PHOSPHORUS INCIDENT IN COOPER COUNTRY MISSOURI
Written from contributions by Bill Simmons, chief of Cooper County Fire Protection District; John B. Sachen, chief of fire protection and chemical response for Mallinckrodt Specialty Chemicals Company, St. Louis, Missouri; Leo Tierney, director of hazardous-materials management for Union Pacific Railroad, Omaha, Nebraska; and the office of John Coburn, state fire marshal of Missouri.
The Union Pacific Railroad line between Kansas City and St. Louis, Missouri, is 250 miles of well-traveled track, much of it winding through rural countryside. Almost midpoint between the two cities lies Cooper County, a farming region just west of Columbia. Missouri. At approximately 10:50 a m. on Wednesday, February 20, 1991, as a 1 1 3-car, 6,500-foot-long freight train approached the eastern end of the county, a wheel broke on one of the cars, causing a 29-car derailment. Four of the derailed cars each contained 185,000 pounds of solidified elemental phosphorus un-
der water. One car was pierced by a section of broken rail. It is believed that the heat of ignition resulted from the friction of the rail piercing the car head, which rapidly raised the temperature of the phosphorus above its 86°F autoignition temperature.
Firefighters from the Cooper County Fire Protection District (a 30-member volunteer department protecting approximately 125 square miles of rural area with six apparatus), responded immediately after the derailment. along with members of state and local law enforcement agencies. From a distance they observed a small, white cloud rising from a cluster of tank cars. They requested a hazmat response vehicle from Boone County Fire Protection District, and then through shipping papers identified phosphorus as the source of the cloud. Together, firefighters from the two counties, in full turnout gear and SCBA, approached the area for a sizeup. They observed a two-foot-diameter pool of molten phosphorus on fire under one of the derailed tank cars, with flames two to three inches high. The phosphorus pentoxide cloud around the car was quite dense. The incident commander, Captain Jim Gann, called for additional alarms, isolated the area, established a hot zone and a command post, and, based in part on recommendations from CHEMTREC, decided to evacuate approximately 200 residents within a three-mile radius of the scene, including 80 residents from the nearby town of Woolridge. Evacuation was performed by the Cooper County Emergency Management Agency, whose members also manned entry points.
(Photo courtesy of Cooper County Fire Protection District and Boone County Fire Protection District.)
Shortly thereafter, Chief Bill Simmons of Cooper County FPI) arrived and assumed command. He established safety, haz-mat, and medical sectors; called the Columbia air supply team; and confirmed that representatives from the shipper, the carrier, and other agencies were en route.
In accordance with Union Pacific Railroad (UPRR) SOPs, the train crew’s call to its UPRR dispatch center triggered a series of notifications in addition to those initially placed to Cooper County responders. The National Response Center, CHEMTREC, The Missouri Department of Natural Resources, the shipper, UPRR’s toxic air-monitoring and derailment contractors, and local and regional l PRR haz-mat officials and service units all were notified.
Bob Stine, regional manager of hazardous-materials emergency response for UPRR, responded to the scene and reconned the area. He observed that the pool of phosphorus had grown considerably since initial size-up and that flames were now 24 to 36 inches high; however, the cloud was too dense to obtain an accurate damage assessment. Earlier, Stine had requested the assistance of Cliff Shupe, the St. Louis UPRR haz-mat specialist; Chief John Kriska of the Rock Hill (MO) Fire Department, a l PRR-trained responder, and John Sachen, chief of fire protection and chemical response for the Mallinckrodt Chemical Company in St. Louis. From Highway 1-70 the three observed a moderate-sized cloud with a lazy appearance. By the time they traveled the 10 miles to the command post for briefing at about 3:00 p.m., the fire had become more aggressive, and the cloud was pushing upward with noticeable force. Command formed an additional reconnaissance team, including Leo Tierney, director of hazardous-materials management for l JPRR, to obtain a current and complete size-up before discussing the hazards and mitigating options. T his recon confirmed that the intensified fire still was confined to the pool of spilled phosphorus in a depression under the car and that all of the top fittings on the car were intact.
T he fire was growing rapidly, and personnel at the command post knew they had to formulate a strategy and implement it as soon as possible. Since about one mile of corn and wheat fields separated the staging area from the spill site, command chose a four-wheel-drive brush truck, with tSO gallons of water, a permanently mounted portable pump, and 300 feet of 1 ‘/2-inch hoseline as the initial attack vehicle. On the recommendation of Chief Sachcn, they decided to attack the phosphorus with foam for several reasons: Foam would prohibit oxygen from contacting the product; water by itself would be effective on the fire only until it evaporated or ran off, at which time the phosphorus would reignite; two very sizable dams would have been needed to keep a water pool on top of the molten material; and substantially more water would have been required if foam had not been applied, and the resulting mud further would have complicated suppression and cleanup efforts. Four five-gallon containers of 3-6 polar solvent/AFFF, a 60-gpm aspirating foam nozzle, and pickup tube with shut-off capability were loaded on the truck.
