HPP HYPO Surface conditioning THPS Tetrakis[hydroxymethyl]snium Sulfate Biocide THPC Tetrakis[hydroxymethyl]snium chloride Fire retardant Tetrakis[hydroxymethyl]snium Sulfate Urea Fire retardant THPC-UREA Tetrakis[hydroxymethyl]snium chloride Urea Fire retardant SNIC ACID Hyposrous Acid Reductant