Inspection Detail

Inspection: 108914284 - Mansfield'S Industrial Coatings Inc.

Inspection Information - Office: Baton Rouge Area Office

Investigation Summary

At approximately 12:00 noon on March 5, 1991, at the Louisiana mill of International Paper, three 90 ton chlorine tank cars were at the loading area. Two pulp mill employees hooked up the east chlorine car. They tested for leaks and detected none. Upon entering their work station, approximately 100 ft north of the car, they heard a local alarm at the chlorine cars. With gas masks and a personal chlorine monitor, they returned to the car. They found a small leak at a valve packing on the car. Because even the smallest leaks are enough to activate the monitors, which are set at 0.5 ppm, they assumed they had found the source. One employee returned to the work station to get a wrench to tighten the packing. The remaining employee then noticed that the pulldown line had begun to ice up. He looked at all three pulldown valves on the car and each appeared to be closed. He pushed up on them to be sure. At that time, the high ORP alarm on the hypo collecting tank in the bleach plant sounded in the control room. The control room operator cut the chlorine off the bleach liquor maker and had the chlorine hand valve also cut off. He paged the employee at the car, who went to the two chlorine vaporizers and opened and closed each pulldown valve to be sure they were closed. The operator, at this time, realized that a significant emission had occurred but was now stopped. The employees estimate that 3 to 5 minutes elapsed from the time they finished hooking up the car until the valve on the south vaporizer was opened and closed. Total released chlorine was estimated to be between 500 and 1,200 lb. Five International Paper (IP) employees were in a pickup truck returning to their jobs. They were on the east side of the evaporator proceeding north when the release occurred. There was a strong wind blowing from the south; the driver stopped the truck just south of the evaporator cooling tower. All five employees got out of the truck and four proceeded north. Of the four who proceeded north, three were hospitalized. A driver of a dumpster truck ahead of the pickup was hospitalized, although his passenger was not. He had driven north until he thought he was out of the chlorine. An employee on a bicycle just ahead of the dumpster needed cough syrup, but was otherwise unaffected. Three contractor employees, who were working and eating lunch approximately 200 feet northwest of the blowdown, were hospitalized. An additional three IP employees and ten contractor employees were treated at Mill Health Services. Thirteen BE&K employees were treated at their first aid station. No IP employees had respirators with them because they were only passing through the area and not leaving the road. All hospitalized contractor employees used respirators, but used them too late to be effective. Inspection of the pulldown valve on the south vaporizer showed that the stop on the valve handle was incorrectly positioned so that the vale was partially open when it appeared to be closed. Also, the ORP probe alarm in the blowdown did not function because a conductor was broken.

Keywords: RAILROAD TANK CAR, CHLORINE, ACCIDENTAL DISCHARGE, INHALATION, VALVE, RESPIRATOR, INADEQUATE MAINT