By regulatory exception, the Federal pipeline safety standards governing hazardous liquid pipelines do not apply to pipelines operated at a stress level of 20 percent or less of the specified minimum yield strength (SMYS) of the pipe. In this Notice of Proposed Rulemaking (NPRM), the Research and Special Programs Administration (RSPA) proposes to revise the current exception and to apply the pipeline safety standards to certain pipelines operating at a stress level of 20 percent or less of SMYS. RSPA expects that this rulemaking will improve public safety and environmental protection by minimizing the possibility of accidents.