When sprayed in a place, Icynene expands completely, filling all cavities and voids and creating a sealed building envelope, which eliminates air leakage/infiltration. Air leakage/infiltration accounts for up to 50% of heat loss from a building. Unlike other foams, Icynene’s unique polyicynene formulation is 100% water blown and therefore contains no harmful agents, volatile organic chemicals, HCFCs, HFAs, HFCs or formaldehyde. Icynene has been successfully tested and certified for applications directly to the underside of breathable and non-breathable roof membranes and felts and recently received BBA certification for this application. Icynene absorbs the lowest amount of moisture and has the highest level of vapour resistivity of any soft foam on the market.