Document jB8B3em71v2oMN5V7Xm19YQwO

Diamond Shamrock May 14, 1979 Mr. Richard Miller Industrial Hygienist Occupational Safety and Health Administration 1100 Nasa Road 1, Suite 505 Houston, Texas 77058 Dear Mr. Miller: At 0447 hours on May 9, 1979, a VCM release occurred at our Deer Park Polyvinyl Chloride Plant and seven (7), of our employees were exposed to VCM. The highest level recorded by our monitor ing system Was 3573 ppm/VCM. All of the employees exposed to VCM were examined by our First Aid Department and no neurological effects were reported. The names of the employees exposed are as follows: Jerry Pettit Tom Renfroe Mike Keener Hector Arrendondo Tom McCabe Martin Stultz Joe Jones Although each employee is provided with approved respirator equip ment, only one of the exposed employees was wearing respiratory protection. In reference to your question as to whether these employees would be given liver function tests as a result of their exposure, no special tests will be given at this time. However, the SMA-12 blood tests which includes the liver battery are included in the physical examina tion given annually to all Plastics employees and semi-annually to employees who have worked ten or more years in Plastics. If these tests indicate a liver problem; then more extensive tests, including a liver scan, are given. The VCM release amounted to 522 lbs/VCM and lasted for 18 minutes. The details of the release are as follows: Reactor #44 in the #4 Plant poly room was in the process of heat-up to batch temperature. When the batch pressure reached 102 psig, the follower ring, which holds the baffle packing in place, separated. The three packing rings lifted several inches and a small hole was OCC 11093 Diamond Shamrock Corporation P.O. Box 500, Deer Park, Texas 77536 Phone: 713 476-2000 Mr. Richard Miller Occupational Safety and Health Administration May 14, 1979 Page 2 ripped in the middle ring, allowing VCM vapor to escape to the atmo sphere. An operator immediately turned a water hose on the leak and the shift superintendent was notified. The shift superintendent arrived in 45 seconds and instructed two more operators to connect two additional hoses to the charge water manifold and turn them on the leak. He instructed a fourth operator to add the quick-kill solution to the reactor and told a fifth operator to line the reactor up to the emergency high pressure blowdown tank. Five minutes after the release began, the reactor contents were dropped to the emergency blowdown tank. Seven minutes after the release began, the reactor vent valve was manually opened, allowing additional vapors to be vented to the VCM recovery system through the VCM vacuum pump. Nine minutes after the release began, the pressure inside the reactor had dropped to 5 psig and after eighteen minutes, a vacuum had been pulled on the reactor. The cause of this release was the separation of the baffle packing follower split ring. The ring separated due to the breakage of one of two cast iron fastener clamps. To insure that this does not happen again, we will immediately replace all cast iron fastener clamps with steel clamps and additionally will design and install improved follower rings on all reactors at number 1, 2 and 4 poly rooms. The reactors in number 3 poly room are currently equipped with follower rings of a satisfactory design. Sincerely, Douglas E. Frey Plant Manager Plastics Division DEF:ja OCC 11094