The xylanase used in this study was produced by a submerged fermentation of Fusarium venenatum and contained a gene code originating from Thermomyces lanuginosus. The enzyme was subject to a 13-week toxicological test in rats and in vitro tests to document its safety in use. The enzyme is to be applied as a processing aid in the baking industry to improve handling and stability of dough. The enzyme was not found to be mutagenic in the Salmonella typhimurium reverse mutation assay, nor did it cause chromosomal aberrations in cultured human lymphocytes. Oral administration to rats of up to 10.0 ml/kg bw/day (equivalent to a Total Organic Solids dosage of 1.12 g/kg bw/day or a xylanase dosage of 89422 FXU(W)/kg bw/day) for 13 weeks did not cause any adverse effect.