One phase of the Joint District, Federal and State Project for the Evaluation of Refinery Emissions was the study of hydrocarbon leakage from seals on pumps and compressors. The report details the techniques and conclusions of the study. Using the census data, pumps were classified into 27 unique combinations of pump type, seal type, product and pump operation. Approximately 15 per cent of the seals in each group were checked. A total of 473 pump seals were inspected and these had an average loss of 4.2 pounds of hydrocarbons per day. This average loss is based on emissions from 75 measured leaks and loss estimates for 95 small leaks. All compressor seals were tested. These lost an average of 8.5 pounds per day per seal. The hydrocarbon leakage from pump seals is given. (Author Modified Abstract)