Understanding Antimicrobial Chemicals Used In HVAC System Duct Cleaning

If your home's heating and cooling system's air ducts are in need of cleaning, then it is important that you understand the basics about how an antimicrobial chemical application can help to reduce harmful allergens in your home's HVAC system.

Antimicrobial Chemical Application

After your home's ductwork is thoroughly cleaned and vacuumed, you will have the option to have the area treated with an antimicrobial agent. Antimicrobials are applied in the following ways:

  • sprayed into the ducts
  • hand-wiped into the ducts
  • fogged into the ducts

Spraying and hand wipe applications are good options, but for a more thorough coverage you should request the fogging option. Fogging works in the same way as a bug bomb works to kill bugs in your home. The fogger is activated and then it sends small particles all the way through the ductwork, giving a nice even application.

Advantages of Antimicrobial Chemicals

Antimicrobial chemicals that are approved for use in HVAC ducting are effective at reducing the incidence of future growth and colonization of:

  • bacteria
  • fungi
  • mold

In addition, the antimicrobial chemical application will also deodorize the duct work. This will help to reduce musty smells and any odors coming from your home's HVAC system.

Home Occupancy During the Application of Antimicrobial Chemicals

While antimicrobial chemicals that are approved for use in HVAC systems are not harmful to humans or pets, you should leave your home during the time the ductwork is being cleaned. This will help prevent you from inhaling material that is being removed from the ducts. In addition, for antimicrobial chemical applications, you should stay out of your home for four to six hours after the chemical has been fogged into the ducts. This will keep your exposure to the chemicals to an absolute minimum.

Note: The United States Environmental Protection Agency (EPA) regulates antimicrobial chemicals under its pesticide rules. To verify that the antimicrobial your HVAC contractor recommends for use in your ductwork is approved for use in your home's air ducts, you should always ask to see the container and check for the EPA approval language on the label.


As you can clearly see, the application of an EPA-approved antimicrobial agent inside of your home's ductwork can help to reduce harmful bacteria, fungi, and mold. If you have any additional questions about the duct cleaning process, then you should contact a duct cleaning service in your city or town.