Natural fibers (bio-fibers) from industrial processes waste; for example bovine hair from tannery industry, are an important source of bio-fiber as reinforcing agents due to their high aspect ratio and keratin content. Keratin is a hydrophobic biopolymer, contrary to cellulose which has a hydrophilic character; and it represents an advantage as reinforcing agent for different polymers. In this work, the effect of keratin fiber obtained from tannery industry waste and melamine borate as flame retardant additives on the resulting properties of starch base biopolymer has been studied. Starch base biopolymer with keratin fiber and melamine borate blends were processed by twin screw extrusion at different keratin fiber and melamine borate contents. Thermal stability of starch base biopolymer blends was evaluated by thermogravimetry analysis. Preliminary results have pointed out that keratin fiber and starch base biopolymer degrade through two main steps. With respect to char residue production, at 800°C, keratin fiber showed higher char residue (19.3 wt.-%) than starch base biopolymer (2.6 wt.-%). The combination of keratin fiber/melamine borate promotes the thermal stability of starch biopolymer and char residue production at low contents (3 and 5 wt.-% respectively). These results are promising to produce ecological flame retardants and to reduce high waste from the tannery industry.