OSC Hammack and OSC Delgado-
At approximately 1130 on 26 September 2006, two pressurized vessels containing toluene di-isocyanate (TDI) were undergoing maintenance activities when one of them increased in pressure and exploded. Twenty-two Bayer employees/contractors were impacted by the explosion and were transferred to local medical facilities. Twenty-one of the twenty-two were released from the hospital after minor care. One employee/contractor remains in care at Memorial Herman's burn center. This employee suffered 2nd degree burns on his back. His status was stable when the START was briefed by Bayer Wayne Baldwin (Bayer's Environmental Manager) at 1925.
The initial explosion of the vessel ruptured an ammonia unit near the incident area. The ammonia unit release and unknown quantity of ammonia into the air. The unit was impacted in such a way that ammonia continued to leak from the unit throughout the day. Bayer suppressed the ammonia gas with fire water until a better solution could be made. The firewater was captured within the facility's process storm sewer system, which flowed into their permitted waste water treatment plant.
Bayer's Health and Safety department monitored the ammonia levels downwind of the incident area after the explosion. The highest readings recorded were 5-ppm of ammonia from Draeger monitoring equipment. Detections of ammonia were recorded as far as approximately 0.5 miles downwind of the incident area, which was still within the fence line of the Bayer Chemical Facility. A small amount of ammonia continued to leak from the unit until approximately 1725 when Bayer placed a vacuum scrubber over the valve that was leaking.
Multiple agencies were on-site prior to STARTs arrival: TCEQ, OSHA, Harris County Pollution Control, Chemical Safety Board, Public Safety Department, and the U.S. Coast Guard.
The EPA START conducted air monitoring from the visitors parking lot (downwind of incident area) and obtained non-detect reading of ammonia. Currently, Bayer is not operating under in an emergency response mode. Bayer has mantained their ERT in case something occurs over the night. Bayer has shifted into their regular operations and maintenance activities that occur after an incident.
TCEQ and START plan to meet at the facility tomorrow morning to check on the status of the incident. START plans on entering the facility to photo document the incident area and to obtain any further information from Bayer.
