Endurance BioBarrier’s Mold Prevention Spray offers a 10-year guarantee. This spray is nontoxic, noncorrosive, nonflammable, and has zero volatile organic compounds (VOCs). To apply, simply remove a system’s air filter, turn on the fan, and administer using a fogger through the return vents. Mist coming out of the supply vents indicates the application is nearly finished. Supply side mist is actually an added benefit because it safely protects surfaces it contacts in that room, including carpets and upholstery. The spray creates an invisible, odorless barrier when dry — in about one hour — and also offers long-lasting protection against mold, mildew, germs, and musty odors when sprayed or fogged onto the outside of clean ductwork and in attics.