Pressure safety low alarms (PSLs) have been required as a means of pipeline leak detection. PSLs are typically located on the export riser and on each boarding riser of intermediate platforms. The PSL is intended to shut in the production in the event of a pipeline leak. Historical production and leak event data suggest that PSL alarms may not function as expected in all operating situations. The US Minerals Management Service (MMS) commissioned a study to determine PSL operation as a function of produced fluids, line characteristics and other factors. This paper summarizes the findings of this study. The results of this study demonstrate situations in which PSLs can function as prescribed and situations in which PSLs may prove unreliable. The results of this study are significant because offshore pipelines are typically the greatest source of offshore pollution.