A series of experiments was conducted to determine the relative safety of two hatching eggsanitizing chemicals on embryo viability. On 4 consecutive d, broiler breeder hatching eggs were sanitized after collection and sorting with BioSentry 904 or Bio-Phene at 1, 2, 6, and 12 times the recommended concentration. A total of 304 eggs per treatment (76/d) was sprayed with 8 oz (240 mL) of solutions containing ½, 1, 3, and 6 oz/gal concentrations of chemical, or controls of water, or nothing at all. Hatchability linearly decreased with increasing concentrations of BioSentry 904 due to early embryo mortality prior to Day 7 of incubation. Hatchability of eggs set was markedly decreased for eggs sanitized with BioSentry 904 at 3 and 6 oz/gal (84.4 and 78.2%, respectively). Hatchability of fertile eggs sanitized with Bio-Phene at ½, 1, 3, and 6 oz/gal concentrations were not significantly different (87.1 to 91.0%) when compared to the nonsprayed (88.7%) and watersprayed controls (88.7%). Hatched chick quality of eggs sprayed with Bio-Phene or BioSentry 904 with ½ to 6 oz per gal was comparable to the controls.