Processing Magazine

Hot weather played role in Praxair fire

June 19, 2006

Investigators have found that extremely hot weather was partly to blame for a fire that caused massive explosions last June at a compressed gas facility in St. Louis owned by Praxair Inc., the Associated Press reports. The U.S. Chemical Safety and Hazard Investigation Board issued a safety bulletin last Thursday aimed at avoiding fires at facilities like Praxair''s. Among the findings, the CSB found that when exposed to extreme heat and sunlight, propylene cylinders can vent gas through relief valves which can then ignite. The board does not have authority to issue fines or citations. The board recommended that compressed gas companies change relief valves on propylene cylinders to avoid too much pressure in them. Hall said about 50,000 cylinders exist. By comparison, there are about 50 million cylinders of propane. Praxair disputed the findings, stating that, after its own investigation last September, it determined that a mechanical failure in a gas cylinder''s pressure release valve led to the fire. The company claims to have removed and replaced 8,000 cylinders. Praxair also does not believe heat was a factor. On June 24, 2005, one propylene cylinder stored on asphalt on a day when the temperature reached 97 degrees caught fire and the blaze spread to propane and acetylene cylinders. Eventually, more than 8,000 cylinders caught fire, many shooting like missiles into the sky and into the residential neighborhood surrounding the plant. The cylinders damaged several homes and cars. No one died immediately after the fire, but 32-year-old Minnie Cooper died 11 days later because her brain was starved of oxygen.