone air cleaners improve or reduce odor or pollution levels?
Some air cleaners are designed to produce ozone. Ozone is a strong oxidizing agent used as a disinfectant for water and sometimes to eliminate odors. However, ozone is a known lung irritant. Symptoms associated with exposure include cough, chest pain, and eye, nose and throat irritation. Ozone generators have been shown to generate indoor levels above the safe limit. Furthermore, it has been demonstrated that ozone is not effective in controlling molds and fungi, even at high concentrations far above safe health levels. Also ozone may damage materials in the home. For these reasons, the EPA strongly recommends that you do not use an ozone air cleaner in any occupied residential space.
Question: Can ozone air cleaners be used in unoccupied spaces?
They are sometimes promoted to treat homes, furniture and clothing after fires to remove smoke odors. Ozone is a strong oxidizer that will accelerate the degradation of rubber, upholstery, paints and other materials. Hence even when used in unoccupied areas, ozone generators can cause damage to building materials and electronic devices. the use of Air Scrubbers is a much safer way to remove airborne mold contamination.
Question: What are the most common signs that mold has become airborne in a home?
Because mold spores are microscopic, you cannot see them in the air. However, key indicators of an airborne mold problem include a persistent musty or earthy odor, a noticeable increase in allergy-like symptoms (such as sneezing, coughing, or watery eyes) when inside the property, and the rapid settlement of fine dust-like particles on surfaces shortly after cleaning.
Question: How long can mold spores remain suspended in the indoor air?
Airborne mold spores are incredibly light and can remain suspended in the air for hours, or even days, depending on the air movement within your home. In a stagnant room, settling takes time, but any routine activity—such as walking across a carpet, sitting on a couch, or turning on a ceiling fan—creates enough airflow to launch settled spores back into the air.
Question: Is a visual inspection enough to rule out an airborne mold problem?
No. A visual inspection is highly effective for identifying physical contamination, but it cannot determine the concentration of spores suspended in the air. Airborne mold can exist in high volumes due to hidden growth behind drywall, under flooring, or within the HVAC system. Air sampling is the only definitive way to measure and verify indoor airborne spore counts and any health risks associated with it.
Question: What is the difference between surface mold and airborne mold?
Surface mold refers to the visible, active fungal growth rooted into a structural material (like drywall or wood). Airborne mold consists of the microscopic reproductive spores and fragments that have detached from the surface growth and are floating through the air. While surface mold damages materials, airborne mold is the primary vehicle for cross-contamination and respiratory exposure.
Question: How does relative humidity affect airborne mold levels?
High relative humidity (above 60%) creates the ideal environment for surface mold to thrive and produce new spores. Conversely, when a space dries out quickly, some mold species release massive amounts of spores into the air as a survival mechanism to disperse and find moisture elsewhere. Maintaining indoor humidity between 35% and 50% is critical to keeping mold dormant.
Question: Can a standard furnace filter clear mold spores from the air?
Standard, low-cost fiberglass filters are designed to protect the HVAC equipment from large dust particles, not to purify the air. They are highly ineffective at capturing microscopic mold spores. To significantly reduce airborne spores, you need a filter with a minimum efficiency reporting value of MERV 11 or higher, or a dedicated HEPA (High-Efficiency Particulate Air) filtration system.
Question: What is the role of an Air Scrubber in removing airborne mold?
An Air Scrubber is a portable filtration system used by mold removal professionals during remediation services. It continuously draws in the room’s air, passes it through a series of filters—including a certified HEPA filter capable of capturing $99.97% of particles down to 0.3 microns—and exhausts clean air. This creates a “negative pressure” environment that prevents airborne spores from escaping into unaffected areas of the building.
Question: Why do mold remediation professionals set up plastic containment containment zones?
When contamination is disturbed during the mold removal process, millions of spores instantly become aerosolized. Containment barriers (heavy-duty plastic sheeting) are erected to isolate the work area. Combined with negative air pressure, this ensures that the highly concentrated airborne spores generated during the cleanup process do not drift into clean, unaffected parts of the home or office.
Question: Can airborne mold transfer from one room to another without an HVAC system?
Yes. While forced-air HVAC systems are the fastest disruptors, airborne mold spores can easily migrate through natural air currents, pressure differentials between rooms, open doors, and even the “stack effect” (where warm air rises and pulls air up from basements or crawl spaces into the upper living areas).
Question: How do you know when airborne mold has been successfully remediated?
Success is verified through Post-Remediation Verification (PRV) testing, commonly known as “clearance testing.” An independent professional collects air samples inside the contained work area after cleaning is complete. The airborne spore types and concentrations inside must be lower than, or similar to, an outdoor control sample and a non-affected indoor area to pass.
