How to Get Rid of Mold Spores in the Air

Mold spores are tiny reproductive fungal cells that float through the air as microscopic particles looking for a favorable environment to establish new mold colonies.

These spores are normally present in the everyday air around us, even inside your home. According to Medical News Today, “all indoor environments have some mold spores in them, but this does not affect most people.”

Most of the time they aren’t harmful or dangerous to humans, but in high enough concentrations they may cause respiratory symptoms like sneezing, coughing, runny noses, and irritation.

People with mold allergies may experience more severe reactions.

Can You Get Rid of Mold Spores in the Air?

Mold spores are constantly all around us.

Due to their size (between 2-100 microns), they’re invisible to the naked eye and can stay in the air indefinitely. Even the smallest breeze can easily carry them great distances and into homes and buildings.

In fact, even the EPA’s website succinctly states that “mold spores cannot be eliminated from indoor environments.”

So what can you do if you’re suffering from health problems from mold spores?

While it’s not feasible to maintain a completely sterile environment free of mold spores, there are ways that you can significantly reduce the amount of mold spores in the air in your home.

How to Get Rid of Mold Spores in the Air

Using Air Purifiers

Air purifiers and air cleaners are devices that remove airborne pollutants from the air in your home, including mold spores.

In general, they work by drawing air into the system, which then passes through a series of filters designed to capture and remove microscopic particles from the air.

To use air purifiers to get rid of mold spores:

  1. Choose an air purifier with enough power for the size of the room(s) you want to get rid of mold spores from.
  2. Set up the air purifier in a location where it’s able to draw in dirty air and release purified air towards you.
  3. It can take around 30 minutes to several hours to clean the air in the room, depending on the air changes per hour (ACH) and clean air delivery rate (CADR) of the air purifier.
  4. Leave the air purifier running 24/7 to maintain clean air in your room. After the initial cleaning is complete, you can turn it down to a lower setting to save power.

You can turn off the air purifier if you’re away for an extended period of time; just be aware that mold spores may return to the air once the purifier stops running.

There are several types of air purifiers and air cleaners available:

  • Mechanical Air Filters (e.g. HEPA)
  • Electronic Air Filters (e.g. Ionizers)
  • Gas-Phase Air Filters (e.g. Activated Carbon)
  • UVGI (Ultraviolet Germicidal Irradiation) Cleaners
  • PCO (Photocatalytic Oxidation) Cleaners
  • Ozone Generators

Not all purifiers target the same pollutants. For example, mechanical and electronic air filters work best for removing small particles from the air, while gas-phase air filters and PCO cleaners are designed to eliminate gases and odors.

To get rid of mold spores, we recommend using air purifiers with:

  • Mechanical Air Filters
  • Electronic Air Filters
  • UVGI Cleaners
  • Ozone Generators

Specifically, air purifiers with HEPA (high-efficiency particulate air) filters work great at removing mold spores.

HEPA filters are considered to be rated MERV 17 or above, which means that the filters can trap more than 99.7% of air particles as small as 0.3-1.0 microns in size.

Some air purifiers use a combination of air filters and UVGI (UV light) or ozone to purify air and kill mold spores. While these models are typically more expensive, they offer greater cleaning power — and peace-of-mind.

Improving Ventilation

Improving ventilation in living areas may provide some quick relief if the mold spores in your home are a result of moisture issues or visible mold growth.

The principle behind this is to allow dirty indoor air to flow outside while allowing fresh air to flow inside.

  1. Open windows to let fresh air in (even for just 30 minutes a day).
  2. Place a fan next to the open window to help blow air outside.
  3. Cross ventilate rooms by opening interior doors opposite to the windows.
  4. When windows are closed, turn on air conditioning units or ceiling fans.
  5. If your home has a central HVAC system, set the fan to “on” to allow the fan to run continuously. Don’t forget to change air filters every 3 months.
  6. Use exhaust fans in kitchens, bathrooms, and laundry rooms.

Ultimately, this should equalize and lower the concentration of mold spores inside and outside to a level that’s harmless to humans.

However, ventilation by itself will not fully remove mold spores from the air. If you’re sensitive or allergic to mold spores, using an air purifier would be more effective at alleviating symptoms.

Fixing Conditions That Lead to Mold

Preventing mold from growing in the first place is the best way to keep the concentration of mold spores in the air at low levels.

Common causes of indoor mold growth include:

  • Plumbing leaks
  • Roof leaks
  • Flooding
  • Humidity
  • Condensation

The key to mold prevention is moisture control. Even small amounts of moisture can allow mold spores to germinate and take root in your home.

To prevent mold from growing and producing high concentrations of mold spores, here are some steps you can take:

  1. Promptly address any water problems (leaks, floods, spills). Fix the cause and dry the affected area thoroughly within 24 hours.
  2. Use dehumidifiers to keep relative humidity indoors between 30-50%.
  3. Utilize windows, doors, and exhaust fans to keep bathrooms and kitchens dry.
  4. Clean shower curtains and bathroom tiles regularly with mold-killing products.
  5. Vent appliances that produce moisture to the outside whenever possible.
  6. Keep air conditioning drip pans clean and dry.

For more information about mold prevention, read the EPA’s A Brief Guide to Mold, Moisture, and Your Home.

Mold Spore FAQs

Are mold spores dangerous?

Mold spores are normally present in the air in very low concentrations. They are usually harmless to most people. However, some people are more sensitive to mold spores than others, in which case prolonged exposure may lead to health problems. The most common symptoms are allergies and irritation.

Where do mold spores come from?

Mold spores are the reproductive cells of mold. They are so tiny and lightweight that they can float in the air indefinitely, and even a light breeze can carry them long distances.

In normal circumstances, they can enter your home through open windows, doorways, and ventilation systems. They can also be picked up and brought inside on clothing, objects, and pets.

How long do mold spores stay in the air?

Mold spores stay airborne indefinitely. While in the air, they remain in a dormant state until they come into contact with wet or moist surfaces, at which point they may start growing into visible mold.

Does bleach kill mold spores?

Bleach is a biocide that can kill mold on hard, non-porous surfaces, but bleach will not kill mold spores in the air. The EPA does not recommend using bleach as a routine practice for getting rid of mold spores.

Does hydrogen peroxide kill mold spores?

Hydrogen peroxide kills mold spore on contact by breaking down proteins and DNA. It’s normally used to clean mold on porous and non-porous surfaces. Ionized hydrogen peroxide can kill mold spores in the air, but it requires the use of a special fogging machine.

Does Lysol kill mold spores?

The active ingredient in most Lysol disinfectant sprays is benzalkonium chloride (BAC), a quaternary ammonium compound with antifungal properties. Lysol is designed to kill mold and mold spores on surfaces — it is not effective at killing mold spores in the air.

Does vinegar kill mold spores?

Vinegar is a natural alternative that can kill mold on porous and nonporous surfaces. However, spraying vinegar is not an effective way to kill mold spores in the air.

Will a dehumidifier kill mold spores?

Dehumidifiers do not kill or remove mold spores already in the air, but they can help prevent them from growing and spreading indoors by keeping relative humidity levels low.

About Green Orchard Group

Green Orchard Group is an environmental health and safety firm based in New York City. We have over 25 years of experience as specialists in mold and indoor air quality services.