The Centrifuge Facility will provide a life sciences research laboratory for rodents and plants on the space station. During a 90-day experiment increment, soiled waste trays from the rodent habitats must be safely stored. The present tests investigated what gases are generated and what bacteria survive during long-term storage of rodent waste and waste tray materials.Soiled filter material from flight and ground control Animal Enclosure Modules (AEM) flown on STS-54 in January, 1993 and from the Research Animal Holding Facility (RAHF) flown on Spacelab Life Sciences - 2 (SLS-2) in October, 1993 were placed in individual air-tight glass test vessels. Gas samples were withdrawn from each vessel and analyzed for a target list of volatile organics, odiferous compounds and methane using a GC/MS and detector tubes.No target compounds were detected in any of the AEM or RAHF samples. Ammonia, methane and some non-target compounds were detected in one AEM sample and the RAHF samples. Pressure measurements indicated that no gasses accumulated during storage. Microbial analysis showed a preponderance of environmental and human-related bacteria.These data suggest that rodent waste materials may be stored for long periods of time with little potential for generation of waste gasses or growth of bacteria harmful to humans.