A phosphorus containing flame retardant comprising the reaction product of a reaction mixture comprising: (a) at least one active hydrogen-containing compound selected from the group of: (i) a first polyol having a hydroxyl functionality of at least 3 and comprising at least one polyoxalkylene polyol having an equivalent weight 60 - 2500 g/mol; (ii) a polyamine having an amine functionality of at least 2 and having the structure given in Formula: H 2 N-(CH 2) n -[N -(CH 2) p] y -NH 2 with n and p being independently integers from 2 to 6, R is hydrogen or a hydroxyalkyl having 2-6 carbon atoms, and y being an integer from 0 to 25; and (iii) an amino alcohol having a combined amine and hydroxyl functionality of at least 2 and having the structure given in Formula: H m A-(CH 2) n -[N -(CH 2) p] y -AH m with n and p being independently integers from 2 to 6, R is hydrogen or a hydroxyalkyl having 2-6 carbon atoms, y being an integer from 0 to 25, A is independently nitrogen or oxygen, with at least one A being oxygen, and m being 2 when A is nitrogen and 1 when A is oxygen; and (b) at least one phosphorus containing compound having the general formula, or combination thereof: wherein X is a leaving group, R 1 and R 2 are, independently of one another, a C 1 -C 8 -alkyl, C 1 -C 4 -alkoxyethyl, C 1 -C 4 -alkyl-substituted C 6 -C 10 -aryl radical, alkyl substituted aryl, aryl substituted alkyl, nitro alkyl, hydroxyl alkyl, alkoxy alkyl, hydroxyl alkoxyalkyl, or R 1 and R 2 together form R in a six-membered ring, wherein the six membered ring has the general formula, or combination thereof: wherein R is a linear or branched divalent alkylene group containing from 3 to 9 carbon atoms. (a) at least one active hydrogen-containing compound selected from the group of: (i) a first polyol having a hydroxyl functionality of at least 3 and comprising at least one polyoxalkylene polyol having an equivalent weight 60 - 2500 g/mol; (ii) a polyamine having an amine functionality of at least 2 and having the structure given in Formula: H 2 N-(CH 2) n -[N -(CH 2) p] y -NH 2 with n and p being independently integers from 2 to 6, R is hydrogen or a hydroxyalkyl having 2-6 carbon atoms, and y being an integer from 0 to 25; and (iii) an amino alcohol having a combined amine and hydroxyl functionality of at least 2 and having the structure given in Formula: H m A-(CH 2) n -[N -(CH 2) p] y -AH m with n and p being independently integers from 2 to 6, R is hydrogen or a hydroxyalkyl having 2-6 carbon atoms, y being an integer from 0 to 25, A is independently nitrogen or oxygen, with at least one A being oxygen, and m being 2 when A is nitrogen and 1 when A is oxygen; and (i) a first polyol having a hydroxyl functionality of at least 3 and comprising at least one polyoxalkylene polyol having an equivalent weight 60 - 2500 g/mol; (ii) a polyamine having an amine functionality of at least 2 and having the structure given in Formula: H 2 N-(CH 2) n -[N -(CH 2) p] y -NH 2 with n and p being independently integers from 2 to 6, R is hydrogen or a hydroxyalkyl having 2-6 carbon atoms, and y being an integer from 0 to 25; and (iii) an amino alcohol having a combined amine and hydroxyl functionality of at least 2 and having the structure given in Formula: H m A-(CH 2) n -[N -(CH 2) p] y -AH m with n and p being independently integers from 2 to 6, R is hydrogen or a hydroxyalkyl having 2-6 carbon atoms, y being an integer from 0 to 25, A is independently nitrogen or oxygen, with at least one A being oxygen, and m being 2 when A is nitrogen and 1 when A is oxygen; and (b) at least one phosphorus containing compound having the general formula, or combination thereof: wherein X is a leaving group, R 1 and R 2 are, independently of one another, a C 1 -C 8 -alkyl, C 1 -C 4 -alkoxyethyl, C 1 -C 4 -alkyl-substituted C 6 -C 10 -aryl radical, alkyl substituted aryl, aryl substituted alkyl, nitro alkyl, hydroxyl alkyl, alkoxy alkyl, hydroxyl alkoxyalkyl, or R 1 and R 2 together form R in a six-membered ring, wherein the six membered ring has the general formula, or combination thereof: wherein R is a linear or branched divalent alkylene group containing from 3 to 9 carbon atoms.