The structural and functional components of high temperature lubrication systems are metal assemblies, lubricants and elastomeric seals. How do combinations of these effect each other under the varying conditions of temperature and atmosphere? This question is often presented to the manufacturers of seals and of lubricants. A laboratory method for determining the answer is presented here. This method exposes combinations of lubricant, metal and elastomer to varying atmospheric conditions at a constant temperature. The degrading effects of temperature alone on each component of a lubricating system are known. This work was prepared to show that the proper selection of the sealing system components can prolong the life of the system.Contributed by the ASLE Technical Committee on Seals and Packings and presented at the Annual Meeting of the American Society of Lubrication Engineers held in Cincinnati, Ohio, April 1960.