AMBAR Chemical — Hazardous Materials Safety Interpretation

Page 1U.S. Department of Transportation Research and Washington, D.C. Administrations. Mr. Greg Pyle MAR 24 2000 AMBAR Chemical Ref. No. 99-0185 1501 Main Street Manistee, MI 49660 Dear Mr. Pyle: This is in response to your letter regarding attendance requirements for unloading chlorine from railcars under the Hazardous Materials Regulations (HMR; 49 CFR Parts 171-180). I apologize for the delay in responding and hope it has not caused any inconvenience. You provided the following scenario: Ambar Chemical's unloading station is inside a building that is connected to an emergency caustic scrubber that has been designed to neutralize an entire railcar full of chlorine (90 tons). The railcar pressure and the valves used to isolate the railcar from the process can be remotely actuated from the bromine plant control room. There are chlorine detectors in the unloading building that transmit an alarm signal to the bromine plant control room whenever a chlorine level of 1 part per million is detected. The control room is occupied 24 hours a day. Currently, Ambar Chemical offloads chlorine only while one of the bromine plant technicians is physically within 25 feet of the railcar and can see the railcar unloading piping and valves. You asked, provided the non-human monitoring and control systems described above meet the attendance requirements of 49 CFR 174.67(i), if it is necessary to have a plant technician physically located within 25 feet of the railcar who can see the railcar unloading piping and valves. Under the HMR, Ambar Chemical's proposed system for non-human monitoring may meet the provided: attendance requirements in 49 CFR 174.67(a)(1) and (i) for unloading a railcar containing chlorine An employee is made responsible for unloading and is familiar with the nature and properties of the material being unloaded; 2) The employee responsible for unloading is instructed in the procedures to be followed during unloading and in the event of an emergency, and has the authority and ability to halt the flow of product immediately and take emergency action; 990185#

Page 2- 3) In the event of an emergency, the system must be capable of immediately halting the flow of product or alerting the employee responsible for unloading; The monitoring device must provide immediate notification of any malfunction to the person responsible for unloading, or the device is checked hourly for malfunctions. Amber Chemical should be aware that, in case of malfunction, the device (i.e., proposed non-human monitoring system) may no longer be relied upon and instead the individual responsible for unloading must constantly observe the unloading. I hope this satisfies your inquiry. If we can be of further assistance, please contact us. Sincerely, Delmer F. Billings Chief, Standards Development Office of Hazardous Materials Standards -#

Page 3Engrum AMBAR MANISTEE, MI 49660 1501 MAIN STREET 8174.67 CHEMICAL (616)723-3840 FAX (616) 723-6266 99-0185 July 13, 1999 Office of Hazardous Materials Standards Mr. Edward Mazzullo, Director 400 7" Street SW USDOT/RSPA (DHM-10) Washington, DC 20590 Dear Mr. Mazzullo: unloading of chlorine railcars at our Manistee, Michigan bromine facility and described our unloading I am writing this letter to you after speaking with Arthur Pollack on the hotline. I spoke with Arthur about system as follows: designed to neutralize an entire railcar full of chlorine (90 tons). The railcar pressure and the valves used to Our unloading station is inside a building that is connected to an emergency caustic scrubber that has been Isolate the railcar from the process can be remotely actuated from the bromine plant control room. Ir ddition, there are chlorine detectors in the unloading building that transmit an alarm signal to the bromine plant control room whenever a chlorine level of 1 part per million is detected. The control room is occupied 24 hrs per day. of the railcar and can see the railcar unloading piping and valves. This is done due to our interpretation of Currently, we offload chlorine only while one of the bromine plant technicians is physically within 25 feet needed to write this letter to you to get written confirmation for our records of his response. I appreciate your time in reading this letter and look forward to hearing from you soon. Sincerely yours, Mishe Greg Pyle cc: Arthur Pollock Bromine Plant Superintendent#