RS-100 is a water-based spray sealant engineered to seal joints, penetrations and seams from inside of the HVAC ductwork. The superior physical properties of this non-tack sealant will meet and exceed the SMACNA pressure classes and its flexibility allows for system operation without cracking. RS-100 sealant is formulated with EPA registered chemicals to resist microbial growth on the surface of the sealant.