Shell Chemical LR — Hazardous Materials Safety Interpretation

Page 1of Transportation US.Department 400 Seventh Street, S.W. Washington. D.C. 20590 Special Programs Research and caps: e. Administration Mr. David J. Mashinski HSE Advisor OCT 2.2:2002 Ref. No. 02-0199 Shell Chemical LP. A33 910 Louisiana Street 4101 Houston, Texas 77002-2463 Dear Mr. Mashinski: TC2T This is in response to your July 17, 2002 letter concerning attendance requirements for rail car : unloading under the Hazardous Materials Regulatións (HMR; 49 FR parts 171-180): Specifically, you ask if the attendance requirements apply to a tank car undergoing a steaming process that is not attached to an unloading process. You further state that the vapors are being vented through a valve on the car requirements as they apply to a steaming process during which vapors are vented through a valve On February 18, 2000, we provided you with a clarification of the rail car attendance that is connected via closed pipe to a permitted air pollution control device (Ref. No. 99-0301).. In addition, on November 15, 2001, we issued a letter of clarification to Koch Materials Company with the manway slightly open to relieve any potential pressure. Both letters stated that (Ref. No. 01-0269) concerning attendance requirements for a steaming process that is conducted interconnected with or part of the unloading process or if the steaming process is conducted with attendance is not required when a tank car is connected to a steaming device that is not all valves and manways closed. This statement apparently has resulted in some confusion as to the applicability of the attendance requirements to certain steaming operations. We are withdrawing letter Ref. No. 01-0269, which we issued on November 15, 2001. In that. letter, we erroneously affirmed an interpretation that would allow a tank car, undergoing a steaming process before unloading, to have an open manway without being attended. We apologize for the error and subsequent confusion this may have caused The attendance requirements set forth in $ 174.67(i) apply to a steaming operation that is connected to or part of the unloading process. Further, the attendance requirements apply when manways or valves are open to relieve pressure, either to the atmosphere or a pollution control device, during heating of a material in preparation for unloading, even if the steaming process is not connected to or part of the unloading process itself. Thus, the steaming process you describe is subject to the attendance requirements in § 174.67(i). I hope this information is helpful. If you have further questions, please do not hesitate to contact this office. 174.67 020199#

Page 2I hope this information is helpful. If you have further questions, please do not hesitate to contact this office. Sincerely, 4234: Edward Mazzullo Director, Office of Hazardous Materials Standards : V:#

Page 3Johnsen Shell Chemicals 3174.67 Rail 02-0199 July 17, 2002 Office of Hazardous Materials Standards - DHM -11 400 7' Street, S.W. U.S. Department Of Transportation Washington, D.C. 20590-0001 Dear Mr. Billings, Shell Chemical LP seeks clarification of the attendance requirements for unloading tank cars under the Hazardous Materials Regulations (ref. 49CFR 174.67). I spoke with Mike Johnson of your staff on July 11, 2002, regarding the attendance requirements of a tank car being heated with the use of steam. During the steaming process, the vapors are being vented through a valve in the car, which is connected via a closed pipe to a permitted air pollution control device (flare). The process of steaming the tank car is prior to and not interconnected with or part of the unloading process. We would appreciate your confirmation that the HMR does not require attendance in the above situation. Our thanks in advance for your prompt consideration of this request. I may be contacted at (713) 241-6436. Shell Chemical LP 910 Louisiana Street Houston, Texas 77002-2463 Sincerely, David Mashinski David Mashinski HSE Advisor AttendanceTC71702#