Odor is a subject of growing public concern. Implementation of a odor control strategy can significantly reduce the level of offensive odor generated from and intensive livestock operation. Commerical pit additives are one alternative in the fight to reduce odor. This study examined the effectiveness of commercial pit additives for odor reduction effectiveness. Odors were tested through olfacrometry( A panle of four individual smell mixtures of odorous air from cylinders diluted by specifice amounts of fresh air. Dilution rates were adjusted until all panel members detect some odor, the odor threshold. A 0 to 87 percent reduction in the odor threshold was found with various responses to volatile fatty acids, pH, total nitrogen and ammonia nitrogen.