A B-side component of a two component low pressure polyurethane foam, the B-side component includes: a fluoride ion scavenger; one or more polyols consisting of all polyether polyols and, if the fluoride ion scavenger is a polyol, the fluoride ion scavenger, and no polyester polyols; at least one silicone polyether surfactant; at least one flame retardant and/or plasticizer; a catalyst package comprising an amine catalyst; and an HFO propellant consisting of 1,3,3,3-tetrafluoropropene and no other HFO propellant. Water is in an amount of less than 1% by weight of the B-side prior to inclusion of the HFO propellant at the B-side.