This document from a refinery and chemical processing plant details the risks associated with deadlegs, sections of piping where fluids become stagnant. The document explains how deadlegs can pose health, environmental, operational, and fire/explosion hazards, as stagnant fluids can accumulate hazardous materials, corrode the piping, and even react to form dangerous substances. The text outlines risk mitigation measures to prevent accidents, such as minimizing deadlegs during design, implementing regular inspections and cleaning, installing monitoring systems, and providing employee training and emergency preparedness.