Abstract: There are disclosed a flame retardant for treatment of wood and a wood product coated with the flame retardent, which comprises (A) 3-(dialkylphosphono)propionamides respresented by the following general formula: ##STR1## (in which R.sub.1 and R.sub.2 each represents an alkyl group containing 1 to 3 carbon atoms; and R.sub.3 represents a hydrogen atom, a methyl group or a methylol group group) and/or methylolated derivatives thereof; (B) at least one resin selected from the group consisting of water-soluble or water-dispersible resins, melamine resins and copolycondensated urea-melamine resins; and (C) ammonium polyphosphates microcapsulated by melamine and/or epoxy resins.

Abstract: A fire retardent for woody materials, which is an aqueous solution comprising 100 parts by weight as solids content of a water-soluble 3-(dialkylphosphonopropionamide) represented by the following general formula ##STR1## wherein each of R.sub.1 and R.sub.2 represents an alkyl group having 1 to 3 carbon atoms, and R.sub.3 represents a hyrogen atom or a methyl group, and at least 100 parts by weight as solids of a water-soluble melamine resin as essential ingredients and having a pH of not more than 3.