The objective of the research was to evaluate the use of organic and inorganic floating covers to reduce odor emissions from swine waste storage units. Twenty-one 600 litre tanks containing approximately 8% total solids where examined with five potental treatments: no cover, wheat straw (12 in. thick), a 2 cm thick layer of soybean oil, 30 cm straw and oil mat (by placing straw in 4 layers with 1.3 gal of oil between each layer and a Permalon cover.