The U.S. Chemical Safety and Hazard Investigation Board (CSB) is urging the refining industry to eliminate the type of atmospheric vents that caused an explosion that killed 15 workers at BP's Texas City refinery in March 2005. The accident occurred during the start-up of the 460,000 bbl/day refinery's octane-boosting isomerization unit, when a distillation tower and blow-down drums were overfilled with flammable liquid hydrocarbons. The blow-down drum vented directly into the atmosphere, releasing highly flammable liquid vapor onto the refinery grounds, causing a series of explosions. The CSB is urging the American Petroleum Institute to change its recommended practices to warn the refining industry against using blow-down drums similar to those at Texas City, to use safer flare systems, and to ensure that companies plan for large-scale, flammable liquid releases from process equipment. In addition to those safety recommendations, the CSB is urging OSHA to establish a program promoting the elimination of unsafe blow-down systems. "Unfortunately, the weaknesses in design, equipment, programs, and safety investment that were identified in Texas City are not unique either to that refinery or to BP," says Carolyn Merritt, CSB chairman. "Federal regulators and the industry itself should take prompt action to make sure that similar unsafe conditions do not exist elsewhere." In late October, the CSB issued its preliminary findings that indicated BP was aware of several safety issues at the Texas City refinery but failed to act upon them quickly enough. A final report is expected early next year.