(Left) Entry team personnel on the Cooper County brush truck approach the safety officer en route to the fire area. The truck carried polar solvent AFFF, 450 gallons of water, 1 ⅛-inch hose, a 60-gpm aspirating foam noziie, a pickup tube (eductor), and an 18-hp portable pump. Soft fields delayed the use of heavier vehicles until safe routes were confirmed later. (Top right) The rapidly growing fire as seen from the safety officer’s position at the hot zone entry point at approximately 4 p.m. The pink reflection of the aggressive fire—some 3,000 pounds of phosphorus burning with a sixto eight-foot flame front—is visible in the stark white smoke column. In light of the acceleration of the fire, the firefighting team had time only for a brief review before undertaking the attack. (Bottom right) Shortly after the application of foam on the fire, the smoke has cleared and the pool at the east end of the car is under control. (Photos by Bill Pratt.)
The entry team was a blend of eight personnel, five from UPRR/industrial sector and three from Cooper and Boone fire districts, all in full firefighter protection with SCBA. After checking with the safety officer at the entry to the hot zone, members proceeded directly to the burn area at the east end of the car. Flames were now between six to eight feet high and growing. Approximately 2,900 pounds of molten phosphorus had formed a pool that was eight feet in diameter and six to eight inches deep. The team stretched the hoseline and gently applied 3% foam solution to the car head, flowing the agent over the surface. The foam spread quietly over the phosphorus, extinguishing the flames and cooling the burning metal without the sputtering and steaming typical of water application.
The nozzle team used 1 3 gallons of foam and 250 gallons of water for knockdown while team members Kriska and Shupe created a dam with railroad tics at the south end of the spill to contain phosphorus spread and increase foam depth. Foam was periodically reapplied as heat from the still-spilling product and the metal railcar broke down the blanket. Members shoveled dirt away from the head of the tank ear and observed that a broken rail had punctured the ear, resulting in the phosphorus leak; fortunately, however, the rail had pierced the tank very cleanly, leaving a relatively tight joint around the entire perimeter of the rail that eliminated the possibility of a large, uncontrollable flow of molten phosphorus from the puncture. Mud was packed around the rail to seal the breech.
(Top left) View of the tank car involved in the fire. To the left is the head of the car (east end) punctured by the rail. Note that the smoke from the molten phosphorus at the east end and inside the annular space is evident at the outer steel jacket seams. To the right of the photo, a Cooper County firefighter moves into position to apply foam to the creek bed fire. (Top right) Molten phosphorus spills out of the west end of the burning car (lower right corner) and pools in the creek bed. (Bottom left) The firefighter applies foam to the molten phosphorus in the creek bed; the phosphorus, although similar in appearance to lava, does not cool and darken on exposure to air as lava does. (Bottom right) The low-velocity, indirect foam application technique employed on the fire. End-of-line foam pickup using foam nozzles with tubes works through a wide range of water flows, ensuring foam operation under almost all conditions. At low flows the foam will be rich. In both fires—in the east and west ends of the tank car—the foam rolled over the molten phosphorus with almost no spattering and a minimum of steaming. While the phosphorus was still hot, the draining solution steamed and reformed the foam blanket. (Photos by John B. Sachen.)
About an hour into operations, a 1 4-inch stream of phosphorus from the tank’s west end began spilling into a creek —the product had traveled through the insulation in the car’s annular space. Wood and leaves in the creek bed ignited on contact and increased the size of the fire until foam was applied. This second fire was controlled quickly. A water-filled livestock tank was set up at this time for a safety bath in case personnel contacted the product.
(Photo by John B. Sachen.)
Although the open fires were extinguished quickly, phosphorus absorbed by the insulation continued to smolder. At 2230 hours, team members located several breaks in the steel jacket over the insulation and applied foam solution through an open butt on the 1 Vi-inch hoseline into it. This action controlled the smoldering fire in the tank’s annular space.
STABILIZATION AND CLEANUP
Throughout the night, Cooper County firefighters, working jointly with members of the Boone County Fire Protection District, the Columbia Fire Department, the UPRR, and other mutual-aid response agencies, kept the scene stabilized through periodic suppression activity—the situation still was a potentially explosive one. Personnel took shifts sleeping in their trucks while the UPRR’s derailment contractor moved most of the derailed cars from the area. A full-size pumper was brought out to the scene, along with two folding tanks for additional water supply, 20 truckloads of sand to bury the leaking tank car if necessary, and 75 steel drums for collecting and packaging solidified product and contaminated soil. A water relay was set up, and handlines with foam eductors and nozzles were charged at all times.
