The finishing of fabrics with flame retardants can reduce the tendency to burn or reduce the tendency to propagate the flame. The flame retardants may char the fuel, quench the reaction of combustion, absorb heat or emit cooling gases or replace oxygen. Flame retardants are durable or nondurable. Durable retardants include decabromodiphenyl oxide, antimony oxide, phosphates, brominated esters, PVC and other chlorinated binders. Nondurables include borates, boric acids, zinc borate, sulfuric acid sulfa mates, ammonium phosphates, urea, etc. Hydrated alumina and zinc borate act as smoke suppressants. Problems in the application include odor, yellowing, loss of tensile strength, stiffening, skin irritation and color change or loss.