By morning, agencies at the command post had agreed on the next Objective: cut the rail from the phosphorus car (as close to the car as possible), remove the outer skin of the car, then weld a field-fabricated steel box to the head of the tank car to enclose the protruding rail and stop the How. A local welding contractor was hired to weld the patch. While personnel removed more soil from the area to provide greater working space, large slabs of elemental phosphorus were found buried underneath. They were cleared away and placed in the water-filled steel drums.
The welding operation proved difficult and time-consuming. Each time the welder struck an arc to lay a bead, the phosphorus behind the tank’s shell melted and flowed in a thin stream to the outside, whereupon it ignited. Then the fire had to be extinguished with foam or mud, the two inches of just-welded bead had to be cleaned off, and the tank shell had to cool before two more inches of bead could be completed. All along, suppression activities were turning the area into a muddy mess, adding to the repair and cleanup difficulties.
During repair of the original car, a second damaged phosphorus tank car ignited. Welds between the car’s brake system support pipe and underside of the tank failed to release as designed. When the pipe bent in the derailment, a 10-inch-diameter hole was ripped open, exposing the phosphorus. The exposed phosphorus did not ignite immediately because the air temperature was below its 86°F autoignition temperature. Firefighters extinguished the fire immediately with foam. However, containment of this material put a further dent in already dwindling on-scene resources and complicated matters because this, too, would require a welded steel box to stop the flow.
By Thursday morning, based on information from firefighters, railroad officials, haz-mat specialists, cleanup contractors, and environmental testing agencies, it became apparent to Chief Simmons that an extended operation was inevitable and that greater resources were necessary. He contacted Steve Paulsell, chief of the Boone County FPI) and regional mutual-aid coordinator, and submitted anticipated resource needs for the operation. Paulsell in turn contacted State Fire Marshal John Coburn to initiate the newly formed statewide mutual-aid pact. Within an hour, resources from all over the state were en route to the scene. Eventually, what had begun as a firefighting crew of 30 grew to a task force of more than 200 firefighters from 62 departments.
More than 2½ days after operations began, the temporary tank repairs were accomplished. By 3 am. on Saturday, February 23, personnel had rerailed three of the phosphorus tank cars. The car with the head puncture was moved from the road bed into a holding pit so that mainline track could be replaced while the car was inspected. Inspection of the insulation at the east end of the first tank car indicated scorching and considerable heat transfer into the car. Subsequently, it was determined that phosphorus had solidified within the tanks’ annular spaces; during the next four days, UPRR personnel carefully removed some of the product for disposal. Several reignitions occurred; alcohol/ AFFF, wet mud, and wet sand were used effectively to blanket the phosphorus. Finally, on Wednesday, February 27—eight days after the incident began —the last phosphorus tank car was loaded on a fiat-bed and transported to an approved off-loading site.
LESSONS LEARNED AND REINFORCED
- Appropriate initial actions by first responders are key to the effective, low-risk mitigation of large-scale hazmat incidents. Conservative decisions by the first-in officer —call for additional units; isolate the area; identify the product; withdraw to a safe distance; consult CHEMTREC, the manufacturer, the shipper, and available literature; and evacuate residents if necessary—were consistent with the life-safety priority.
- Successful response to large-scale haz-mat incidents cannot occur without excellent cooperation among fire service, industry, and other agencies. A working relationship must be cultivated through planning, training, and drilling. Acknowledging each other’s duties, strengths, and weaknesses — and knowing when to take the reins or provide the support —is critical to smooth interagency operations under stressful conditions.
- The Cooper County incident demonstrated the effectiveness of foam for extinguishing phosphorus fires, one of the first cases in which this tactic was used in the field. The largest supplier of phosphorus has tested foam under controlled condi-
- tions, but high volumes of gently applied water have been the agent of choice. That company is in the process of revising its material safety data sheets to include 396-6% polar solvent/AFFF foam as a primary mitigating agent. Industry’ personnel at the scene were impressed w ith the small amount of water required to extinguish a relatively large fire with a fourhour preburn time. Wet earth and sand also were used effectively throughout the incident to control phosphorus reignition.
- As has been proven many times, initiating a mutual-aid system can be a turning point in a lengthy, large-scale
- incident requiring additional resources. Missouri’s statewide mutualaid pact worked effectively despite the fact that it was formed just five months prior to the incident. While some refinements are being made, particularly with respect to communications systems, scene congestion, and information on routes for responding units, officials are very pleased with the first real test of the system.
- Site coordination at such an incident is one of the incident commander’s greatest challenges. Using an incident command system and establishing sectors are essential *